garm/runner/pool/pool.go

// Copyright 2022 Cloudbase Solutions SRL
//
//    Licensed under the Apache License, Version 2.0 (the "License"); you may
//    not use this file except in compliance with the License. You may obtain
//    a copy of the License at
//
//         http://www.apache.org/licenses/LICENSE-2.0
//
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
//    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
//    License for the specific language governing permissions and limitations
//    under the License.

package pool

import (
	"context"
	"fmt"
	"log/slog"
	"math"
	"net/http"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/google/go-github/v57/github"
	"github.com/google/uuid"
	"github.com/pkg/errors"
	"golang.org/x/sync/errgroup"

	runnerErrors "github.com/cloudbase/garm-provider-common/errors"
	commonParams "github.com/cloudbase/garm-provider-common/params"
	"github.com/cloudbase/garm-provider-common/util"
	"github.com/cloudbase/garm/auth"
	dbCommon "github.com/cloudbase/garm/database/common"
	"github.com/cloudbase/garm/database/watcher"
	"github.com/cloudbase/garm/params"
	"github.com/cloudbase/garm/runner/common"
	garmUtil "github.com/cloudbase/garm/util"
)

var (
	poolIDLabelprefix     = "runner-pool-id:"
	controllerLabelPrefix = "runner-controller-id:"
	// We tag runners that have been spawned as a result of a queued job with the job ID
	// that spawned them. There is no way to guarantee that the runner spawned in response to a particular
	// job, will be picked up by that job. We mark them so as in the very likely event that the runner
	// has picked up a different job, we can clear the lock on the job that spaned it.
	// The job it picked up would already be transitioned to in_progress so it will be ignored by the
	// consume loop.
	jobLabelPrefix = "in_response_to_job:"
)

const (
	// maxCreateAttempts is the number of times we will attempt to create an instance
	// before we give up.
	//
	// nolint:golangci-lint,godox
	// TODO: make this configurable(?)
	maxCreateAttempts = 5
)

func NewEntityPoolManager(ctx context.Context, entity params.GithubEntity, instanceTokenGetter auth.InstanceTokenGetter, providers map[string]common.Provider, store dbCommon.Store) (common.PoolManager, error) {
	ctx = garmUtil.WithContext(ctx, slog.Any("pool_mgr", entity.String()), slog.Any("pool_type", entity.EntityType))
	ghc, err := garmUtil.GithubClient(ctx, entity, entity.Credentials)
	if err != nil {
		return nil, errors.Wrap(err, "getting github client")
	}

	if entity.WebhookSecret == "" {
		return nil, errors.New("webhook secret is empty")
	}

	controllerInfo, err := store.ControllerInfo()
	if err != nil {
		return nil, errors.Wrap(err, "getting controller info")
	}

	consumerID := fmt.Sprintf("pool-manager-%s-%s", entity.String(), entity.Credentials.Endpoint.Name)
	slog.InfoContext(ctx, "registering consumer", "consumer_id", consumerID)
	consumer, err := watcher.RegisterConsumer(
		ctx, consumerID,
		composeWatcherFilters(entity),
	)
	if err != nil {
		return nil, errors.Wrap(err, "registering consumer")
	}

	wg := &sync.WaitGroup{}
	keyMuxes := &keyMutex{}

	repo := &basePoolManager{
		ctx:                 ctx,
		entity:              entity,
		ghcli:               ghc,
		controllerInfo:      controllerInfo,
		instanceTokenGetter: instanceTokenGetter,

		store:     store,
		providers: providers,
		quit:      make(chan struct{}),
		wg:        wg,
		keyMux:    keyMuxes,
		consumer:  consumer,
	}
	return repo, nil
}

type basePoolManager struct {
	ctx                 context.Context
	entity              params.GithubEntity
	ghcli               common.GithubClient
	controllerInfo      params.ControllerInfo
	instanceTokenGetter auth.InstanceTokenGetter
	consumer            dbCommon.Consumer

	store dbCommon.Store

	providers map[string]common.Provider
	tools     []commonParams.RunnerApplicationDownload
	quit      chan struct{}

	managerIsRunning   bool
	managerErrorReason string

	mux    sync.Mutex
	wg     *sync.WaitGroup
	keyMux *keyMutex
}

func (r *basePoolManager) HandleWorkflowJob(job params.WorkflowJob) error {
	if err := r.ValidateOwner(job); err != nil {
		return errors.Wrap(err, "validating owner")
	}

	var jobParams params.Job
	var err error
	var triggeredBy int64
	defer func() {
		// we're updating the job in the database, regardless of whether it was successful or not.
		// or if it was meant for this pool or not. Github will send the same job data to all hierarchies
		// that have been configured to work with garm. Updating the job at all levels should yield the same
		// outcome in the db.
		if jobParams.ID == 0 {
			return
		}

		_, err := r.store.GetJobByID(r.ctx, jobParams.ID)
		if err != nil {
			if !errors.Is(err, runnerErrors.ErrNotFound) {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to get job",
					"job_id", jobParams.ID)
				return
			}
			// This job is new to us. Check if we have a pool that can handle it.
			potentialPools, err := r.store.FindPoolsMatchingAllTags(r.ctx, r.entity.EntityType, r.entity.ID, jobParams.Labels)
			if err != nil {
				slog.With(slog.Any("error", err)).WarnContext(
					r.ctx, "failed to find pools matching tags; not recording job",
					"requested_tags", strings.Join(jobParams.Labels, ", "))
				return
			}
			if len(potentialPools) == 0 {
				slog.WarnContext(
					r.ctx, "no pools matching tags; not recording job",
					"requested_tags", strings.Join(jobParams.Labels, ", "))
				return
			}
		}

		if _, jobErr := r.store.CreateOrUpdateJob(r.ctx, jobParams); jobErr != nil {
			slog.With(slog.Any("error", jobErr)).ErrorContext(
				r.ctx, "failed to update job", "job_id", jobParams.ID)
		}

		if triggeredBy != 0 && jobParams.ID != triggeredBy {
			// The triggeredBy value is only set by the "in_progress" webhook. The runner that
			// transitioned to in_progress was created as a result of a different queued job. If that job is
			// still queued and we don't remove the lock, it will linger until the lock timeout is reached.
			// That may take a long time, so we break the lock here and allow it to be scheduled again.
			if err := r.store.BreakLockJobIsQueued(r.ctx, triggeredBy); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to break lock for job",
					"job_id", triggeredBy)
			}
		}
	}()

	switch job.Action {
	case "queued":
		// Record the job in the database. Queued jobs will be picked up by the consumeQueuedJobs() method
		// when reconciling.
		jobParams, err = r.paramsWorkflowJobToParamsJob(job)
		if err != nil {
			return errors.Wrap(err, "converting job to params")
		}
	case "completed":
		jobParams, err = r.paramsWorkflowJobToParamsJob(job)
		if err != nil {
			if errors.Is(err, runnerErrors.ErrNotFound) {
				// Unassigned jobs will have an empty runner_name.
				// We also need to ignore not found errors, as we may get a webhook regarding
				// a workflow that is handled by a runner at a different hierarchy level.
				return nil
			}
			return errors.Wrap(err, "converting job to params")
		}

		// If job was not assigned to a runner, we can ignore it.
		if jobParams.RunnerName == "" {
			slog.InfoContext(
				r.ctx, "job never got assigned to a runner, ignoring")
			return nil
		}

		// update instance workload state.
		if _, err := r.setInstanceRunnerStatus(jobParams.RunnerName, params.RunnerTerminated); err != nil {
			if errors.Is(err, runnerErrors.ErrNotFound) {
				return nil
			}
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "failed to update runner status",
				"runner_name", util.SanitizeLogEntry(jobParams.RunnerName))
			return errors.Wrap(err, "updating runner")
		}
		slog.DebugContext(
			r.ctx, "marking instance as pending_delete",
			"runner_name", util.SanitizeLogEntry(jobParams.RunnerName))
		if _, err := r.setInstanceStatus(jobParams.RunnerName, commonParams.InstancePendingDelete, nil); err != nil {
			if errors.Is(err, runnerErrors.ErrNotFound) {
				return nil
			}
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "failed to update runner status",
				"runner_name", util.SanitizeLogEntry(jobParams.RunnerName))
			return errors.Wrap(err, "updating runner")
		}
	case "in_progress":
		jobParams, err = r.paramsWorkflowJobToParamsJob(job)
		if err != nil {
			if errors.Is(err, runnerErrors.ErrNotFound) {
				// This is most likely a runner we're not managing. If we define a repo from within an org
				// and also define that same org, we will get a hook from github from both the repo and the org
				// regarding the same workflow. We look for the runner in the database, and make sure it exists and is
				// part of a pool that this manager is responsible for. A not found error here will most likely mean
				// that we are not responsible for that runner, and we should ignore it.
				return nil
			}
			return errors.Wrap(err, "converting job to params")
		}

		// update instance workload state.
		instance, err := r.setInstanceRunnerStatus(jobParams.RunnerName, params.RunnerActive)
		if err != nil {
			if errors.Is(err, runnerErrors.ErrNotFound) {
				return nil
			}
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "failed to update runner status",
				"runner_name", util.SanitizeLogEntry(jobParams.RunnerName))
			return errors.Wrap(err, "updating runner")
		}
		// Set triggeredBy here so we break the lock on any potential queued job.
		triggeredBy = jobIDFromLabels(instance.AditionalLabels)

		// A runner has picked up the job, and is now running it. It may need to be replaced if the pool has
		// a minimum number of idle runners configured.
		pool, err := r.store.GetEntityPool(r.ctx, r.entity, instance.PoolID)
		if err != nil {
			return errors.Wrap(err, "getting pool")
		}
		if err := r.ensureIdleRunnersForOnePool(pool); err != nil {
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "error ensuring idle runners for pool",
				"pool_id", pool.ID)
		}
	}
	return nil
}

func jobIDFromLabels(labels []string) int64 {
	for _, lbl := range labels {
		if strings.HasPrefix(lbl, jobLabelPrefix) {
			jobID, err := strconv.ParseInt(lbl[len(jobLabelPrefix):], 10, 64)
			if err != nil {
				return 0
			}
			return jobID
		}
	}
	return 0
}

func (r *basePoolManager) startLoopForFunction(f func() error, interval time.Duration, name string, alwaysRun bool) {
	slog.InfoContext(
		r.ctx, "starting loop for entity",
		"loop_name", name)
	ticker := time.NewTicker(interval)
	r.wg.Add(1)

	defer func() {
		slog.InfoContext(
			r.ctx, "pool loop exited",
			"loop_name", name)
		ticker.Stop()
		r.wg.Done()
	}()

	for {
		shouldRun := r.managerIsRunning
		if alwaysRun {
			shouldRun = true
		}
		switch shouldRun {
		case true:
			select {
			case <-ticker.C:
				if err := f(); err != nil {
					slog.With(slog.Any("error", err)).ErrorContext(
						r.ctx, "error in loop",
						"loop_name", name)
					if errors.Is(err, runnerErrors.ErrUnauthorized) {
						r.setPoolRunningState(false, err.Error())
					}
				}
			case <-r.ctx.Done():
				// daemon is shutting down.
				return
			case <-r.quit:
				// this worker was stopped.
				return
			}
		default:
			select {
			case <-r.ctx.Done():
				// daemon is shutting down.
				return
			case <-r.quit:
				// this worker was stopped.
				return
			default:
				r.waitForTimeoutOrCancelled(common.BackoffTimer)
			}
		}
	}
}

func (r *basePoolManager) updateTools() error {
	// Update tools cache.
	tools, err := r.FetchTools()
	if err != nil {
		slog.With(slog.Any("error", err)).ErrorContext(
			r.ctx, "failed to update tools for entity", "entity", r.entity.String())
		r.setPoolRunningState(false, err.Error())
		return fmt.Errorf("failed to update tools for entity %s: %w", r.entity.String(), err)
	}
	r.mux.Lock()
	r.tools = tools
	r.mux.Unlock()

	slog.DebugContext(r.ctx, "successfully updated tools")
	r.setPoolRunningState(true, "")
	return err
}

// cleanupOrphanedProviderRunners compares runners in github with local runners and removes
// any local runners that are not present in Github. Runners that are "idle" in our
// provider, but do not exist in github, will be removed. This can happen if the
// garm was offline while a job was executed by a github action. When this
// happens, github will remove the ephemeral worker and send a webhook our way.
// If we were offline and did not process the webhook, the instance will linger.
// We need to remove it from the provider and database.
func (r *basePoolManager) cleanupOrphanedProviderRunners(runners []*github.Runner) error {
	dbInstances, err := r.store.ListEntityInstances(r.ctx, r.entity)
	if err != nil {
		return errors.Wrap(err, "fetching instances from db")
	}

	runnerNames := map[string]bool{}
	for _, run := range runners {
		if !isManagedRunner(labelsFromRunner(run), r.controllerInfo.ControllerID.String()) {
			slog.DebugContext(
				r.ctx, "runner is not managed by a pool we manage",
				"runner_name", run.GetName())
			continue
		}
		runnerNames[*run.Name] = true
	}

	for _, instance := range dbInstances {
		lockAcquired := r.keyMux.TryLock(instance.Name)
		if !lockAcquired {
			slog.DebugContext(
				r.ctx, "failed to acquire lock for instance",
				"runner_name", instance.Name)
			continue
		}
		defer r.keyMux.Unlock(instance.Name, false)

		switch instance.Status {
		case commonParams.InstancePendingCreate,
			commonParams.InstancePendingDelete, commonParams.InstancePendingForceDelete:
			// this instance is in the process of being created or is awaiting deletion.
			// Instances in pending_create did not get a chance to register themselves in,
			// github so we let them be for now.
			continue
		}

		pool, err := r.store.GetEntityPool(r.ctx, r.entity, instance.PoolID)
		if err != nil {
			return errors.Wrap(err, "fetching instance pool info")
		}

		switch instance.RunnerStatus {
		case params.RunnerPending, params.RunnerInstalling:
			if time.Since(instance.UpdatedAt).Minutes() < float64(pool.RunnerTimeout()) {
				// runner is still installing. We give it a chance to finish.
				slog.DebugContext(
					r.ctx, "runner is still installing, give it a chance to finish",
					"runner_name", instance.Name)
				continue
			}
		}

		if time.Since(instance.UpdatedAt).Minutes() < 5 {
			// instance was updated recently. We give it a chance to register itself in github.
			slog.DebugContext(
				r.ctx, "instance was updated recently, skipping check",
				"runner_name", instance.Name)
			continue
		}

		if ok := runnerNames[instance.Name]; !ok {
			// Set pending_delete on DB field. Allow consolidate() to remove it.
			if _, err := r.setInstanceStatus(instance.Name, commonParams.InstancePendingDelete, nil); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to update runner",
					"runner_name", instance.Name)
				return errors.Wrap(err, "updating runner")
			}
		}
	}
	return nil
}

// reapTimedOutRunners will mark as pending_delete any runner that has a status
// of "running" in the provider, but that has not registered with Github, and has
// received no new updates in the configured timeout interval.
func (r *basePoolManager) reapTimedOutRunners(runners []*github.Runner) error {
	dbInstances, err := r.store.ListEntityInstances(r.ctx, r.entity)
	if err != nil {
		return errors.Wrap(err, "fetching instances from db")
	}

	runnersByName := map[string]*github.Runner{}
	for _, run := range runners {
		if !isManagedRunner(labelsFromRunner(run), r.controllerInfo.ControllerID.String()) {
			slog.DebugContext(
				r.ctx, "runner is not managed by a pool we manage",
				"runner_name", run.GetName())
			continue
		}
		runnersByName[*run.Name] = run
	}

	for _, instance := range dbInstances {
		slog.DebugContext(
			r.ctx, "attempting to lock instance",
			"runner_name", instance.Name)
		lockAcquired := r.keyMux.TryLock(instance.Name)
		if !lockAcquired {
			slog.DebugContext(
				r.ctx, "failed to acquire lock for instance",
				"runner_name", instance.Name)
			continue
		}
		defer r.keyMux.Unlock(instance.Name, false)

		pool, err := r.store.GetEntityPool(r.ctx, r.entity, instance.PoolID)
		if err != nil {
			return errors.Wrap(err, "fetching instance pool info")
		}
		if time.Since(instance.UpdatedAt).Minutes() < float64(pool.RunnerTimeout()) {
			continue
		}

		// There are 3 cases (currently) where we consider a runner as timed out:
		//   * The runner never joined github within the pool timeout
		//   * The runner managed to join github, but the setup process failed later and the runner
		//     never started on the instance.
		//   * A JIT config was created, but the runner never joined github.
		if runner, ok := runnersByName[instance.Name]; !ok || runner.GetStatus() == "offline" {
			slog.InfoContext(
				r.ctx, "reaping timed-out/failed runner",
				"runner_name", instance.Name)
			if err := r.DeleteRunner(instance, false, false); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to update runner status",
					"runner_name", instance.Name)
				return errors.Wrap(err, "updating runner")
			}
		}
	}
	return nil
}

// cleanupOrphanedGithubRunners will forcefully remove any github runners that appear
// as offline and for which we no longer have a local instance.
// This may happen if someone manually deletes the instance in the provider. We need to
// first remove the instance from github, and then from our database.
func (r *basePoolManager) cleanupOrphanedGithubRunners(runners []*github.Runner) error {
	poolInstanceCache := map[string][]commonParams.ProviderInstance{}
	g, ctx := errgroup.WithContext(r.ctx)
	for _, runner := range runners {
		if !isManagedRunner(labelsFromRunner(runner), r.controllerInfo.ControllerID.String()) {
			slog.DebugContext(
				r.ctx, "runner is not managed by a pool we manage",
				"runner_name", runner.GetName())
			continue
		}

		status := runner.GetStatus()
		if status != "offline" {
			// Runner is online. Ignore it.
			continue
		}

		dbInstance, err := r.store.GetInstanceByName(r.ctx, *runner.Name)
		if err != nil {
			if !errors.Is(err, runnerErrors.ErrNotFound) {
				return errors.Wrap(err, "fetching instance from DB")
			}
			// We no longer have a DB entry for this instance, and the runner appears offline in github.
			// Previous forceful removal may have failed?
			slog.InfoContext(
				r.ctx, "Runner has no database entry in garm, removing from github",
				"runner_name", runner.GetName())
			resp, err := r.ghcli.RemoveEntityRunner(r.ctx, runner.GetID())
			if err != nil {
				// Removed in the meantime?
				if resp != nil && resp.StatusCode == http.StatusNotFound {
					continue
				}
				return errors.Wrap(err, "removing runner")
			}
			continue
		}

		switch dbInstance.Status {
		case commonParams.InstancePendingDelete, commonParams.InstanceDeleting:
			// already marked for deletion or is in the process of being deleted.
			// Let consolidate take care of it.
			continue
		case commonParams.InstancePendingCreate, commonParams.InstanceCreating:
			// instance is still being created. We give it a chance to finish.
			slog.DebugContext(
				r.ctx, "instance is still being created, give it a chance to finish",
				"runner_name", dbInstance.Name)
			continue
		case commonParams.InstanceRunning:
			// this check is not strictly needed, but can help avoid unnecessary strain on the provider.
			// At worst, we will have a runner that is offline in github for 5 minutes before we reap it.
			if time.Since(dbInstance.UpdatedAt).Minutes() < 5 {
				// instance was updated recently. We give it a chance to register itself in github.
				slog.DebugContext(
					r.ctx, "instance was updated recently, skipping check",
					"runner_name", dbInstance.Name)
				continue
			}
		}

		pool, err := r.store.GetEntityPool(r.ctx, r.entity, dbInstance.PoolID)
		if err != nil {
			return errors.Wrap(err, "fetching pool")
		}

		// check if the provider still has the instance.
		provider, ok := r.providers[pool.ProviderName]
		if !ok {
			return fmt.Errorf("unknown provider %s for pool %s", pool.ProviderName, pool.ID)
		}

		var poolInstances []commonParams.ProviderInstance
		poolInstances, ok = poolInstanceCache[pool.ID]
		if !ok {
			slog.DebugContext(
				r.ctx, "updating instances cache for pool",
				"pool_id", pool.ID)
			poolInstances, err = provider.ListInstances(r.ctx, pool.ID)
			if err != nil {
				return errors.Wrapf(err, "fetching instances for pool %s", pool.ID)
			}
			poolInstanceCache[pool.ID] = poolInstances
		}

		lockAcquired := r.keyMux.TryLock(dbInstance.Name)
		if !lockAcquired {
			slog.DebugContext(
				r.ctx, "failed to acquire lock for instance",
				"runner_name", dbInstance.Name)
			continue
		}

		// See: https://golang.org/doc/faq#closures_and_goroutines
		runner := runner
		g.Go(func() error {
			deleteMux := false
			defer func() {
				r.keyMux.Unlock(dbInstance.Name, deleteMux)
			}()
			providerInstance, ok := instanceInList(dbInstance.Name, poolInstances)
			if !ok {
				// The runner instance is no longer on the provider, and it appears offline in github.
				// It should be safe to force remove it.
				slog.InfoContext(
					r.ctx, "Runner instance is no longer on the provider, removing from github",
					"runner_name", dbInstance.Name)
				resp, err := r.ghcli.RemoveEntityRunner(r.ctx, runner.GetID())
				if err != nil {
					// Removed in the meantime?
					if resp != nil && resp.StatusCode == http.StatusNotFound {
						slog.DebugContext(
							r.ctx, "runner disappeared from github",
							"runner_name", dbInstance.Name)
					} else {
						return errors.Wrap(err, "removing runner from github")
					}
				}
				// Remove the database entry for the runner.
				slog.InfoContext(
					r.ctx, "Removing from database",
					"runner_name", dbInstance.Name)
				if err := r.store.DeleteInstance(ctx, dbInstance.PoolID, dbInstance.Name); err != nil {
					return errors.Wrap(err, "removing runner from database")
				}
				deleteMux = true
				return nil
			}

			if providerInstance.Status == commonParams.InstanceRunning {
				// instance is running, but github reports runner as offline. Log the event.
				// This scenario may require manual intervention.
				// Perhaps it just came online and github did not yet change it's status?
				slog.WarnContext(
					r.ctx, "instance is online but github reports runner as offline",
					"runner_name", dbInstance.Name)
				return nil
			}

			slog.InfoContext(
				r.ctx, "instance was found in stopped state; starting",
				"runner_name", dbInstance.Name)

			if err := provider.Start(r.ctx, dbInstance.ProviderID); err != nil {
				return errors.Wrapf(err, "starting instance %s", dbInstance.ProviderID)
			}
			return nil
		})
	}
	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return errors.Wrap(err, "removing orphaned github runners")
	}
	return nil
}

func (r *basePoolManager) waitForErrorGroupOrContextCancelled(g *errgroup.Group) error {
	if g == nil {
		return nil
	}

	done := make(chan error, 1)
	go func() {
		waitErr := g.Wait()
		done <- waitErr
	}()

	select {
	case err := <-done:
		return err
	case <-r.ctx.Done():
		return r.ctx.Err()
	}
}

func (r *basePoolManager) setInstanceRunnerStatus(runnerName string, status params.RunnerStatus) (params.Instance, error) {
	updateParams := params.UpdateInstanceParams{
		RunnerStatus: status,
	}
	instance, err := r.store.UpdateInstance(r.ctx, runnerName, updateParams)
	if err != nil {
		return params.Instance{}, errors.Wrap(err, "updating runner state")
	}
	return instance, nil
}

func (r *basePoolManager) setInstanceStatus(runnerName string, status commonParams.InstanceStatus, providerFault []byte) (params.Instance, error) {
	updateParams := params.UpdateInstanceParams{
		Status:        status,
		ProviderFault: providerFault,
	}

	instance, err := r.store.UpdateInstance(r.ctx, runnerName, updateParams)
	if err != nil {
		return params.Instance{}, errors.Wrap(err, "updating runner state")
	}
	return instance, nil
}

func (r *basePoolManager) AddRunner(ctx context.Context, poolID string, aditionalLabels []string) (err error) {
	pool, err := r.store.GetEntityPool(r.ctx, r.entity, poolID)
	if err != nil {
		return errors.Wrap(err, "fetching pool")
	}

	provider, ok := r.providers[pool.ProviderName]
	if !ok {
		return fmt.Errorf("unknown provider %s for pool %s", pool.ProviderName, pool.ID)
	}

	name := fmt.Sprintf("%s-%s", pool.GetRunnerPrefix(), util.NewID())
	labels := r.getLabelsForInstance(pool)

	jitConfig := make(map[string]string)
	var runner *github.Runner

	if !provider.DisableJITConfig() {
		// Attempt to create JIT config
		jitConfig, runner, err = r.ghcli.GetEntityJITConfig(ctx, name, pool, labels)
		if err != nil {
			slog.With(slog.Any("error", err)).ErrorContext(
				ctx, "failed to get JIT config, falling back to registration token")
		}
	}

	createParams := params.CreateInstanceParams{
		Name:              name,
		Status:            commonParams.InstancePendingCreate,
		RunnerStatus:      params.RunnerPending,
		OSArch:            pool.OSArch,
		OSType:            pool.OSType,
		CallbackURL:       r.controllerInfo.CallbackURL,
		MetadataURL:       r.controllerInfo.MetadataURL,
		CreateAttempt:     1,
		GitHubRunnerGroup: pool.GitHubRunnerGroup,
		AditionalLabels:   aditionalLabels,
		JitConfiguration:  jitConfig,
	}

	if runner != nil {
		createParams.AgentID = runner.GetID()
	}

	instance, err := r.store.CreateInstance(r.ctx, poolID, createParams)
	if err != nil {
		return errors.Wrap(err, "creating instance")
	}

	defer func() {
		if err != nil {
			if instance.ID != "" {
				if err := r.DeleteRunner(instance, false, false); err != nil {
					slog.With(slog.Any("error", err)).ErrorContext(
						ctx, "failed to cleanup instance",
						"runner_name", instance.Name)
				}
			}

			if runner != nil {
				_, runnerCleanupErr := r.ghcli.RemoveEntityRunner(r.ctx, runner.GetID())
				if err != nil {
					slog.With(slog.Any("error", runnerCleanupErr)).ErrorContext(
						ctx, "failed to remove runner",
						"gh_runner_id", runner.GetID())
				}
			}
		}
	}()

	return nil
}

func (r *basePoolManager) Status() params.PoolManagerStatus {
	r.mux.Lock()
	defer r.mux.Unlock()
	return params.PoolManagerStatus{
		IsRunning:     r.managerIsRunning,
		FailureReason: r.managerErrorReason,
	}
}

func (r *basePoolManager) waitForTimeoutOrCancelled(timeout time.Duration) {
	slog.DebugContext(
		r.ctx, fmt.Sprintf("sleeping for %.2f minutes", timeout.Minutes()))
	timer := time.NewTimer(timeout)
	defer timer.Stop()
	select {
	case <-timer.C:
	case <-r.ctx.Done():
	case <-r.quit:
	}
}

func (r *basePoolManager) setPoolRunningState(isRunning bool, failureReason string) {
	r.mux.Lock()
	r.managerErrorReason = failureReason
	r.managerIsRunning = isRunning
	r.mux.Unlock()
}

func (r *basePoolManager) getLabelsForInstance(pool params.Pool) []string {
	labels := []string{}
	for _, tag := range pool.Tags {
		labels = append(labels, tag.Name)
	}
	labels = append(labels, r.controllerLabel())
	labels = append(labels, r.poolLabel(pool.ID))
	return labels
}

func (r *basePoolManager) addInstanceToProvider(instance params.Instance) error {
	pool, err := r.store.GetEntityPool(r.ctx, r.entity, instance.PoolID)
	if err != nil {
		return errors.Wrap(err, "fetching pool")
	}

	provider, ok := r.providers[pool.ProviderName]
	if !ok {
		return fmt.Errorf("unknown provider %s for pool %s", pool.ProviderName, pool.ID)
	}

	jwtValidity := pool.RunnerTimeout()

	entity := r.entity.String()
	jwtToken, err := r.instanceTokenGetter.NewInstanceJWTToken(instance, entity, pool.PoolType(), jwtValidity)
	if err != nil {
		return errors.Wrap(err, "fetching instance jwt token")
	}

	hasJITConfig := len(instance.JitConfiguration) > 0

	bootstrapArgs := commonParams.BootstrapInstance{
		Name:              instance.Name,
		Tools:             r.tools,
		RepoURL:           r.GithubURL(),
		MetadataURL:       instance.MetadataURL,
		CallbackURL:       instance.CallbackURL,
		InstanceToken:     jwtToken,
		OSArch:            pool.OSArch,
		OSType:            pool.OSType,
		Flavor:            pool.Flavor,
		Image:             pool.Image,
		ExtraSpecs:        pool.ExtraSpecs,
		PoolID:            instance.PoolID,
		CACertBundle:      r.entity.Credentials.CABundle,
		GitHubRunnerGroup: instance.GitHubRunnerGroup,
		JitConfigEnabled:  hasJITConfig,
	}

	if !hasJITConfig {
		// We still need the labels here for situations where we don't have a JIT config generated.
		// This can happen if GARM is used against an instance of GHES older than version 3.10.
		// The labels field should be ignored by providers if JIT config is enabled.
		bootstrapArgs.Labels = r.getLabelsForInstance(pool)
	}

	var instanceIDToDelete string

	defer func() {
		if instanceIDToDelete != "" {
			if err := provider.DeleteInstance(r.ctx, instanceIDToDelete); err != nil {
				if !errors.Is(err, runnerErrors.ErrNotFound) {
					slog.With(slog.Any("error", err)).ErrorContext(
						r.ctx, "failed to cleanup instance",
						"provider_id", instanceIDToDelete)
				}
			}
		}
	}()

	providerInstance, err := provider.CreateInstance(r.ctx, bootstrapArgs)
	if err != nil {
		instanceIDToDelete = instance.Name
		return errors.Wrap(err, "creating instance")
	}

	if providerInstance.Status == commonParams.InstanceError {
		instanceIDToDelete = instance.ProviderID
		if instanceIDToDelete == "" {
			instanceIDToDelete = instance.Name
		}
	}

	updateInstanceArgs := r.updateArgsFromProviderInstance(providerInstance)
	if _, err := r.store.UpdateInstance(r.ctx, instance.Name, updateInstanceArgs); err != nil {
		return errors.Wrap(err, "updating instance")
	}
	return nil
}

// paramsWorkflowJobToParamsJob returns a params.Job from a params.WorkflowJob, and aditionally determines
// if the runner belongs to this pool or not. It will always return a valid params.Job, even if it errs out.
// This allows us to still update the job in the database, even if we determined that it wasn't necessarily meant
// for this pool.
// If garm manages multiple hierarchies (repos, org, enterprise) which involve the same repo, we will get a hook
// whenever a job involving our repo triggers a hook. So even if the job is picked up by a runner at the enterprise
// level, the repo and org still get a hook.
// We even get a hook if a particular job is picked up by a GitHub hosted runner. We don't know who will pick up the job
// until the "in_progress" event is sent and we can see which runner picked it up.
//
// We save the details of that job at every level, because we want to at least update the status of the job. We make
// decissions based on the status of saved jobs. A "queued" job will prompt garm to search for an appropriate pool
// and spin up a runner there if no other idle runner exists to pick it up.
func (r *basePoolManager) paramsWorkflowJobToParamsJob(job params.WorkflowJob) (params.Job, error) {
	asUUID, err := uuid.Parse(r.ID())
	if err != nil {
		return params.Job{}, errors.Wrap(err, "parsing pool ID as UUID")
	}

	jobParams := params.Job{
		ID:              job.WorkflowJob.ID,
		Action:          job.Action,
		RunID:           job.WorkflowJob.RunID,
		Status:          job.WorkflowJob.Status,
		Conclusion:      job.WorkflowJob.Conclusion,
		StartedAt:       job.WorkflowJob.StartedAt,
		CompletedAt:     job.WorkflowJob.CompletedAt,
		Name:            job.WorkflowJob.Name,
		GithubRunnerID:  job.WorkflowJob.RunnerID,
		RunnerName:      job.WorkflowJob.RunnerName,
		RunnerGroupID:   job.WorkflowJob.RunnerGroupID,
		RunnerGroupName: job.WorkflowJob.RunnerGroupName,
		RepositoryName:  job.Repository.Name,
		RepositoryOwner: job.Repository.Owner.Login,
		Labels:          job.WorkflowJob.Labels,
	}

	switch r.entity.EntityType {
	case params.GithubEntityTypeEnterprise:
		jobParams.EnterpriseID = &asUUID
	case params.GithubEntityTypeRepository:
		jobParams.RepoID = &asUUID
	case params.GithubEntityTypeOrganization:
		jobParams.OrgID = &asUUID
	default:
		return jobParams, errors.Errorf("unknown pool type: %s", r.entity.EntityType)
	}

	return jobParams, nil
}

func (r *basePoolManager) poolLabel(poolID string) string {
	return fmt.Sprintf("%s%s", poolIDLabelprefix, poolID)
}

func (r *basePoolManager) controllerLabel() string {
	return fmt.Sprintf("%s%s", controllerLabelPrefix, r.controllerInfo.ControllerID.String())
}

func (r *basePoolManager) updateArgsFromProviderInstance(providerInstance commonParams.ProviderInstance) params.UpdateInstanceParams {
	return params.UpdateInstanceParams{
		ProviderID:    providerInstance.ProviderID,
		OSName:        providerInstance.OSName,
		OSVersion:     providerInstance.OSVersion,
		Addresses:     providerInstance.Addresses,
		Status:        providerInstance.Status,
		ProviderFault: providerInstance.ProviderFault,
	}
}

func (r *basePoolManager) scaleDownOnePool(ctx context.Context, pool params.Pool) error {
	slog.DebugContext(
		ctx, "scaling down pool",
		"pool_id", pool.ID)
	if !pool.Enabled {
		slog.DebugContext(
			ctx, "pool is disabled, skipping scale down",
			"pool_id", pool.ID)
		return nil
	}

	existingInstances, err := r.store.ListPoolInstances(r.ctx, pool.ID)
	if err != nil {
		return fmt.Errorf("failed to ensure minimum idle workers for pool %s: %w", pool.ID, err)
	}

	idleWorkers := []params.Instance{}
	for _, inst := range existingInstances {
		// Idle runners that have been spawned and are still idle after 5 minutes, are take into
		// consideration for scale-down. The 5 minute grace period prevents a situation where a
		// "queued" workflow triggers the creation of a new idle runner, and this routine reaps
		// an idle runner before they have a chance to pick up a job.
		if inst.RunnerStatus == params.RunnerIdle && inst.Status == commonParams.InstanceRunning && time.Since(inst.UpdatedAt).Minutes() > 2 {
			idleWorkers = append(idleWorkers, inst)
		}
	}

	if len(idleWorkers) == 0 {
		return nil
	}

	surplus := float64(len(idleWorkers) - int(pool.MinIdleRunners))

	if surplus <= 0 {
		return nil
	}

	scaleDownFactor := 0.5 // could be configurable
	numScaleDown := int(math.Ceil(surplus * scaleDownFactor))

	if numScaleDown <= 0 || numScaleDown > len(idleWorkers) {
		return fmt.Errorf("invalid number of instances to scale down: %v, check your scaleDownFactor: %v", numScaleDown, scaleDownFactor)
	}

	g, _ := errgroup.WithContext(ctx)

	for _, instanceToDelete := range idleWorkers[:numScaleDown] {
		instanceToDelete := instanceToDelete

		lockAcquired := r.keyMux.TryLock(instanceToDelete.Name)
		if !lockAcquired {
			slog.With(slog.Any("error", err)).ErrorContext(
				ctx, "failed to acquire lock for instance",
				"provider_id", instanceToDelete.Name)
			continue
		}
		defer r.keyMux.Unlock(instanceToDelete.Name, false)

		g.Go(func() error {
			slog.InfoContext(
				ctx, "scaling down idle worker from pool",
				"runner_name", instanceToDelete.Name,
				"pool_id", pool.ID)
			if err := r.DeleteRunner(instanceToDelete, false, false); err != nil {
				return fmt.Errorf("failed to delete instance %s: %w", instanceToDelete.ID, err)
			}
			return nil
		})
	}

	if numScaleDown > 0 {
		// We just scaled down a runner for this pool. That means that if we have jobs that are
		// still queued in our DB, and those jobs should match this pool but have not been picked
		// up by a runner, they are most likely stale and can be removed. For now, we can simply
		// remove jobs older than 10 minutes.
		//
		// nolint:golangci-lint,godox
		// TODO: should probably allow aditional filters to list functions. Would help to filter by date
		// instead of returning a bunch of results and filtering manually.
		queued, err := r.store.ListEntityJobsByStatus(r.ctx, r.entity.EntityType, r.entity.ID, params.JobStatusQueued)
		if err != nil && !errors.Is(err, runnerErrors.ErrNotFound) {
			return errors.Wrap(err, "listing queued jobs")
		}

		for _, job := range queued {
			if time.Since(job.CreatedAt).Minutes() > 10 && pool.HasRequiredLabels(job.Labels) {
				if err := r.store.DeleteJob(ctx, job.ID); err != nil && !errors.Is(err, runnerErrors.ErrNotFound) {
					slog.With(slog.Any("error", err)).ErrorContext(
						ctx, "failed to delete job",
						"job_id", job.ID)
				}
			}
		}
	}

	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return fmt.Errorf("failed to scale down pool %s: %w", pool.ID, err)
	}
	return nil
}

func (r *basePoolManager) addRunnerToPool(pool params.Pool, aditionalLabels []string) error {
	if !pool.Enabled {
		return fmt.Errorf("pool %s is disabled", pool.ID)
	}

	poolInstanceCount, err := r.store.PoolInstanceCount(r.ctx, pool.ID)
	if err != nil {
		return fmt.Errorf("failed to list pool instances: %w", err)
	}

	if poolInstanceCount >= int64(pool.MaxRunners) {
		return fmt.Errorf("max workers (%d) reached for pool %s", pool.MaxRunners, pool.ID)
	}

	if err := r.AddRunner(r.ctx, pool.ID, aditionalLabels); err != nil {
		return fmt.Errorf("failed to add new instance for pool %s: %s", pool.ID, err)
	}
	return nil
}

func (r *basePoolManager) ensureIdleRunnersForOnePool(pool params.Pool) error {
	if !pool.Enabled || pool.MinIdleRunners == 0 {
		return nil
	}

	existingInstances, err := r.store.ListPoolInstances(r.ctx, pool.ID)
	if err != nil {
		return fmt.Errorf("failed to ensure minimum idle workers for pool %s: %w", pool.ID, err)
	}

	if uint(len(existingInstances)) >= pool.MaxRunners {
		slog.DebugContext(
			r.ctx, "max workers reached for pool, skipping idle worker creation",
			"max_runners", pool.MaxRunners,
			"pool_id", pool.ID)
		return nil
	}

	idleOrPendingWorkers := []params.Instance{}
	for _, inst := range existingInstances {
		if inst.RunnerStatus != params.RunnerActive && inst.RunnerStatus != params.RunnerTerminated {
			idleOrPendingWorkers = append(idleOrPendingWorkers, inst)
		}
	}

	var required int
	if len(idleOrPendingWorkers) < int(pool.MinIdleRunners) {
		// get the needed delta.
		required = int(pool.MinIdleRunners) - len(idleOrPendingWorkers)

		projectedInstanceCount := len(existingInstances) + required
		if uint(projectedInstanceCount) > pool.MaxRunners {
			// ensure we don't go above max workers
			delta := projectedInstanceCount - int(pool.MaxRunners)
			required -= delta
		}
	}

	for i := 0; i < required; i++ {
		slog.InfoContext(
			r.ctx, "adding new idle worker to pool",
			"pool_id", pool.ID)
		if err := r.AddRunner(r.ctx, pool.ID, nil); err != nil {
			return fmt.Errorf("failed to add new instance for pool %s: %w", pool.ID, err)
		}
	}
	return nil
}

func (r *basePoolManager) retryFailedInstancesForOnePool(ctx context.Context, pool params.Pool) error {
	if !pool.Enabled {
		return nil
	}
	slog.DebugContext(
		ctx, "running retry failed instances for pool",
		"pool_id", pool.ID)

	existingInstances, err := r.store.ListPoolInstances(r.ctx, pool.ID)
	if err != nil {
		return fmt.Errorf("failed to list instances for pool %s: %w", pool.ID, err)
	}

	g, errCtx := errgroup.WithContext(ctx)
	for _, instance := range existingInstances {
		instance := instance

		if instance.Status != commonParams.InstanceError {
			continue
		}
		if instance.CreateAttempt >= maxCreateAttempts {
			continue
		}

		slog.DebugContext(
			ctx, "attempting to retry failed instance",
			"runner_name", instance.Name)
		lockAcquired := r.keyMux.TryLock(instance.Name)
		if !lockAcquired {
			slog.DebugContext(
				ctx, "failed to acquire lock for instance",
				"runner_name", instance.Name)
			continue
		}

		g.Go(func() error {
			defer r.keyMux.Unlock(instance.Name, false)
			slog.DebugContext(
				ctx, "attempting to clean up any previous instance",
				"runner_name", instance.Name)
			// nolint:golangci-lint,godox
			// NOTE(gabriel-samfira): this is done in parallel. If there are many failed instances
			// this has the potential to create many API requests to the target provider.
			// TODO(gabriel-samfira): implement request throttling.
			if err := r.deleteInstanceFromProvider(errCtx, instance); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					ctx, "failed to delete instance from provider",
					"runner_name", instance.Name)
				// Bail here, otherwise we risk creating multiple failing instances, and losing track
				// of them. If Create instance failed to return a proper provider ID, we rely on the
				// name to delete the instance. If we don't bail here, and end up with multiple
				// instances with the same name, using the name to clean up failed instances will fail
				// on any subsequent call, unless the external or native provider takes into account
				// non unique names and loops over all of them. Something which is extremely hacky and
				// which we would rather avoid.
				return err
			}
			slog.DebugContext(
				ctx, "cleanup of previously failed instance complete",
				"runner_name", instance.Name)
			// nolint:golangci-lint,godox
			// TODO(gabriel-samfira): Incrementing CreateAttempt should be done within a transaction.
			// It's fairly safe to do here (for now), as there should be no other code path that updates
			// an instance in this state.
			var tokenFetched bool = len(instance.JitConfiguration) > 0
			updateParams := params.UpdateInstanceParams{
				CreateAttempt: instance.CreateAttempt + 1,
				TokenFetched:  &tokenFetched,
				Status:        commonParams.InstancePendingCreate,
				RunnerStatus:  params.RunnerPending,
			}
			slog.DebugContext(
				ctx, "queueing previously failed instance for retry",
				"runner_name", instance.Name)
			// Set instance to pending create and wait for retry.
			if _, err := r.store.UpdateInstance(r.ctx, instance.Name, updateParams); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					ctx, "failed to update runner status",
					"runner_name", instance.Name)
			}
			return nil
		})
	}
	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return fmt.Errorf("failed to retry failed instances for pool %s: %w", pool.ID, err)
	}
	return nil
}

func (r *basePoolManager) retryFailedInstances() error {
	pools, err := r.store.ListEntityPools(r.ctx, r.entity)
	if err != nil {
		return fmt.Errorf("error listing pools: %w", err)
	}
	g, ctx := errgroup.WithContext(r.ctx)
	for _, pool := range pools {
		pool := pool
		g.Go(func() error {
			if err := r.retryFailedInstancesForOnePool(ctx, pool); err != nil {
				return fmt.Errorf("retrying failed instances for pool %s: %w", pool.ID, err)
			}
			return nil
		})
	}

	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return fmt.Errorf("retrying failed instances: %w", err)
	}

	return nil
}

func (r *basePoolManager) scaleDown() error {
	pools, err := r.store.ListEntityPools(r.ctx, r.entity)
	if err != nil {
		return fmt.Errorf("error listing pools: %w", err)
	}
	g, ctx := errgroup.WithContext(r.ctx)
	for _, pool := range pools {
		pool := pool
		g.Go(func() error {
			slog.DebugContext(
				ctx, "running scale down for pool",
				"pool_id", pool.ID)
			return r.scaleDownOnePool(ctx, pool)
		})
	}
	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return fmt.Errorf("failed to scale down: %w", err)
	}
	return nil
}

func (r *basePoolManager) ensureMinIdleRunners() error {
	pools, err := r.store.ListEntityPools(r.ctx, r.entity)
	if err != nil {
		return fmt.Errorf("error listing pools: %w", err)
	}

	g, _ := errgroup.WithContext(r.ctx)
	for _, pool := range pools {
		pool := pool
		g.Go(func() error {
			return r.ensureIdleRunnersForOnePool(pool)
		})
	}

	if err := r.waitForErrorGroupOrContextCancelled(g); err != nil {
		return fmt.Errorf("failed to ensure minimum idle workers: %w", err)
	}
	return nil
}

func (r *basePoolManager) deleteInstanceFromProvider(ctx context.Context, instance params.Instance) error {
	pool, err := r.store.GetEntityPool(r.ctx, r.entity, instance.PoolID)
	if err != nil {
		return errors.Wrap(err, "fetching pool")
	}

	provider, ok := r.providers[pool.ProviderName]
	if !ok {
		return fmt.Errorf("unknown provider %s for pool %s", pool.ProviderName, pool.ID)
	}

	identifier := instance.ProviderID
	if identifier == "" {
		// provider did not return a provider ID?
		// try with name
		identifier = instance.Name
	}

	slog.DebugContext(
		ctx, "calling delete instance on provider",
		"runner_name", instance.Name,
		"provider_id", identifier)

	if err := provider.DeleteInstance(ctx, identifier); err != nil {
		return errors.Wrap(err, "removing instance")
	}

	return nil
}

func (r *basePoolManager) deletePendingInstances() error {
	instances, err := r.store.ListEntityInstances(r.ctx, r.entity)
	if err != nil {
		return fmt.Errorf("failed to fetch instances from store: %w", err)
	}

	slog.DebugContext(
		r.ctx, "removing instances in pending_delete")
	for _, instance := range instances {
		if instance.Status != commonParams.InstancePendingDelete && instance.Status != commonParams.InstancePendingForceDelete {
			// not in pending_delete status. Skip.
			continue
		}

		slog.InfoContext(
			r.ctx, "removing instance from pool",
			"runner_name", instance.Name,
			"pool_id", instance.PoolID)
		lockAcquired := r.keyMux.TryLock(instance.Name)
		if !lockAcquired {
			slog.InfoContext(
				r.ctx, "failed to acquire lock for instance",
				"runner_name", instance.Name)
			continue
		}

		currentStatus := instance.Status
		// Set the status to deleting before launching the goroutine that removes
		// the runner from the provider (which can take a long time).
		if _, err := r.setInstanceStatus(instance.Name, commonParams.InstanceDeleting, nil); err != nil {
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "failed to update runner status",
				"runner_name", instance.Name)
			r.keyMux.Unlock(instance.Name, false)
			continue
		}

		go func(instance params.Instance) (err error) {
			deleteMux := false
			defer func() {
				r.keyMux.Unlock(instance.Name, deleteMux)
			}()
			defer func(instance params.Instance) {
				if err != nil {
					slog.With(slog.Any("error", err)).ErrorContext(
						r.ctx, "failed to remove instance",
						"runner_name", instance.Name)
					// failed to remove from provider. Set status to previous value, which will retry
					// the operation.
					if _, err := r.setInstanceStatus(instance.Name, currentStatus, nil); err != nil {
						slog.With(slog.Any("error", err)).ErrorContext(
							r.ctx, "failed to update runner status",
							"runner_name", instance.Name)
					}
				}
			}(instance)

			slog.DebugContext(
				r.ctx, "removing instance from provider",
				"runner_name", instance.Name)
			err = r.deleteInstanceFromProvider(r.ctx, instance)
			if err != nil {
				if currentStatus != commonParams.InstancePendingForceDelete {
					return fmt.Errorf("failed to remove instance from provider: %w", err)
				}
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to remove instance from provider (continuing anyway)",
					"instance", instance.Name)
			}
			slog.InfoContext(
				r.ctx, "removing instance from database",
				"runner_name", instance.Name)
			if deleteErr := r.store.DeleteInstance(r.ctx, instance.PoolID, instance.Name); deleteErr != nil {
				return fmt.Errorf("failed to delete instance from database: %w", deleteErr)
			}
			deleteMux = true
			slog.InfoContext(
				r.ctx, "instance was successfully removed",
				"runner_name", instance.Name)
			return nil
		}(instance) //nolint
	}

	return nil
}

func (r *basePoolManager) addPendingInstances() error {
	// nolint:golangci-lint,godox
	// TODO: filter instances by status.
	instances, err := r.store.ListEntityInstances(r.ctx, r.entity)
	if err != nil {
		return fmt.Errorf("failed to fetch instances from store: %w", err)
	}
	for _, instance := range instances {
		if instance.Status != commonParams.InstancePendingCreate {
			// not in pending_create status. Skip.
			continue
		}

		slog.DebugContext(
			r.ctx, "attempting to acquire lock for instance",
			"runner_name", instance.Name,
			"action", "create_pending")
		lockAcquired := r.keyMux.TryLock(instance.Name)
		if !lockAcquired {
			slog.DebugContext(
				r.ctx, "failed to acquire lock for instance",
				"runner_name", instance.Name)
			continue
		}

		// Set the instance to "creating" before launching the goroutine. This will ensure that addPendingInstances()
		// won't attempt to create the runner a second time.
		if _, err := r.setInstanceStatus(instance.Name, commonParams.InstanceCreating, nil); err != nil {
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "failed to update runner status",
				"runner_name", instance.Name)
			r.keyMux.Unlock(instance.Name, false)
			// We failed to transition the instance to Creating. This means that garm will retry to create this instance
			// when the loop runs again and we end up with multiple instances.
			continue
		}

		go func(instance params.Instance) {
			defer r.keyMux.Unlock(instance.Name, false)
			slog.InfoContext(
				r.ctx, "creating instance in pool",
				"runner_name", instance.Name,
				"pool_id", instance.PoolID)
			if err := r.addInstanceToProvider(instance); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to add instance to provider",
					"runner_name", instance.Name)
				errAsBytes := []byte(err.Error())
				if _, statusErr := r.setInstanceStatus(instance.Name, commonParams.InstanceError, errAsBytes); statusErr != nil {
					slog.With(slog.Any("error", statusErr)).ErrorContext(
						r.ctx, "failed to update runner status",
						"runner_name", instance.Name)
				}
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to create instance in provider",
					"runner_name", instance.Name)
			}
		}(instance)
	}

	return nil
}

func (r *basePoolManager) Wait() error {
	done := make(chan struct{})
	timer := time.NewTimer(60 * time.Second)
	go func() {
		r.wg.Wait()
		timer.Stop()
		close(done)
	}()
	select {
	case <-done:
	case <-timer.C:
		return errors.Wrap(runnerErrors.ErrTimeout, "waiting for pool to stop")
	}
	return nil
}

func (r *basePoolManager) runnerCleanup() (err error) {
	slog.DebugContext(
		r.ctx, "running runner cleanup")
	runners, err := r.GetGithubRunners()
	if err != nil {
		return fmt.Errorf("failed to fetch github runners: %w", err)
	}

	if err := r.reapTimedOutRunners(runners); err != nil {
		return fmt.Errorf("failed to reap timed out runners: %w", err)
	}

	if err := r.cleanupOrphanedRunners(runners); err != nil {
		return fmt.Errorf("failed to cleanup orphaned runners: %w", err)
	}

	return nil
}

func (r *basePoolManager) cleanupOrphanedRunners(runners []*github.Runner) error {
	if err := r.cleanupOrphanedProviderRunners(runners); err != nil {
		return errors.Wrap(err, "cleaning orphaned instances")
	}

	if err := r.cleanupOrphanedGithubRunners(runners); err != nil {
		return errors.Wrap(err, "cleaning orphaned github runners")
	}

	return nil
}

func (r *basePoolManager) Start() error {
	initialToolUpdate := make(chan struct{}, 1)
	go func() {
		slog.Info("running initial tool update")
		if err := r.updateTools(); err != nil {
			slog.With(slog.Any("error", err)).Error("failed to update tools")
		}
		initialToolUpdate <- struct{}{}
	}()

	go r.runWatcher()
	go func() {
		select {
		case <-r.quit:
			return
		case <-r.ctx.Done():
			return
		case <-initialToolUpdate:
		}
		defer close(initialToolUpdate)
		go r.startLoopForFunction(r.runnerCleanup, common.PoolReapTimeoutInterval, "timeout_reaper", false)
		go r.startLoopForFunction(r.scaleDown, common.PoolScaleDownInterval, "scale_down", false)
		// always run the delete pending instances routine. This way we can still remove existing runners, even if the pool is not running.
		go r.startLoopForFunction(r.deletePendingInstances, common.PoolConsilitationInterval, "consolidate[delete_pending]", true)
		go r.startLoopForFunction(r.addPendingInstances, common.PoolConsilitationInterval, "consolidate[add_pending]", false)
		go r.startLoopForFunction(r.ensureMinIdleRunners, common.PoolConsilitationInterval, "consolidate[ensure_min_idle]", false)
		go r.startLoopForFunction(r.retryFailedInstances, common.PoolConsilitationInterval, "consolidate[retry_failed]", false)
		go r.startLoopForFunction(r.updateTools, common.PoolToolUpdateInterval, "update_tools", true)
		go r.startLoopForFunction(r.consumeQueuedJobs, common.PoolConsilitationInterval, "job_queue_consumer", false)
	}()
	return nil
}

func (r *basePoolManager) Stop() error {
	close(r.quit)
	return nil
}

func (r *basePoolManager) WebhookSecret() string {
	return r.entity.WebhookSecret
}

func (r *basePoolManager) ID() string {
	return r.entity.ID
}

// Delete runner will delete a runner from a pool. If forceRemove is set to true, any error received from
// the IaaS provider will be ignored and deletion will continue.
func (r *basePoolManager) DeleteRunner(runner params.Instance, forceRemove, bypassGHUnauthorizedError bool) error {
	if !r.managerIsRunning && !bypassGHUnauthorizedError {
		return runnerErrors.NewConflictError("pool manager is not running for %s", r.entity.String())
	}
	if runner.AgentID != 0 {
		resp, err := r.ghcli.RemoveEntityRunner(r.ctx, runner.AgentID)
		if err != nil {
			if resp != nil {
				switch resp.StatusCode {
				case http.StatusUnprocessableEntity:
					return errors.Wrapf(runnerErrors.ErrBadRequest, "removing runner: %q", err)
				case http.StatusNotFound:
					// Runner may have been deleted by a finished job, or manually by the user.
					slog.DebugContext(
						r.ctx, "runner was not found in github",
						"agent_id", runner.AgentID)
				case http.StatusUnauthorized:
					slog.With(slog.Any("error", err)).ErrorContext(r.ctx, "failed to remove runner from github")
					// Mark the pool as offline from this point forward
					r.setPoolRunningState(false, fmt.Sprintf("failed to remove runner: %q", err))
					slog.With(slog.Any("error", err)).ErrorContext(
						r.ctx, "failed to remove runner")
					if bypassGHUnauthorizedError {
						slog.Info("bypass github unauthorized error is set, marking runner for deletion")
						break
					}
					// evaluate the next switch case.
					fallthrough
				default:
					return errors.Wrap(err, "removing runner")
				}
			} else {
				errResp := &github.ErrorResponse{}
				if errors.As(err, &errResp) {
					if errResp.Response != nil && errResp.Response.StatusCode == http.StatusUnauthorized && bypassGHUnauthorizedError {
						slog.Info("bypass github unauthorized error is set, marking runner for deletion")
					} else {
						return errors.Wrap(err, "removing runner")
					}
				} else {
					// We got a nil response. Assume we are in error.
					return errors.Wrap(err, "removing runner")
				}
			}
		}
	}

	instanceStatus := commonParams.InstancePendingDelete
	if forceRemove {
		instanceStatus = commonParams.InstancePendingForceDelete
	}

	slog.InfoContext(
		r.ctx, "setting instance status",
		"runner_name", runner.Name,
		"status", instanceStatus)
	if _, err := r.setInstanceStatus(runner.Name, instanceStatus, nil); err != nil {
		slog.With(slog.Any("error", err)).ErrorContext(
			r.ctx, "failed to update runner",
			"runner_name", runner.Name)
		return errors.Wrap(err, "updating runner")
	}
	return nil
}

// consumeQueuedJobs will pull all the known jobs from the database and attempt to create a new
// runner in one of the pools it manages, if it matches the requested labels.
// This is a best effort attempt to consume queued jobs. We do not have any real way to know which
// runner from which pool will pick up a job we react to here. For example, the same job may be received
// by an enterprise manager, an org manager AND a repo manager. If an idle runner from another pool
// picks up the job after we created a runner in this pool, we will have an extra runner that may or may not
// have a job waiting for it.
// This is not a huge problem, as we have scale down logic which should remove any idle runners that have not
// picked up a job within a certain time frame. Also, the logic here should ensure that eventually, all known
// queued jobs will be consumed sooner or later.
//
// NOTE: jobs that were created while the garm instance was down, will be unknown to garm itself and will linger
// in queued state if the pools defined in garm have a minimum idle runner value set to 0. Simply put, garm won't
// know about the queued jobs that we didn't get a webhook for. Listing all jobs on startup is not feasible, as
// an enterprise may have thousands of repos and thousands of jobs in queued state. To fetch all jobs for an
// enterprise, we'd have to list all repos, and for each repo list all jobs currently in queued state. This is
// not desirable by any measure.
//
// One way to handle situations where garm comes up after a longer period of time, is to temporarily max out the
// min-idle-runner setting on pools, or at least raise it above 0. The idle runners will start to consume jobs, and
// as they do so, new idle runners will be spun up in their stead. New jobs will record in the DB as they come in,
// so those will trigger the creation of a runner. The jobs we don't know about will be dealt with by the idle runners.
// Once jobs are consumed, you can set min-idle-runners to 0 again.
func (r *basePoolManager) consumeQueuedJobs() error {
	queued, err := r.store.ListEntityJobsByStatus(r.ctx, r.entity.EntityType, r.entity.ID, params.JobStatusQueued)
	if err != nil {
		return errors.Wrap(err, "listing queued jobs")
	}

	poolsCache := poolsForTags{
		poolCacheType: r.entity.GetPoolBalancerType(),
	}

	slog.DebugContext(
		r.ctx, "found queued jobs",
		"job_count", len(queued))
	for _, job := range queued {
		if job.LockedBy != uuid.Nil && job.LockedBy.String() != r.ID() {
			// Job was handled by us or another entity.
			slog.DebugContext(
				r.ctx, "job is locked",
				"job_id", job.ID,
				"locking_entity", job.LockedBy.String())
			continue
		}

		if time.Since(job.UpdatedAt) < time.Second*time.Duration(r.controllerInfo.MinimumJobAgeBackoff) {
			// give the idle runners a chance to pick up the job.
			slog.DebugContext(
				r.ctx, "job backoff not reached", "backoff_interval", r.controllerInfo.MinimumJobAgeBackoff,
				"job_id", job.ID)
			continue
		}

		if time.Since(job.UpdatedAt) >= time.Minute*10 {
			// Job is still queued in our db, 10 minutes after a matching runner
			// was spawned. Unlock it and try again. A different job may have picked up
			// the runner.
			if err := r.store.UnlockJob(r.ctx, job.ID, r.ID()); err != nil {
				// nolint:golangci-lint,godox
				// TODO: Implament a cache? Should we return here?
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to unlock job",
					"job_id", job.ID)
				continue
			}
		}

		if job.LockedBy.String() == r.ID() {
			// nolint:golangci-lint,godox
			// Job is locked by us. We must have already attepted to create a runner for it. Skip.
			// TODO(gabriel-samfira): create an in-memory state of existing runners that we can easily
			// check for existing pending or idle runners. If we can't find any, attempt to allocate another
			// runner.
			slog.DebugContext(
				r.ctx, "job is locked by us",
				"job_id", job.ID)
			continue
		}

		poolRR, ok := poolsCache.Get(job.Labels)
		if !ok {
			potentialPools, err := r.store.FindPoolsMatchingAllTags(r.ctx, r.entity.EntityType, r.entity.ID, job.Labels)
			if err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "error finding pools matching labels")
				continue
			}
			poolRR = poolsCache.Add(job.Labels, potentialPools)
		}

		if poolRR.Len() == 0 {
			slog.DebugContext(r.ctx, "could not find pools with labels", "requested_labels", strings.Join(job.Labels, ","))
			continue
		}

		runnerCreated := false
		if err := r.store.LockJob(r.ctx, job.ID, r.ID()); err != nil {
			slog.With(slog.Any("error", err)).ErrorContext(
				r.ctx, "could not lock job",
				"job_id", job.ID)
			continue
		}

		jobLabels := []string{
			fmt.Sprintf("%s%d", jobLabelPrefix, job.ID),
		}
		for i := 0; i < poolRR.Len(); i++ {
			pool, err := poolRR.Next()
			if err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "could not find a pool to create a runner for job",
					"job_id", job.ID)
				break
			}

			slog.InfoContext(
				r.ctx, "attempting to create a runner in pool",
				"pool_id", pool.ID,
				"job_id", job.ID)
			if err := r.addRunnerToPool(pool, jobLabels); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "could not add runner to pool",
					"pool_id", pool.ID)
				continue
			}
			slog.DebugContext(r.ctx, "a new runner was added as a response to queued job",
				"pool_id", pool.ID,
				"job_id", job.ID)
			runnerCreated = true
			break
		}

		if !runnerCreated {
			slog.WarnContext(
				r.ctx, "could not create a runner for job; unlocking",
				"job_id", job.ID)
			if err := r.store.UnlockJob(r.ctx, job.ID, r.ID()); err != nil {
				slog.With(slog.Any("error", err)).ErrorContext(
					r.ctx, "failed to unlock job",
					"job_id", job.ID)
				return errors.Wrap(err, "unlocking job")
			}
		}
	}

	if err := r.store.DeleteCompletedJobs(r.ctx); err != nil {
		slog.With(slog.Any("error", err)).ErrorContext(
			r.ctx, "failed to delete completed jobs")
	}
	return nil
}

func (r *basePoolManager) UninstallWebhook(ctx context.Context) error {
	if r.controllerInfo.ControllerWebhookURL == "" {
		return errors.Wrap(runnerErrors.ErrBadRequest, "controller webhook url is empty")
	}

	allHooks, err := r.listHooks(ctx)
	if err != nil {
		return errors.Wrap(err, "listing hooks")
	}

	var controllerHookID int64
	var baseHook string
	trimmedBase := strings.TrimRight(r.controllerInfo.WebhookURL, "/")
	trimmedController := strings.TrimRight(r.controllerInfo.ControllerWebhookURL, "/")

	for _, hook := range allHooks {
		hookInfo := hookToParamsHookInfo(hook)
		info := strings.TrimRight(hookInfo.URL, "/")
		if strings.EqualFold(info, trimmedController) {
			controllerHookID = hook.GetID()
		}

		if strings.EqualFold(info, trimmedBase) {
			baseHook = hookInfo.URL
		}
	}

	if controllerHookID != 0 {
		_, err = r.ghcli.DeleteEntityHook(ctx, controllerHookID)
		if err != nil {
			return fmt.Errorf("deleting hook: %w", err)
		}
		return nil
	}

	if baseHook != "" {
		return runnerErrors.NewBadRequestError("base hook found (%s) and must be deleted manually", baseHook)
	}

	return nil
}

func (r *basePoolManager) InstallHook(ctx context.Context, req *github.Hook) (params.HookInfo, error) {
	allHooks, err := r.listHooks(ctx)
	if err != nil {
		return params.HookInfo{}, errors.Wrap(err, "listing hooks")
	}

	if err := validateHookRequest(r.controllerInfo.ControllerID.String(), r.controllerInfo.WebhookURL, allHooks, req); err != nil {
		return params.HookInfo{}, errors.Wrap(err, "validating hook request")
	}

	hook, err := r.ghcli.CreateEntityHook(ctx, req)
	if err != nil {
		return params.HookInfo{}, errors.Wrap(err, "creating entity hook")
	}

	if _, err := r.ghcli.PingEntityHook(ctx, hook.GetID()); err != nil {
		slog.With(slog.Any("error", err)).ErrorContext(
			ctx, "failed to ping hook",
			"hook_id", hook.GetID(),
			"entity", r.entity)
	}

	return hookToParamsHookInfo(hook), nil
}

func (r *basePoolManager) InstallWebhook(ctx context.Context, param params.InstallWebhookParams) (params.HookInfo, error) {
	if r.controllerInfo.ControllerWebhookURL == "" {
		return params.HookInfo{}, errors.Wrap(runnerErrors.ErrBadRequest, "controller webhook url is empty")
	}

	insecureSSL := "0"
	if param.InsecureSSL {
		insecureSSL = "1"
	}
	req := &github.Hook{
		Active: github.Bool(true),
		Config: map[string]interface{}{
			"url":          r.controllerInfo.ControllerWebhookURL,
			"content_type": "json",
			"insecure_ssl": insecureSSL,
			"secret":       r.WebhookSecret(),
		},
		Events: []string{
			"workflow_job",
		},
	}

	return r.InstallHook(ctx, req)
}

func (r *basePoolManager) ValidateOwner(job params.WorkflowJob) error {
	switch r.entity.EntityType {
	case params.GithubEntityTypeRepository:
		if !strings.EqualFold(job.Repository.Name, r.entity.Name) || !strings.EqualFold(job.Repository.Owner.Login, r.entity.Owner) {
			return runnerErrors.NewBadRequestError("job not meant for this pool manager")
		}
	case params.GithubEntityTypeOrganization:
		if !strings.EqualFold(job.Organization.Login, r.entity.Owner) {
			return runnerErrors.NewBadRequestError("job not meant for this pool manager")
		}
	case params.GithubEntityTypeEnterprise:
		if !strings.EqualFold(job.Enterprise.Slug, r.entity.Owner) {
			return runnerErrors.NewBadRequestError("job not meant for this pool manager")
		}
	default:
		return runnerErrors.NewBadRequestError("unknown entity type")
	}

	return nil
}

func (r *basePoolManager) GithubRunnerRegistrationToken() (string, error) {
	tk, ghResp, err := r.ghcli.CreateEntityRegistrationToken(r.ctx)
	if err != nil {
		if ghResp != nil && ghResp.StatusCode == http.StatusUnauthorized {
			return "", errors.Wrap(runnerErrors.ErrUnauthorized, "fetching token")
		}
		return "", errors.Wrap(err, "creating runner token")
	}
	return *tk.Token, nil
}

func (r *basePoolManager) FetchTools() ([]commonParams.RunnerApplicationDownload, error) {
	tools, ghResp, err := r.ghcli.ListEntityRunnerApplicationDownloads(r.ctx)
	if err != nil {
		if ghResp != nil && ghResp.StatusCode == http.StatusUnauthorized {
			return nil, errors.Wrap(runnerErrors.ErrUnauthorized, "fetching tools")
		}
		return nil, errors.Wrap(err, "fetching runner tools")
	}

	ret := []commonParams.RunnerApplicationDownload{}
	for _, tool := range tools {
		if tool == nil {
			continue
		}
		ret = append(ret, commonParams.RunnerApplicationDownload(*tool))
	}
	return ret, nil
}

func (r *basePoolManager) GetGithubRunners() ([]*github.Runner, error) {
	opts := github.ListOptions{
		PerPage: 100,
	}
	var allRunners []*github.Runner

	for {
		runners, ghResp, err := r.ghcli.ListEntityRunners(r.ctx, &opts)
		if err != nil {
			if ghResp != nil && ghResp.StatusCode == http.StatusUnauthorized {
				return nil, errors.Wrap(runnerErrors.ErrUnauthorized, "fetching runners")
			}
			return nil, errors.Wrap(err, "fetching runners")
		}
		allRunners = append(allRunners, runners.Runners...)
		if ghResp.NextPage == 0 {
			break
		}
		opts.Page = ghResp.NextPage
	}

	return allRunners, nil
}

func (r *basePoolManager) GithubURL() string {
	switch r.entity.EntityType {
	case params.GithubEntityTypeRepository:
		return fmt.Sprintf("%s/%s/%s", r.entity.Credentials.BaseURL, r.entity.Owner, r.entity.Name)
	case params.GithubEntityTypeOrganization:
		return fmt.Sprintf("%s/%s", r.entity.Credentials.BaseURL, r.entity.Owner)
	case params.GithubEntityTypeEnterprise:
		return fmt.Sprintf("%s/enterprises/%s", r.entity.Credentials.BaseURL, r.entity.Owner)
	}
	return ""
}

func (r *basePoolManager) GetWebhookInfo(ctx context.Context) (params.HookInfo, error) {
	allHooks, err := r.listHooks(ctx)
	if err != nil {
		return params.HookInfo{}, errors.Wrap(err, "listing hooks")
	}
	trimmedBase := strings.TrimRight(r.controllerInfo.WebhookURL, "/")
	trimmedController := strings.TrimRight(r.controllerInfo.ControllerWebhookURL, "/")

	var controllerHookInfo *params.HookInfo
	var baseHookInfo *params.HookInfo

	for _, hook := range allHooks {
		hookInfo := hookToParamsHookInfo(hook)
		info := strings.TrimRight(hookInfo.URL, "/")
		if strings.EqualFold(info, trimmedController) {
			controllerHookInfo = &hookInfo
			break
		}
		if strings.EqualFold(info, trimmedBase) {
			baseHookInfo = &hookInfo
		}
	}

	// Return the controller hook info if available.
	if controllerHookInfo != nil {
		return *controllerHookInfo, nil
	}

	// Fall back to base hook info if defined.
	if baseHookInfo != nil {
		return *baseHookInfo, nil
	}

	return params.HookInfo{}, runnerErrors.NewNotFoundError("hook not found")
}

func (r *basePoolManager) RootCABundle() (params.CertificateBundle, error) {
	return r.entity.Credentials.RootCertificateBundle()
}