Use auto shutdown hook instead of explicit shutdown

.github/workflows/manual_test.yml

@@ -18,7 +18,7 @@ on:
         description: Service account of the VM, defaults to default compute service account.
         required: false
       shutdown_timeout:
-        description: "Grace period for the `stop` command, in seconds."
+        description: "Shutdown grace period (in seconds)."
         default: 30
         required: true
       no_external_address:
@@ -50,14 +50,10 @@ jobs:
           image_family: ubuntu-2004-lts
           no_external_address: ${{ inputs.no_external_address }}
           actions_preinstalled: ${{ inputs.actions_preinstalled }}
+          shutdown_timeout: ${{ inputs.shutdown_timeout }}
 
   test:
     needs: create-runner
     runs-on: ${{ needs.create-runner.outputs.label }}
     steps:
       - run: echo "This runs on the GCE runner VM"
-      - uses: related-sciences/gce-github-runner@main
-        with:
-          command: stop
-          shutdown_timeout: ${{ inputs.shutdown_timeout }}
-        if: always()

.github/workflows/test.yml

@@ -30,7 +30,3 @@ jobs:
     runs-on: ${{ needs.create-runner.outputs.label }}
     steps:
       - run: echo "This runs on the GCE runner VM"
-      - uses: related-sciences/gce-github-runner@main
-        with:
-          command: stop
-        if: always()

README.md

@@ -28,14 +28,11 @@ jobs:
     runs-on: ${{ needs.create-runner.outputs.label }}
     steps:
       - run: echo "This runs on the GCE VM"
-      - uses: related-sciences/gce-github-runner@v0.7
-        with:
-          command: stop
-        if: always()
 ```
 
  * `create-runner` creates the GCE VM and registers the runner with unique label
- * `test` uses the runner, and destroys it as the last step
+ * `test` uses the runner
+ * the runner VM will be automatically shut down after the workflow via [self-hosted runner hook](https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/running-scripts-before-or-after-a-job)
 
 ## Inputs
 

action.sh

@@ -193,32 +193,43 @@ function start_vm {
   echo "The new GCE VM will be ${VM_ID}"
 
   startup_script="
-# Create a systemd service in charge of shutting down the machine once the workflow has finished
-cat > /etc/systemd/system/shutdown.sh << EOF
-#!/bin/sh
-sleep ${shutdown_timeout}
-gcloud compute instances delete $VM_ID --zone=$machine_zone --quiet
-EOF
-cat > /etc/systemd/system/shutdown.service << EOF1
-[Unit]
-Description=Shutdown service
-[Service]
-ExecStart=/etc/systemd/system/shutdown.sh
-[Install]
-WantedBy=multi-user.target
-EOF1
-chmod +x /etc/systemd/system/shutdown.sh
-systemctl daemon-reload
-systemctl enable shutdown.service
+	# Create a systemd service in charge of shutting down the machine once the workflow has finished
+	cat <<-EOF > /etc/systemd/system/shutdown.sh
+	#!/bin/sh
+	sleep ${shutdown_timeout}
+	gcloud compute instances delete $VM_ID --zone=$machine_zone --quiet
+	EOF
 
-    gcloud compute instances add-labels ${VM_ID} --zone=${machine_zone} --labels=gh_ready=0 && \\
-    RUNNER_ALLOW_RUNASROOT=1 ./config.sh --url https://github.com/${GITHUB_REPOSITORY} --token ${RUNNER_TOKEN} --labels ${VM_ID} --unattended ${ephemeral_flag} --disableupdate && \\
-    ./svc.sh install && \\
-    ./svc.sh start && \\
-    gcloud compute instances add-labels ${VM_ID} --zone=${machine_zone} --labels=gh_ready=1
-    # 3 days represents the max workflow runtime. This will shutdown the instance if everything else fails.
-    nohup sh -c \"sleep 3d && gcloud --quiet compute instances delete ${VM_ID} --zone=${machine_zone}\" > /dev/null &
-    "
+	cat <<-EOF > /etc/systemd/system/shutdown.service
+	[Unit]
+	Description=Shutdown service
+	[Service]
+	ExecStart=/etc/systemd/system/shutdown.sh
+	[Install]
+	WantedBy=multi-user.target
+	EOF
+
+	chmod +x /etc/systemd/system/shutdown.sh
+	systemctl daemon-reload
+	systemctl enable shutdown.service
+
+	cat <<-EOF > /usr/bin/gce_runner_shutdown.sh
+	#!/bin/sh
+	echo \"✅ Self deleting $VM_ID in ${machine_zone} in ${shutdown_timeout} seconds ...\"
+	# We tear down the machine by starting the systemd service that was registered by the startup script
+	systemctl start shutdown.service
+	EOF
+
+	# See: https://docs.github.com/en/actions/hosting-your-own-runners/managing-self-hosted-runners/running-scripts-before-or-after-a-job
+	echo "ACTIONS_RUNNER_HOOK_JOB_COMPLETED=/usr/bin/gce_runner_shutdown.sh" >.env
+	gcloud compute instances add-labels ${VM_ID} --zone=${machine_zone} --labels=gh_ready=0 && \\
+	RUNNER_ALLOW_RUNASROOT=1 ./config.sh --url https://github.com/${GITHUB_REPOSITORY} --token ${RUNNER_TOKEN} --labels ${VM_ID} --unattended ${ephemeral_flag} --disableupdate && \\
+	./svc.sh install && \\
+	./svc.sh start && \\
+	gcloud compute instances add-labels ${VM_ID} --zone=${machine_zone} --labels=gh_ready=1
+	# 3 days represents the max workflow runtime. This will shutdown the instance if everything else fails.
+	nohup sh -c \"sleep 3d && gcloud --quiet compute instances delete ${VM_ID} --zone=${machine_zone}\" > /dev/null &
+  "
 
   if $actions_preinstalled ; then
     echo "✅ Startup script won't install GitHub Actions (pre-installed)"
@@ -283,30 +294,13 @@ systemctl enable shutdown.service
   fi
 }
 
-function stop_vm {
-  # NOTE: this function runs on the GCE VM
-  echo "Stopping GCE VM ..."
-  # NOTE: it would be nice to gracefully shut down the runner, but we actually don't need
-  #       to do that. VM shutdown will disconnect the runner, and GH will unregister it
-  #       in 30 days
-  # TODO: RUNNER_ALLOW_RUNASROOT=1 /actions-runner/config.sh remove --token $TOKEN
-  NAME=$(curl -S -s -X GET http://metadata.google.internal/computeMetadata/v1/instance/name -H 'Metadata-Flavor: Google')
-  ZONE=$(curl -S -s -X GET http://metadata.google.internal/computeMetadata/v1/instance/zone -H 'Metadata-Flavor: Google')
-  echo "✅ Self deleting $NAME in $ZONE in ${shutdown_timeout} seconds ..."
-  # We tear down the machine by starting the systemd service that was registered by the startup script
-  systemctl start shutdown.service
-}
-
 safety_on
 case "$command" in
   start)
     start_vm
     ;;
-  stop)
-    stop_vm
-    ;;
   *)
-    echo "Invalid command: \`${command}\`, valid values: start|stop" >&2
+    echo "Invalid command: \`${command}\`, valid values: start" >&2
     usage
     exit 1
     ;;

action.yml

@@ -7,10 +7,6 @@ branding:
   icon: triangle
   color: purple
 inputs:
-  command:
-    description: "`start` or `stop` of the runner"
-    default: start
-    required: true
   token:
     description: >-
       GitHub auth token, needs `repo`/`public_repo` scope: https://docs.github.com/en/rest/reference/actions#self-hosted-runners.
@@ -26,7 +22,7 @@ inputs:
     required: false
   runner_ver:
     description: Version of the GitHub Runner.
-    default: "2.303.0"
+    default: "2.304.0"
     required: true
   machine_zone:
     description: GCE zone
@@ -87,7 +83,7 @@ inputs:
     default: cloud-platform
     required: true
   shutdown_timeout:
-    description: "Grace period for the `stop` command, in seconds."
+    description: "Shutdown grace period (in seconds)."
     default: 30
     required: true
   actions_preinstalled:
@@ -115,7 +111,7 @@ runs:
     - id: gce-github-runner-script
       run: >
         ${{ github.action_path }}/action.sh
-        --command=${{ inputs.command }}
+        --command=start
         --token=${{ inputs.token }}
         --project_id=${{ inputs.project_id }}
         --service_account_key='${{ inputs.service_account_key }}'