Add workflow for maintaining floating tags (#234)

Author: sethvargo

.github/workflows/tag.yml

@@ -0,0 +1,58 @@
+name: 'tag'
+
+on:
+  push:
+    tags:
+    # match vx.y and v x.y.z.w... but not vx
+    - 'v[0-9]+.*'
+
+jobs:
+  # pointer parses the incoming tag value and updates the "vX" pointer to the
+  # same SHA as this tag.
+  pointer:
+    name: 'pointer'
+    runs-on: 'ubuntu-latest'
+    steps:
+    - uses: 'actions/github-script@v5'
+      with:
+        script: |-
+          const tag = process.env.GITHUB_REF_NAME;
+          if(!tag) {
+            core.setFailed(`Missing tag!`)
+            return
+          }
+          core.info(`Using tag "${tag}"`)
+
+          const matches = tag.match(/(v[0-9]+).*/)
+          if(!matches || matches.length < 2) {
+            core.setFailed(`Invalid tag "${tag}"`)
+            return
+          }
+          const major = matches[1];
+          core.info(`Matched to major tag "${major}"`)
+
+          // Try to update the ref first. If that fails, it probably does not
+          // exist yet, and we should create it.
+          try {
+            await github.rest.git.updateRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `tags/${major}`,
+              sha: context.sha,
+              force: true,
+            })
+
+            core.info(`Updated "${major}" to "${tag}" (${context.sha})`)
+          } catch {
+            core.warning(`Failed to update "${major}" tag (it may not `+
+              `exist). Trying to create "${major}" now.`)
+
+            await github.rest.git.createRef({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              ref: `refs/tags/${major}`,
+              sha: context.sha,
+            })
+
+            core.info(`Created "${major}" at "${tag}" (${context.sha})`)
+          }

README.md

@@ -45,15 +45,15 @@ jobs:
         workload_identity_provider: 'projects/123456789/locations/global/workloadIdentityPools/my-pool/providers/my-provider'
         service_account: 'my-service-account@my-project.iam.gserviceaccount.com'
 
-    - id: deploy
-      uses: google-github-actions/deploy-cloud-functions@v0.7.0
+    - id: 'deploy'
+      uses: 'google-github-actions/deploy-cloud-functions@v0'
       with:
-        name: my-function
-        runtime: nodejs10
+        name: 'my-function'
+        runtime: 'nodejs12'
 
     # Example of using the output
-    - id: test
-      run: curl "${{ steps.deploy.outputs.url }}"
+    - id: 'test'
+      run: 'curl "${{ steps.deploy.outputs.url }}"'
 ```
 
 ## Inputs
@@ -221,19 +221,19 @@ jobs:
       id-token: 'write'
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: 'actions/checkout@v2'
 
-    - id: auth
-      uses: google-github-actions/auth@v0
+    - id: 'auth'
+      uses: 'google-github-actions/auth@v0'
       with:
         workload_identity_provider: 'projects/123456789/locations/global/workloadIdentityPools/my-pool/providers/my-provider'
         service_account: 'my-service-account@my-project.iam.gserviceaccount.com'
 
-    - id: deploy
-      uses: google-github-actions/deploy-cloud-functions@v0.7.0
+    - id: 'deploy'
+      uses: 'google-github-actions/deploy-cloud-functions@v0'
       with:
-        name: my-function
-        runtime: nodejs10
+        name: 'my-function'
+        runtime: 'nodejs12'
 ```
 
 #### Authenticating via Service Account Key JSON
@@ -242,18 +242,18 @@ jobs:
 jobs:
   job_id:
     steps:
-    - uses: actions/checkout@v2
+    - uses: 'actions/checkout@v2'
 
-    - id: auth
-      uses: google-github-actions/auth@v0
+    - id: 'auth'
+      uses: 'google-github-actions/auth@v0'
       with:
-        credentials_json: ${{ secrets.gcp_credentials }}
+        credentials_json: '${{ secrets.gcp_credentials }}'
 
-    - id: deploy
-      uses: google-github-actions/deploy-cloud-functions@v0.7.0
+    - id: 'deploy'
+      uses: 'google-github-actions/deploy-cloud-functions@v0'
       with:
-        name: my-function
-        runtime: nodejs10
+        name: 'my-function'
+        runtime: 'nodejs12'
 ```
 
 ### Via Application Default Credentials
@@ -267,13 +267,13 @@ only works using a custom runner hosted on GCP.**
 jobs:
   job_id:
     steps:
-    - uses: actions/checkout@v2
+    - uses: 'actions/checkout@v2'
 
-    - id: Deploy
-      uses: google-github-actions/deploy-cloud-functions@v0.7.0
+    - id: 'deploy'
+      uses: 'google-github-actions/deploy-cloud-functions@v0'
       with:
-        name: my-function
-        runtime: nodejs10
+        name: 'my-function'
+        runtime: 'nodejs12'
 ```
 
 The action will automatically detect and use the Application Default