---
title: "Edge Developer Platform: Forgejo Integration & GARM Extension"
date: "2025-11-19"
description: "Technical report on the implementation of the Edge Developer Platform (EDP) using Forgejo, featuring GARM integration for ephemeral CI/CD runners and upstream open-source contributions."
tags: ["Forgejo", "GARM", "CI/CD", "OSS", "Architecture", "Project Report"]
categories: ["Workpackage Results"]
mermaid: true
---

## 1. Project Identity & Governance

### 1.1 Project Scope

The internal service is officially designated as the **Edge Developer Platform (EDP)**. It is hosted at **[edp.buildth.ing](https://edp.buildth.ing)**. The domain selection followed a democratic team process to establish a unique identity distinct from standard corporate naming conventions.

**Access Model:**
The platform operates on a hybrid visibility model:

* **Public Access:** The [`DEVFW-CICD`](https://edp.buildth.ing/DevFW-CICD) organization is publicly accessible, fostering transparency.
* **Private Access:** Sensitive development occurs in restricted organizations (e.g., [`DEVFW`](https://edp.buildth.ing/DevFW)).
* **User Base:** Primary users include the internal development team, with friendly user access granted to the IPCEI team and MMS BT.

### 1.2 Strategic Selection & Governance

The decision to utilize **[Forgejo](https://forgejo.org/)** as the core self-hosted Git service was driven by specific strategic requirements:

* **EU-Based Stewardship:** Forgejo is stewarded by **[Codeberg e.V.](https://docs.codeberg.org/getting-started/what-is-codeberg/)**, a non-profit organization based in Berlin, Germany. This alignment ensures compliance with GDPR and data sovereignty requirements, placing governance under EU jurisdiction rather than US tech entities.
* **License Protection (GPL v3+):** Unlike "Open Core" models, Forgejo uses a copyleft license. This legally protects our custom extensions (such as GARM support) from being appropriated into proprietary software, ensuring the ecosystem remains open.
* **Open Source Strategy:** The platform aligns with the "Public Money, Public Code" philosophy, mandating that funded developments are returned to the community.

---

## 2. Technical Architecture & Deployment

### 2.1 Infrastructure Stack

The platform is hosted on the **Open Telekom Cloud (OTC)**. The infrastructure adheres to Infrastructure-as-Code (IaC) principles.

* **Deployment Method:** The official Forgejo Helm Chart is deployed via **ArgoCD**.
* **Infrastructure Provisioning:** **Terraform** is used to provision all underlying OTC services, including:
  * **Container Orchestration**: CCE (Cloud Container Engine): Kubernetes
  * **Database:** RDS (Distributed Cache Service): PostgreSQL
  * **Caching:** DCS (Distributed Cache Service): Redis
  * **Object Storage:** OBS (Object Storage Service, S3-compatible): for user data (avatars, attachments).
  * **Search:** CSS (Cloud Search Service): Elasticsearch

### 2.2 The "Self-Replicating" Pipeline

A key architectural feature is the ability of the platform to maintain itself. A Forgejo Action can trigger the deployment script, which runs Terraform and syncs ArgoCD, effectively allowing "Forgejo to create/update Forgejo."

```mermaid
graph TD
    subgraph "Open Telekom Cloud (OTC)"
        subgraph "Control Plane"
            Dev[DevOps Engineer] -->|Triggers| Pipeline[Deployment Pipeline]
            Pipeline -->|Executes| TF[Terraform]
        end
        
        subgraph "Provisioned Infrastructure"
            TF -->|Provisions| CCE[(CCE K8s Cluster)]
            TF -->|Provisions| RDS[(RDS PostgreSQL)]
            TF -->|Provisions| Redis[(DCS Redis)]
            TF -->|Provisions| S3[(OBS S3 Bucket)]
            TF -->|Provisions| CSS[(CSS Elasticsearch)]
        end
        
        subgraph "Application Layer (on CCE K8s)"
            Pipeline -->|Helm Chart| Argo[ArgoCD]
            Argo -->|Deploys| ForgejoApp[Forgejo]
        end
        
        CCE -- Runs --> Argo
        CCE -- Runs --> ForgejoApp
        ForgejoApp -->|Connects| RDS
        ForgejoApp -->|Connects| Redis
        ForgejoApp -->|Connects| S3
        ForgejoApp -->|Connects| CSS
    end
```

### 2.3 Migration History

The initial environment was a manual setup on the Open Sovereign Cloud (OSC). Once the automation stack (Terraform/ArgoCD) was matured, the platform was migrated to the current OTC environment.

---

## 3. Application Extensions & GARM Integration

### 3.1 Core Functionality

Beyond standard Git versioning, the platform utilizes:

* **Releases:** Hosting binaries for software distribution (e.g., Edge Connect CLI).
* **CI/CD:** Extensive pipeline usage for build, test, and deployment automation.
* **Note on Issues:** While initially used, issue tracking was migrated to JIRA to align with the broader IPCEI program standards.

### 3.2 GARM (Git-based Actions Runner Manager)

The primary technical innovation was the integration of **[GARM](https://github.com/cloudbase/garm)** to enable ephemeral, scalable runners. This required extending Forgejo's capabilities to support GitHub-compatible runner registration and webhook events.

**Workflow Architecture:**

1. **Event:** A workflow event occurs in Forgejo.
2. **Trigger:** A webhook notifies GARM.
3. **Provisioning:** GARM spins up a fresh, ephemeral runner.
4. **Execution:** The runner registers via the API, executes the job, and is terminated immediately after, ensuring a clean build environment.

```mermaid
sequenceDiagram
    participant User
    participant Forgejo
    participant GARM
    participant Runner as Ephemeral Runner
    
    User->>Forgejo: Push Code / Trigger Event
    Forgejo->>GARM: Webhook Event (Workflow Dispatch)
    GARM->>Forgejo: Register Runner (via API)
    GARM->>Runner: Spin up Instance
    Runner->>Forgejo: Request Job
    Forgejo->>Runner: Send Job Payload
    Runner->>Runner: Execute Steps
    Runner->>Forgejo: Report Status
    GARM->>Runner: Terminate (Ephemeral)
```

---

## 4. Development Methodology & Contributions

### 4.1 Workflow

* **Branching Strategy:** Trunk-based development was utilized to ensure rapid integration.
* **Collaboration:** The team adopted **Mob Programming**. This practice proved essential for knowledge sharing and onboarding junior developers, creating a resilient and high-intensity learning environment.
* **Versions:** The platform evolved from Forgejo v7/8 to the current v11.0.3-edp1. An upgrade is pending to leverage the latest upstream GARM features.

### 4.2 Open Source Contributions

We actively contributed our extensions back to the upstream Forgejo project on **[Codeberg.org](https://codeberg.org/)**.

**Key Pull Requests:**

* **API Compatibility:** Added GitHub-compatible endpoints for runner registration.
  * [PR #9409: Feat: Add endpoints for GARM](https://codeberg.org/forgejo/forgejo/pulls/9409)
* **Webhook Support:** Implemented webhook triggers for workflow events.
  * [PR #9803: Feat: Add webhook support for workflow events](https://codeberg.org/forgejo/forgejo/pulls/9803)
* **Ephemeral Runners:** Added support for runners that terminate after a single job.
  * [PR #9962: Feat: Support for ephemeral runners](https://codeberg.org/forgejo/forgejo/pulls/9962)

**Artifact Caching (Pull-Through Proxy):**
We implemented a feature allowing Forgejo to act as a pull-through proxy for remote container registries, optimizing bandwidth and build speeds.

* [Source Code Branch: refactor-remote-registry-client](https://edp.buildth.ing/DevFW/edp-forgejo/src/branch/refactor-remote-registry-client)

---

## 5. Key Performance Indicators (KPIs)

These KPIs measure the effectiveness of the Forgejo setup and quantify our strategic commitment to the Forgejo community.

| KPI | Description | Target / Benchmark |
| :--- | :--- | :--- |
| **Deployment Frequency** | Frequency of successful pipeline executions. | High (Daily/On-demand) |
| **Artifact Cache Hit Rate** | Percentage of build requests served by the local Forgejo proxy. | > 90% (Reduced external traffic) |
| **Upstream Contribution** | Percentage of GARM-related features contributed back to Codeberg. | 100% (No vendor lock-in) |
| **PR Resolution Time** | Average time for upstream community review and merge. | < 14 days (Healthy collaboration) |