Reorg script

bin/apply-config.mjs

@@ -0,0 +1,106 @@
+/**
+ * This script calls the applyConfig Lambda function, waits for the ECS task to complete,
+ * and fetches the logs from CloudWatch Logs.
+ *
+ * Usage: npm run apply-config <lambdaArn>
+ */
+
+import { LambdaClient, InvokeCommand } from "@aws-sdk/client-lambda";
+import {
+  ECSClient,
+  DescribeTasksCommand,
+  DescribeTaskDefinitionCommand,
+} from "@aws-sdk/client-ecs";
+import {
+  CloudWatchLogsClient,
+  GetLogEventsCommand,
+} from "@aws-sdk/client-cloudwatch-logs";
+
+let exitCode = null;
+
+main()
+  .then((logs) => {
+    console.log("Task output:");
+    logs.forEach((l) => console.log(l));
+  })
+  .catch((error) => {
+    console.error(`Error: ${error}`);
+    exitCode = 1;
+  })
+  .finally(() => process.exit(exitCode));
+
+async function main() {
+  const [, , lambdaArn] = process.argv;
+  const { taskArn, clusterArn } = await invokeLambda(lambdaArn);
+  const ecs = new ECSClient({});
+  const task = await pollEcsTask(ecs, taskArn, clusterArn);
+  exitCode = task.containers[0]?.exitCode ?? null;
+  if (exitCode === null)
+    throw new Error("Could not retrieve exit code from the ECS task.");
+
+  const { logGroup, logStreamPrefix, region, containerName } =
+    await getLogConfig(ecs, task.taskDefinitionArn);
+  const taskId = taskArn.split("/").pop();
+  const logStreamName = `${logStreamPrefix}/${containerName}/${taskId}`;
+  return fetchCloudWatchLogs(logGroup, logStreamName, region);
+}
+
+async function invokeLambda(lambdaArn) {
+  const lambda = new LambdaClient({});
+  const response = await lambda.send(
+    new InvokeCommand({
+      FunctionName: lambdaArn,
+      InvocationType: "RequestResponse",
+      Payload: new TextEncoder().encode(JSON.stringify({})),
+    })
+  );
+  return JSON.parse(new TextDecoder().decode(response.Payload));
+}
+
+async function pollEcsTask(ecs, taskArn, clusterArn) {
+  while (true) {
+    const { tasks } = await ecs.send(
+      new DescribeTasksCommand({ cluster: clusterArn, tasks: [taskArn] })
+    );
+    const task = tasks?.[0];
+    if (!task) throw new Error(`No tasks found with taskArn: ${taskArn}`);
+    console.log(`Task status: ${task.lastStatus}`);
+    if (task.lastStatus === "STOPPED") return task;
+    await new Promise((resolve) => setTimeout(resolve, 5000));
+  }
+}
+
+async function getLogConfig(ecs, taskDefinitionArn) {
+  const { taskDefinition } = await ecs.send(
+    new DescribeTaskDefinitionCommand({ taskDefinition: taskDefinitionArn })
+  );
+  const containerDef = taskDefinition.containerDefinitions[0];
+  if (containerDef.logConfiguration?.logDriver !== "awslogs")
+    throw new Error("Log driver is not 'awslogs'.");
+  return {
+    logGroup: containerDef.logConfiguration.options["awslogs-group"],
+    logStreamPrefix:
+      containerDef.logConfiguration.options["awslogs-stream-prefix"],
+    region: containerDef.logConfiguration.options["awslogs-region"],
+    containerName: containerDef.name,
+  };
+}
+
+async function fetchCloudWatchLogs(logGroup, logStreamName, region) {
+  const logsClient = new CloudWatchLogsClient({ region });
+  let nextToken,
+    events = [];
+  do {
+    const { events: newEvents, nextForwardToken } = await logsClient.send(
+      new GetLogEventsCommand({
+        logGroupName: logGroup,
+        logStreamName,
+        startFromHead: true,
+        nextToken,
+      })
+    );
+    events.push(...newEvents);
+    nextToken = nextForwardToken !== nextToken ? nextForwardToken : null;
+  } while (nextToken);
+  return events.map((event) => event.message);
+}

package.json

@@ -8,7 +8,7 @@
     "build": "tsc",
     "watch": "tsc -w",
     "cdk": "cdk",
-    "apply-config": "node ./config/apply-config.mjs"
+    "apply-config": "node ./bin/apply-config.mjs"
   },
   "devDependencies": {
     "@aws-sdk/client-cloudwatch-logs": "^3.680.0",