Lock Check

action.yml

@@ -30,7 +30,7 @@ inputs:
     required: false
     default: "true"
   mode:
-    description: 'The mode to use "lock" or "unlock". If not provided, the default mode assumes the workflow is not headless and triggered by a comment on a pull request - Example: .lock / .unlock'
+    description: 'The mode to use "lock", "unlock", or "check". If not provided, the default mode assumes the workflow is not headless and triggered by a comment on a pull request - Example: .lock / .unlock'
     required: false
   reason:
     description: Reason for claiming the deployment lock for this repository
@@ -42,6 +42,8 @@ outputs:
     description: The comment id which triggered this deployment (if it was not headless)
   headless:
     description: 'The string "true" if the run was headless, otherwise the string "false" - Headless in this context would be if the "mode" was set and the Action was not invoked by a comment on a pull request'
+  locked:
+    description: 'If the mode is set to "check", this output will be "true" if a lock exists, otherwise "false"'
 runs:
   using: "node16"
   main: "dist/index.js"

src/functions/check.js

@@ -0,0 +1,60 @@
+import * as core from '@actions/core'
+
+// Constants for the lock file
+const LOCK_BRANCH = 'branch-deploy-lock'
+const LOCK_FILE = 'lock.json'
+
+// Helper function for checking if a deployment lock exists
+// :param octokit: The octokit client
+// :param context: The GitHub Actions event context
+// :returns: true if the lock exists, false if it does not
+export async function check(octokit, context) {
+  // Check if the lock branch already exists
+  try {
+    await octokit.rest.repos.getBranch({
+      ...context.repo,
+      branch: LOCK_BRANCH
+    })
+  } catch (error) {
+    // If the lock file doesn't exist, return
+    if (error.status === 404) {
+      core.saveState('locked', 'false')
+      return false
+    }
+  }
+
+  // If the lock branch exists, check if a lock file exists
+  try {
+    // Get the lock file contents
+    const response = await octokit.rest.repos.getContent({
+      ...context.repo,
+      path: LOCK_FILE,
+      ref: LOCK_BRANCH
+    })
+
+    // Decode the file contents to json
+    const lockData = JSON.parse(
+      Buffer.from(response.data.content, 'base64').toString()
+    )
+
+    // If the lock file exists, and can be decoded, return true
+    if (lockData !== null && lockData !== undefined) {
+      // Set locked to true if the lock file exists
+      core.saveState('locked', 'true')
+      return true
+    }
+
+    // If we get here, the lock file may exist but it cannot be decoded
+    core.saveState('locked', 'false')
+    return false
+  } catch (error) {
+    // If the lock file doesn't exist, return false
+    if (error.status === 404) {
+      core.saveState('locked', 'false')
+      return false
+    }
+
+    // If some other error occurred, throw it
+    throw new Error(error)
+  }
+}

src/main.js

@@ -5,6 +5,7 @@ import {actionStatus} from './functions/action-status'
 import {validPermissions} from './functions/valid-permissions'
 import {lock} from './functions/lock'
 import {unlock} from './functions/unlock'
+import {check} from './functions/check'
 import {timeDiff} from './functions/time-diff'
 import * as github from '@actions/github'
 import {context} from '@actions/github'
@@ -43,6 +44,9 @@ export async function run() {
     } else if (lock_mode === 'unlock') {
       await unlock(octokit, context, null, true)
       return 'success - headless'
+    } else if (lock_mode === 'check') {
+      await check(octokit, context)
+      return 'success - headless'
     }
 
     // Get the body of the IssueOps command