fix: Correctly configure Log4JS when running in ECS

docker-compose.yaml

@@ -0,0 +1,53 @@
+# A Docker Compose file for running the production build locally.
+# Usage:
+#   docker compose up -d --build --force-recreate
+services:
+  tag-page-rendering:
+    build:
+      dockerfile: ./Production.dockerfile
+    environment:
+      NODE_ENV: production
+      GU_STAGE: PROD
+      GU_APP: tag-page-rendering
+      GU_STACK: frontend
+
+      # We configure Log4JS based on this environment variable. See `server/lib/logging.ts`.
+      AWS_EXECUTION_ENV: AWS_ECS_LOCAL
+
+      # Explicitly tell AWS SDK where to find credentials
+      AWS_SHARED_CREDENTIALS_FILE: /.aws/credentials
+    ports:
+      - '9000:9000'
+
+    # Share the host's AWS credentials with the container
+    volumes:
+      - ${HOME}/.aws/credentials:/.aws/credentials:ro
+
+    # In Production.dockerfile, we're deliberately using a minimal image that does not have `curl` installed.
+    # Therefore, we're using Node to make a request to the healthcheck endpoint instead of using `curl`.
+    healthcheck:
+      test:
+        [
+          'CMD',
+          'node',
+          '-e',
+          "fetch('http://localhost:9000/_healthcheck').then(_ => process.exit(0)).catch(_ => process.exit(1))",
+        ]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  # This service is used to make a sample request to tag-page-rendering only after it has started and is healthy.
+  # It exits immediately after making the request, so it is not a long-running service.
+  # View the logs via:
+  #   docker logs "$(docker ps -aq --filter "name=sample-request" --latest)"
+  # The log output is the DCR response, so we can also pipe it through `jq` to pretty-print it, e.g.:
+  #   docker logs "$(docker ps -aq --filter "name=sample-request" --latest)" | jq .
+  sample-request:
+    image: curlimages/curl:8.21.0
+    depends_on:
+      tag-page-rendering:
+        condition: service_healthy
+    command: |
+      curl "https://www.theguardian.com/tone/minutebyminute.json?dcr=true" --silent > data.json && \
+        curl -X POST http://localhost:9000/TagPage -d @data.json -H "Content-Type: application/json"

dotcom-rendering/src/server/lib/logging.ts

@@ -4,14 +4,6 @@ import type { Configuration, Layout, LoggingEvent } from 'log4js';
 import { addLayout, configure, getLogger, shutdown } from 'log4js';
 import { type DCRLoggingStore, loggingStore } from './logging-store';
 
-const logName = `dotcom-rendering.log`;
-
-const logLocation =
-	process.env.NODE_ENV === 'production' &&
-	!process.env.DISABLE_LOGGING_AND_METRICS
-		? `/var/log/dotcom-rendering/${logName}`
-		: `${path.resolve('logs')}/${logName}`;
-
 type LogFields = Partial<DCRLoggingStore> &
 	Record<string | number | symbol, unknown>;
 
@@ -84,39 +76,69 @@ const disableLog4js: Configuration = {
 	},
 };
 
-const enableLog4js: Configuration = {
-	appenders: {
-		console: {
-			type: 'console',
-			layout: consoleLayout,
+function configureLog4jsEC2() {
+	const logName = `dotcom-rendering.log`;
+
+	const logLocation =
+		process.env.NODE_ENV === 'production' &&
+		!process.env.DISABLE_LOGGING_AND_METRICS
+			? `/var/log/dotcom-rendering/${logName}`
+			: `${path.resolve('logs')}/${logName}`;
+
+	configure({
+		appenders: {
+			console: {
+				type: 'console',
+				layout: consoleLayout,
+			},
+			fileAppender: {
+				type: 'file',
+				filename: logLocation,
+				maxLogSize: '5M',
+				backups: 5,
+				compress: true,
+				layout: { type: 'json', separator: ',' },
+				// Owner Read & Write, Group Read
+				mode: 0o640,
+			},
+			out: {
+				type: 'stdout',
+				layout: { type: 'json', separator: ',' },
+			},
 		},
-		fileAppender: {
-			type: 'file',
-			filename: logLocation,
-			maxLogSize: '5M',
-			backups: 5,
-			compress: true,
-			layout: { type: 'json', separator: ',' },
-			// Owner Read & Write, Group Read
-			mode: 0o640,
+		categories: {
+			default: { appenders: ['out'], level: 'off' },
+			production: { appenders: ['out', 'fileAppender'], level: 'info' },
+			code: { appenders: ['out', 'fileAppender'], level: 'debug' },
+			development: { appenders: ['console'], level: 'debug' },
 		},
-		out: {
-			type: 'stdout',
-			layout: { type: 'json', separator: ',' },
+		// log4js cluster mode handling does not work as it prevents
+		// logs from processes other than the main process from
+		// writing to the log.
+		disableClustering: true,
+	});
+}
+
+function configureLog4jsECS() {
+	configure({
+		appenders: {
+			out: {
+				type: 'stdout',
+				layout: { type: 'json', separator: ',' },
+			},
 		},
-	},
-	categories: {
-		default: { appenders: ['out'], level: 'off' },
-		production: { appenders: ['out', 'fileAppender'], level: 'info' },
-		code: { appenders: ['out', 'fileAppender'], level: 'debug' },
-		development: { appenders: ['console'], level: 'debug' },
-		container: { appenders: ['out'], level: 'info' },
-	},
-	// log4js cluster mode handling does not work as it prevents
-	// logs from processes other than the main process from
-	// writing to the log.
-	disableClustering: true,
-};
+		categories: {
+			default: { appenders: ['out'], level: 'info' },
+			production: { appenders: ['out'], level: 'info' },
+			code: { appenders: ['out'], level: 'debug' },
+			development: { appenders: ['out'], level: 'debug' },
+		},
+		// log4js cluster mode handling does not work as it prevents
+		// logs from processes other than the main process from
+		// writing to the log.
+		disableClustering: true,
+	});
+}
 
 // We do this to ensure no memory leaks during development as hot reloading
 // doesn't clear up old listeners.
@@ -132,20 +154,21 @@ if (process.env.NODE_ENV === 'development') {
 if (process.env.DISABLE_LOGGING_AND_METRICS === 'true') {
 	configure(disableLog4js);
 } else {
-	configure(enableLog4js);
+	// See https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-environment-variables.html
+	const runningInECS =
+		process.env.AWS_EXECUTION_ENV?.startsWith('AWS_ECS_') === true;
+
+	if (runningInECS) {
+		configureLog4jsECS();
+	} else {
+		configureLog4jsEC2();
+	}
 }
 
 const getLoggerCategory = (): string => {
 	if (process.env.DISABLE_LOGGING_AND_METRICS === 'true') {
 		return 'off';
 	}
-
-	// Are we running in a container?
-	// See https://docs.aws.amazon.com/AmazonECS/latest/developerguide/ecs-environment-variables.html
-	if (process.env.AWS_EXECUTION_ENV?.startsWith('AWS_ECS_') === true) {
-		return 'container';
-	}
-
 	if (process.env.NODE_ENV === 'development') {
 		return 'development';
 	}