beter variable names

.dockerignore

@@ -6,9 +6,11 @@ Dockerfile
 .gitignore
 README.md
 *.example
+images
 .env
 env
 labels
 subscriptions.json
 
 
+

.env.example

@@ -4,7 +4,7 @@
 # Generate using: npx web-push generate-vapid-keys
 VAPID_PUBLIC_KEY=
 VAPID_PRIVATE_KEY=
-VAPID_SUBJECT=mailto:mailto:admin@virtonline.eu
+VAPID_SUBJECT=mailto:mailto:user@example.org
 
 # --- Server Configuration ---
 # Internal port for the Node.js app
@@ -32,9 +32,11 @@ ALLOWED_HEADERS=Content-Type,Authorization
 
 # --- Web Push Retry Configuration (Optional) ---
 # Number of retries on failure (e.g., DNS issues)
-MAX_NOTIFICATION_RETRIES=3    
+NOTIFICATION_MAX_RETRIES=3    
-# Initial delay in milliseconds
+# First retry delay in milliseconds (minimal delay for immediate retry)
-INITIAL_RETRY_DELAY_MS=1000
+NOTIFICATION_FIRST_RETRY_DELAY_MS=10
+# Base delay in milliseconds for subsequent retries (used for exponential backoff)
+NOTIFICATION_SUBSEQUENT_RETRY_DELAY_MS=1000
 
 # --- Network Configuration (Optional) ---
 # Timeout for DNS lookups (ms)

README.md

@@ -68,8 +68,9 @@ It's designed to be run as a Docker container and integrated with Traefik v3 for
         *   `ALLOWED_ORIGINS`: Comma-separated list of domains allowed by CORS. Include your PWA's domain if it needs to interact directly (e.g., for setup). Example: `https://my-pwa.com`.
         *   `ALLOWED_METHODS`: (Default: `POST,OPTIONS`) Standard methods needed.
         *   `ALLOWED_HEADERS`: (Default: `Content-Type,Authorization`) Standard headers needed.
-        *   `MAX_NOTIFICATION_RETRIES`: (Default: `3`) Number of retry attempts for failed push notifications. Must be a number.
+        *   `NOTIFICATION_MAX_RETRIES`: (Default: `3`) Number of retry attempts for failed push notifications. Must be a number.
-        *   `INITIAL_RETRY_DELAY_MS`: (Default: `1000`) Initial delay in milliseconds before first retry. Must be a number.
+        *   `NOTIFICATION_FIRST_RETRY_DELAY_MS`: (Default: `10`) Delay in milliseconds for the first retry attempt. Setting to 0-10ms provides near-immediate first retry for transient DNS issues. Must be a number.
+        *   `NOTIFICATION_SUBSEQUENT_RETRY_DELAY_MS`: (Default: `1000`) Base delay in milliseconds for subsequent retries. Each additional retry uses this value with exponential backoff and jitter. Must be a number.
         *   `DNS_TIMEOUT_MS`: (Default: `5000`) DNS resolution timeout in milliseconds. Must be a number.
         *   `HTTP_TIMEOUT_MS`: (Default: `10000`) HTTP request timeout in milliseconds. Must be a number.
         *   `LOG_LEVEL`: (Default: `info`) Controls verbosity of logs. Valid values are `error`, `warn`, `info`, or `debug`. Use `debug` to see detailed header information and other diagnostic messages.
@@ -245,4 +246,10 @@ If you receive a different response, refer to the Troubleshooting section below.
 *   **Verify `labels`:** Double-check that variables were correctly substituted manually and match your `.env` and Traefik setup.
 *   **Verify `subscriptions.json`:** Ensure it's valid JSON and the button serial number (key) matches exactly what Flic sends (check backend logs for "Received webhook: Button=..."). Check if the subscription details are correct. Case sensitivity matters for the JSON keys (button serials).
 *   **Check Flic Configuration:** Ensure the URL, Method, `click_type` parameter, and authentication details (Username/Password if enabled) are correct in the Flic action setup. Use `curl` or Postman to test the endpoint manually first.
-*   **PWA Service Worker:** Remember that the PWA needs a correctly registered Service Worker to receive and handle the incoming push messages. Ensure the PWA subscribes using the *same* `VAPID_PUBLIC_KEY` configured in the backend's `.env`.
+*   **PWA Service Worker:** Remember that the PWA needs a correctly registered Service Worker to receive and handle the incoming push messages. Ensure the PWA subscribes using the *same* `VAPID_PUBLIC_KEY` configured in the backend's `.env`.
+*   **Push Notification Retry Mechanism:** The service includes an optimized retry mechanism for handling temporary DNS resolution issues:
+    * First retry happens immediately or with minimal delay (controlled by `NOTIFICATION_FIRST_RETRY_DELAY_MS`, default 10ms)
+    * Subsequent retries use exponential backoff with jitter (starting from `NOTIFICATION_SUBSEQUENT_RETRY_DELAY_MS`, default 1000ms)
+    * Maximum number of retries is controlled by `NOTIFICATION_MAX_RETRIES` (default 3)
+    * This approach minimizes latency for transient DNS issues while preventing excessive requests for persistent problems
+    * Adjust these values in your `.env` file based on your network conditions and reliability requirements

server.js

@@ -24,8 +24,9 @@ const allowedOrigins = (process.env.ALLOWED_ORIGINS || "").split(',').map(origin
 const allowedMethods = (process.env.ALLOWED_METHODS || "POST,OPTIONS,GET").split(',').map(method => method.trim()).filter(method => method);
 const allowedHeaders = (process.env.ALLOWED_HEADERS || "Content-Type,Authorization").split(',').map(header => header.trim()).filter(header => header);
 // Retry configuration for DNS resolution issues
-const maxRetries = parseInt(process.env.MAX_NOTIFICATION_RETRIES || 3, 10);
+const maxRetries = parseInt(process.env.NOTIFICATION_MAX_RETRIES || 3, 10);
-const initialRetryDelay = parseInt(process.env.INITIAL_RETRY_DELAY_MS || 1000, 10); // 1 second
+const subsequentRetryDelay = parseInt(process.env.NOTIFICATION_SUBSEQUENT_RETRY_DELAY_MS || 1000, 10); // 1 second base delay for subsequent retries
+const firstRetryDelay = parseInt(process.env.NOTIFICATION_FIRST_RETRY_DELAY_MS || 10, 10); // 10 milliseconds - minimal delay for first retry
 // HTTP request timeout configuration
 const httpTimeout = parseInt(process.env.HTTP_TIMEOUT_MS || 10000, 10); // 10 seconds
 // Logging level configuration
@@ -98,7 +99,7 @@ dns.setServers(dns.getServers()); // Reset DNS servers (can help in some Docker
 // Example: dns.setServers(['8.8.8.8', '1.1.1.1']);
 
 // --- Utility function for retrying web push notifications with exponential backoff ---
-async function sendWebPushWithRetry(subscription, payload, retryCount = 0, delay = initialRetryDelay) {
+async function sendWebPushWithRetry(subscription, payload, retryCount = 0, delay = subsequentRetryDelay) {
   try {
     return await webpush.sendNotification(subscription, payload);
   } catch (error) {
@@ -108,13 +109,25 @@ async function sendWebPushWithRetry(subscription, payload, retryCount = 0, delay
                        error.code === 'ETIMEDOUT';
     
     if (isDnsError && retryCount < maxRetries) {
-      console.log(`DNS resolution failed (${error.code}). Retrying notification in ${delay}ms (attempt ${retryCount + 1}/${maxRetries})...`);
+      // For first retry (retryCount = 0), use minimal delay or no delay
+      const actualDelay = retryCount === 0 ? firstRetryDelay : delay;
       
-      // Wait for the delay
+      if (retryCount === 0) {
-      await new Promise(resolve => setTimeout(resolve, delay));
+        logger.info(`DNS resolution failed (${error.code}). Retrying notification immediately or with minimal delay of ${firstRetryDelay}ms (attempt ${retryCount + 1}/${maxRetries})...`);
+      } else {
+        logger.info(`DNS resolution failed (${error.code}). Retrying notification in ${actualDelay}ms (attempt ${retryCount + 1}/${maxRetries})...`);
+      }
       
-      // Exponential backoff with jitter
+      // Wait for the delay (minimal or none for first retry)
-      const nextDelay = delay * (1.5 + Math.random() * 0.5);
+      if (actualDelay > 0) {
+        await new Promise(resolve => setTimeout(resolve, actualDelay));
+      }
+      
+      // Calculate next delay with exponential backoff + jitter
+      // First retry uses subsequentRetryDelay, subsequent retries use exponential increase
+      const nextDelay = retryCount === 0 ? 
+                       subsequentRetryDelay : 
+                       delay * (1.5 + Math.random() * 0.5);
       
       // Retry recursively with increased count and delay
       return sendWebPushWithRetry(subscription, payload, retryCount + 1, nextDelay);
@@ -360,7 +373,7 @@ server.listen(port, () => {
   }
   logger.info(`Subscription Endpoint Auth: ${basicAuthUsername && basicAuthPassword ? 'Enabled (Basic)' : 'Disabled'}`);
   logger.info(`Subscriptions File: ${subscriptionsFilePath}`);
-  logger.info(`Push Notification Retry Config: ${maxRetries} retries, ${initialRetryDelay}ms initial delay`);
+  logger.info(`Push Notification Retry Config: ${maxRetries} retries, first retry: ${firstRetryDelay}ms, subsequent retries: ${subsequentRetryDelay}ms base delay`);
   logger.info(`DNS Config: IPv4 first, timeout ${dnsTimeout}ms`);
   logger.info(`HTTP Timeout: ${httpTimeout}ms`);
   logger.info(`Log Level: ${LOG_LEVEL.toUpperCase()}`);

virt-flic-webhook-webpush.service.example

@@ -7,20 +7,18 @@ DefaultDependencies=no
 [Service]
 Type=simple
 Environment="HOME=/root"
-Environment="APP_PATH=/virt/flic-webhook-webpush"
-
 ExecStartPre=-/usr/bin/env sh -c '/usr/bin/env docker kill virt-flic-webhook-webpush 2>/dev/null || true'
 ExecStartPre=-/usr/bin/env sh -c '/usr/bin/env docker rm virt-flic-webhook-webpush 2>/dev/null || true'
-ExecStartPre=/usr/bin/env sh -c 'touch ${APP_PATH}/subscriptions.json'
+ExecStartPre=/usr/bin/env sh -c 'touch /virt/flic-webhook-webpush/subscriptions.json'
 
 ExecStart=/usr/bin/env docker run \
                         --rm \
                         --name=virt-flic-webhook-webpush \
 			--log-driver=none \
                         --network=traefik \
-                        --env-file=${APP_PATH}/env \
+                        --env-file=/virt/flic-webhook-webpush/env \
-			--label-file=${APP_PATH}/labels \
+			--label-file=/virt/flic-webhook-webpush/labels \
-                        --mount type=bind,src=${APP_PATH}/subscriptions.json,dst=/app/subscriptions.json \
+                        --mount type=bind,src=/virt/flic-webhook-webpush/subscriptions.json,dst=/app/subscriptions.json \
                                 flic-webhook-webpush
 
 ExecStop=-/usr/bin/env sh -c '/usr/bin/env docker kill virt-flic-webhook-webpush 2>/dev/null || true'