Handle python's 120 exit code

changelog.md

@@ -1,3 +1,7 @@
+### 4.20.3
+
+- Treat a rare python exit code of 120 as a special case of exit code 3 (#340).
+
 ### 4.20.2
 
 - Using InChina instead of NotInChina Cloudformation condition: https://github.com/mapbox/ecs-watchbot/pull/329

lib/worker.js

@@ -99,6 +99,9 @@ class Worker {
       if (results.code === 0) return await this.success(results);
       if (results.code === 3) return await this.ignore(results);
       if (results.code === 4) return await this.noop(results);
+      // Rarely, python may set an exit code of 120 during its cleanup phase.
+      // We should not retry in this case.
+      if (results.code === 120) return await this.ignore(results);
       return await this.fail(results);
     } catch (err) {
       clearInterval(heartbeatTimeout);

test/worker.test.js

@@ -336,6 +336,34 @@ test('[worker] waitFor, exit 4', async (assert) => {
   assert.end();
 });
 
+test('[worker] waitFor, exit 120', async (assert) => {
+  const logger = stubber(Logger).setup();
+  logger.log.restore();
+  logger.stream.restore();
+  const message = sinon.createStubInstance(Message);
+  message.env = { Message: 'forty bananas', SentTimestamp: '2019-02-09T21:57:55.000Z' };
+  const options = { command: 'exit 120', volumes: ['/tmp'] };
+  const worker = new Worker(message, options);
+
+  sinon.spy(child_process, 'spawn');
+
+  try {
+    await worker.waitFor();
+  } catch (err) {
+    assert.ifError(err, 'failed');
+  }
+
+  const results = logger.workerFailure.args[0][0];
+  assert.equal(results.code, 120, 'logged worker failure exit code');
+  assert.ok(results.duration, 'logged worker failure duration');
+  assert.ok(results.response_duration, 'logged worker response duration');
+  assert.equal(message.complete.callCount, 1, 'calls message.complete()');
+
+  child_process.spawn.restore();
+  logger.teardown();
+  assert.end();
+});
+
 test('[worker] waitFor, child_process.spawn failure', async (assert) => {
   const logger = stubber(Logger).setup();
   logger.log.restore();