Merge pull request #11 from endlessm/T35672-support-redis-tls

Allow connecting to Redis with TLS
endlessm · Sep 30, 2024 · 92bba54 · 92bba54
2 parents 15ddd15 + 8373c45
commit 92bba54
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Showing 5 changed files with 62 additions and 12 deletions.
diff --git a/api/activation.js b/api/activation.js
@@ -61,7 +61,7 @@ const activation = (router, logger) => {
       res.status(200)
          .json({ success: true });
     }).catch((err) => {
-      logger.error(err);
+      logger.error('Failed to save activation: ' + err);
 
       res.status(500)
          .json({ error: err.toString(),

diff --git a/api/ping.js b/api/ping.js
@@ -60,7 +60,7 @@ const ping = (router, logger) => {
       res.status(200)
          .json({ success: true });
     }).catch((err) => {
-      logger.error(err);
+      logger.error('Failed to save ping: ' + err);
 
       res.status(500)
          .json({ error: err.toString(),

diff --git a/app.js b/app.js
@@ -27,18 +27,20 @@ app.use(api.router);
 
 // Error handler
 app.use((err, req, res, next) => {
-  if (err) {
-    logger.error(err);
+  logger.error(`while handling ${req.method} ${req.url}: ${err}`);
 
-    let errorMessage = "Server error";
-    if (process.env.NODE_ENV == 'test') {
-      errorMessage = err.toString() + '\n' + err.stack;
-    }
+  if (res.headersSent) {
+    return next(err);
+  }
 
-    res.status(500)
-       .json({ error: errorMessage,
-               success: false });
+  let errorMessage = "Server error";
+  if (process.env.NODE_ENV == 'test') {
+    errorMessage = err.stack;
   }
+
+  res.status(500)
+     .json({ error: errorMessage,
+             success: false });
 });
 
 logger.info('Server starting on ' +

diff --git a/config/index.js b/config/index.js
@@ -11,10 +11,11 @@ const server_bind_address = process.env.BIND_ADDRESS || '127.0.0.1';
 const redis_host = process.env.REDIS_HOST || '127.0.0.1';
 const redis_port = parseInt(process.env.REDIS_PORT, 10) || 6379;
 const redis_password = process.env.REDIS_PASSWORD || '';
+const redis_tls = ["true", "1"].includes((process.env.REDIS_TLS || '').toLowerCase());
 
 // Crash handler
 process.on('uncaughtException', (err) => {
-  logger.error(err.stack);
+  logger.error(`Uncaught exception: ${err.stack}`);
   process.exit(1);
 });
 
@@ -26,4 +27,5 @@ exports = module.exports = {
   redis_host,
   redis_port,
   redis_password,
+  redis_tls,
 };
diff --git a/util/redis.js b/util/redis.js
@@ -12,10 +12,56 @@ exports = module.exports = {
   redisPort: config.redis_port,
   redisPassword: config.redis_password,
   getRedis: (callback) => {
+    /* ioredis uses tls.connect() if the tls option is set, and passes it as
+     * additional options to tls.connect().
+     */
+    let tls = config.redis_tls ? {} : undefined;
+
     const redis = new Redis({
       host: config.redis_host,
       port: config.redis_port,
       password: config.redis_password,
+      tls,
+      reconnectOnError(err) {
+        /* Reconnect when ElastiCache has promoted some other node to primary & 
+         * demoted the node we are connected to a replica.
+         * https://github.com/redis/ioredis/blob/main/README.md#reconnect-on-error
+         */
+        var targetError = 'READONLY';
+        if (err.message.slice(0, targetError.length) === targetError) {
+          config.logger.info(`Reconnecting due to error: ${err.message}`);
+          /* Possible return values:
+           * - 0: don't reconnect
+           * - 1 or true: reconnect
+           * - 2: reconnect, and then resend the failed command
+           * Returning 2 is appealing but if, after reconnecting, the resent
+           * command fails with READONLY, then we will loop; and unlike in the
+           * case of a connection error, there is no backoff between
+           * reconnection attempts.
+           *
+           * The client (eos-phone-home) will retry failed requests on its next
+           * run (typically after 3 hours or after a network change) so it is
+           * not imperative to retry on the server.
+           */
+          return 2;
+        }
+      },
+    });
+
+    redis.on('connect', () => {
+      config.logger.info('Connected to Redis server');
+    });
+    redis.on('ready', () => {
+      config.logger.info('Redis connection ready');
+    });
+    redis.on('reconnecting', (delay) => {
+      config.logger.info(`Reconnecting to ${config.redis_host}:${config.redis_port} in ${delay} ms`);
+    });
+    redis.on('close', () => {
+      config.logger.info('Disconnected from Redis server');
+    });
+    redis.on('error', (err) => {
+      config.logger.error('Error connecting to Redis server: ' + err);
     });
 
     callback(redis);