added buildkitd sidecar to act runner

internal/spec/spec.go

@@ -163,15 +163,45 @@ func GetPodSpec(gitHubScope GitHubScopeDetails, bootstrapParams params.Bootstrap
 				Env:             envs,
 				VolumeMounts: []corev1.VolumeMount{
 					{
-						Name:      "runner-dir",
+						Name:      "buildkitd-deamon",
-						MountPath: "/runner",
+						MountPath: "/run/user/1000/buildkit",
+					},
+				},
+			},
+			{
+				Name:  "buildkitd",
+				Image: "moby/buildkit:buildx-stable-1-rootless",
+				Args: []string{
+					"--allow-insecure-entitlement=network.host",
+					"--oci-worker-no-process-sandbox",
+				},
+				ImagePullPolicy: corev1.PullIfNotPresent,
+				ReadinessProbe: &corev1.Probe{
+					ProbeHandler: corev1.ProbeHandler{
+						Exec: &corev1.ExecAction{
+							Command: []string{
+								"buildctl",
+								"debug",
+								"workers",
+							},
+						},
+					},
+					FailureThreshold: 3,
+					PeriodSeconds:    10,
+					SuccessThreshold: 1,
+					TimeoutSeconds:   1,
+				},
+				VolumeMounts: []corev1.VolumeMount{
+					{
+						Name:      "buildkitd-deamon",
+						MountPath: "/run/user/1000/buildkit",
 					},
 				},
 			},
 		},
 		Volumes: []corev1.Volume{
 			{
-				Name: "runner-dir",
+				Name: "buildkitd-deamon",
 				VolumeSource: corev1.VolumeSource{
 					EmptyDir: &corev1.EmptyDirVolumeSource{},
 				},