From 312c174db1c3052ef879a24e99b0e8f085f5fead Mon Sep 17 00:00:00 2001
From: Yaraslau Kurmyza <yarik@mozilla.com>
Date: Mon, 29 Apr 2024 12:35:14 +0200
Subject: [PATCH] feat(github): Ignore missing task groups on auto-cancel

---
 changelog/issue-6761.md               |  7 ++++
 services/github/src/handlers/index.js | 13 ++++++--
 services/github/test/handler_test.js  | 47 +++++++++++++++++++++++++++
 3 files changed, 65 insertions(+), 2 deletions(-)
 create mode 100644 changelog/issue-6761.md

diff --git a/changelog/issue-6761.md b/changelog/issue-6761.md
new file mode 100644
index 00000000000..cd065dddf42
--- /dev/null
+++ b/changelog/issue-6761.md
@@ -0,0 +1,7 @@
+audience: developers
+level: patch
+reference: issue 6984
+---
+
+Github auto-cancel gracefully ignores missing task groups and doesn't log errors in github comments.
+This can happen when decision task failed on previous runs.
diff --git a/services/github/src/handlers/index.js b/services/github/src/handlers/index.js
index 6350e2cec13..f8a601a830f 100644
--- a/services/github/src/handlers/index.js
+++ b/services/github/src/handlers/index.js
@@ -308,8 +308,17 @@ class Handlers {
         const limitedQueueClient = this.queueClient.use({ authorizedScopes: scopes });
 
         debug(`Found running task groups: ${taskGroupIds.join(', ')}. Sealing and cancelling`);
-        await Promise.all(taskGroupIds.map(taskGroupId => limitedQueueClient.sealTaskGroup(taskGroupId)));
-        await Promise.all(taskGroupIds.map(taskGroupId => limitedQueueClient.cancelTaskGroup(taskGroupId)));
+        try {
+          await Promise.all(taskGroupIds.map(taskGroupId => limitedQueueClient.sealTaskGroup(taskGroupId)));
+          await Promise.all(taskGroupIds.map(taskGroupId => limitedQueueClient.cancelTaskGroup(taskGroupId)));
+        } catch (queueErr) {
+          if (queueErr.errorCode !== 'ResourceNotFound' || queueErr.statusCode !== 404) {
+            throw queueErr;
+          }
+          // we can ignore task groups that were not yet created on queue side, and simply mark as cancelled in the db
+          this.monitor.reportError(`Task group not found in queue: ${queueErr.message} while canceling`);
+        }
+
         await Promise.all(taskGroupIds.map(taskGroupId => this.context.db.fns.set_github_build_state(
           taskGroupId, GITHUB_BUILD_STATES.CANCELLED,
         )));
diff --git a/services/github/test/handler_test.js b/services/github/test/handler_test.js
index baf529080f3..aa919090b91 100644
--- a/services/github/test/handler_test.js
+++ b/services/github/test/handler_test.js
@@ -340,7 +340,54 @@ helper.secrets.mockSuite(testing.suiteName(), [], function (mock, skipping) {
         ({ Type, Severity, Fields }) => Type === 'monitor.error' && Severity === LEVELS.err && Fields.message.includes('sealTaskGroup error: missing scopes'),
       ));
       monitor.manager.reset();
+    });
+
+    test('non-existent task groups queue.sealTask/cancelTaskGroup group are ignored', async function () {
+      const err = new Error('ResourceNotFound');
+      err.errorCode = 'ResourceNotFound';
+      err.statusCode = 404;
+      handlers.queueClient = new taskcluster.Queue({
+        rootUrl: 'https://tc.example.com',
+        fake: {
+          sealTaskGroup: async (taskGroupId) => {
+            err.method = 'sealTaskGroup';
+            throw err;
+          },
+          cancelTaskGroup: async (taskGroupId) => {
+            err.method = 'cancelTaskGroup';
+            throw err;
+          },
+        },
+      });
+
+      await addBuild({ state: 'pending', taskGroupId: 'aa', pullNumber: 1, eventType: 'pull_request.opened' });
+      await addBuild({ state: 'pending', taskGroupId: 'bb', pullNumber: 1, eventType: 'pull_request.synchronize' });
+
+      const instGithub = github.inst(5828);
 
+      await handlers.realCancelPreviousTaskGroups({
+        instGithub,
+        debug: sinon.stub(),
+        newBuild: {
+          sha: COMMIT_SHA, organization: 'TaskclusterRobot', repository: 'hooks-testing',
+          pull_number: 1, event_type: 'pull_request.synchronize',
+        },
+      });
+      assert(instGithub.issues.createComment.notCalled);
+
+      const monitor = await helper.load('monitor');
+      assert(monitor.manager.messages.some(
+        ({ Type, Severity, Fields }) => Type === 'monitor.error' && Severity === LEVELS.err && Fields.message.includes('Task group not found in queue'),
+      ));
+      monitor.manager.reset();
+
+      // builds should still be cancelled in db
+      const [[buildA], [buildB]] = await Promise.all([
+        helper.db.fns.get_github_build_pr('aa'),
+        helper.db.fns.get_github_build_pr('bb'),
+      ]);
+      assert.equal(buildA.state, 'cancelled');
+      assert.equal(buildB.state, 'cancelled');
     });
 
     test('calls queue.sealTaskGroup/cancelTaskGroup for pulNumber excluding new task group id', async function () {