update 0.1.2

README.md

@@ -1,11 +1,11 @@
 # Alpine :: Traefik Labels
-![size](https://img.shields.io/docker/image-size/11notes/traefik-labels/0.1.0?color=0eb305) ![version](https://img.shields.io/docker/v/11notes/traefik-labels?color=eb7a09) ![pulls](https://img.shields.io/docker/pulls/11notes/traefik-labels?color=2b75d6) ![activity](https://img.shields.io/github/commit-activity/m/11notes/docker-traefik-labels?color=c91cb8) ![commit-last](https://img.shields.io/github/last-commit/11notes/docker-traefik-labels?color=c91cb8)
+![size](https://img.shields.io/docker/image-size/11notes/traefik-labels/0.1.2?color=0eb305) ![version](https://img.shields.io/docker/v/11notes/traefik-labels?color=eb7a09) ![pulls](https://img.shields.io/docker/pulls/11notes/traefik-labels?color=2b75d6) ![activity](https://img.shields.io/github/commit-activity/m/11notes/docker-traefik-labels?color=c91cb8) ![commit-last](https://img.shields.io/github/last-commit/11notes/docker-traefik-labels?color=c91cb8)
 
 Run Traefik Labels based on Alpine Linux. Small, lightweight, secure and fast 🏔️
 
 What can I do with this? Simply put: It will export any traefik labels on a container on the same host as this image runs to a Redis instance. This makes it possible for a centralized Traefik load balancer to update endpoints dynamically by utilizing the docker labels, just like you would on a local installation of Traefik with labels. It is meant as an alternative and simple way to proxy requests from a Traefik load balanacer to multiple docker nodes running in different networks and locations.
 
-In order to use this image, you need to setup Traefik with a Redis provider and then point this image via REDIS_URL to the same Redis instance. Each entry will have an expire timer set in Redis, so that if a container is removed by a server crashing, Redis will automatically remove stale entries as well. Entries are refreshed every 60 seconds or an all docker container events (create, run, kill, stop, restart, ...).
+In order to use this image, you need to setup Traefik with a Redis provider and then point this image via REDIS_URL to the same Redis instance. Each entry will have an expire timer set in Redis, so that if a container is removed by a server crashing, Redis will automatically remove stale entries as well. Entries are refreshed every 60 seconds or on all docker container events (create, run, kill, stop, restart, ...).
 
 ## Run
 This will export all labels from all containers to the Redis instance specified in LABELS_REDIS_URL from the same host this container is running on.
@@ -40,33 +40,8 @@ docker run --name demo \
 | Parameter | Value | Default |
 | --- | --- | --- |
 | `LABELS_REDIS_URL` | the redis URL to connect, use rediss:// for SSL | redis:://localhost:6379/0 |
-| `LABELS_INTERVAL` | in what interval container information is pulled | 60 |
-| `LABELS_TIMEOUT` | how many seconds after an interval the keys should stay till they expire | 15 |
-
-## Example
-```mermaid
-flowchart TB
-    
-    subgraph Edge
-        A[WAN]:::WAN -->|:8443| B(keepalived VIP):::KEEPALIVED
-    end
-    
-    subgraph Domain_B
-    B -->|:8443| C(Traefik):::TRAEFIK
-    C -->|:6379| E(Redis):::REDIS
-    end
-    subgraph Domain_A
-    B -->|:8443| D(Traefik):::TRAEFIK
-    D -->|:6379| F(Redis):::REDIS
-    end
-
-    classDef WAN fill:#000000,stroke:none,color#FFF
-    classDef KEEPALIVED fill:#CC9933,stroke:none,color#000
-    classDef TRAEFIK fill:#3399CC,stroke:none,color:#FFF
-    classDef REDIS fill:#AA0000,stroke:none,color:#FFF
-
-```
-
+| `LABELS_INTERVAL` | in what interval container information is pulled | 300 |
+| `LABELS_TIMEOUT` | how many seconds after an interval the keys should stay till they expire | 30 |
 
 ## Parent image
 * [11notes/node:stable](https://github.com/11notes/docker-node)

amd64.dockerfile

@@ -1,6 +1,6 @@
 # :: Header
   FROM 11notes/node:stable
-  ENV APP_VERSION=0.1.0
+  ENV APP_VERSION=0.1.1
   ENV APP_ROOT=/labels
 
 # :: Run

rootfs/labels/app.js

@@ -1,14 +1,24 @@
 const Docker = require('dockerode');
 const redis = require('redis');
+const ERROR = 1;
 
 class Labels{
   #docker;
   #redis;
+  #poll = false;
 
   constructor(){
     this.#docker = new Docker({socketPath: '/run/docker.sock'});
   }
 
+  #log(message, error){
+    console.log(JSON.stringify({
+      time:new Date().toISOString(),
+      type:(error === ERROR) ? 'ERROR' : 'INFO',
+      message:message,
+    }));
+  }
+
   async watch(){
     this.#redis = await redis.createClient({
       url:process.env.LABELS_REDIS_URL,
@@ -20,54 +30,76 @@ class Labels{
 
     this.#redis.connect();
     this.#redis.on('ready', ()=>{
+      this.#log('connected to Redis');
+      (async() => {
+        await this.dockerPoll();
+      })();
       this.dockerEvents();
     });
 
     this.#redis.on('error', error =>{
-      console.error(error);
+      this.#log(error, ERROR);
     });
 
-    setInterval(() => {
-      this.dockerPoll();
+    setInterval(async() => {
+      await this.dockerPoll();
     }, parseInt(process.env.LABELS_INTERVAL)*1000);
   }
 
   dockerEvents(){
     this.#docker.getEvents({}, (error, data) => {
-      data.on('data', (chunk) => {
+      data.on('data', async(chunk) => {
         const event = JSON.parse(chunk.toString('utf8'));
         if(/Container/i.test(event?.Type) && /start|stop|restart|kill|die|destroy/i.test(event?.status)){
-          this.dockerInspect(event.id, event.status);
+          this.#log(`new docker event for container ${event.id}`);
+          await this.dockerInspect(event.id, event.status);
         }
       });
     });
   }
 
-  dockerPoll(){
-    this.#docker.listContainers((error, containers) => {
-      containers.forEach(container => {
-        this.dockerInspect(container.Id, 'start');
-      });
-    });
+  async dockerPoll(){
+    if(!this.#poll){
+      try{
+        this.#poll = true;
+        this.#log(`poll start (interval:${process.env.LABELS_INTERVAL})}`);
+        this.#docker.listContainers((error, containers) => {
+          containers.forEach(async(container) => {
+            await this.dockerInspect(container.Id, 'start');
+          });
+        });
+      }catch(e){
+        this.#log(e, ERROR);
+      }finally{
+        this.#log('poll end');
+        this.#poll = false;
+      }
+    }
   }
 
   dockerInspect(id, status = null){
-    const container = this.#docker.getContainer(id);
-    container.inspect(async(error, data) => {
-      for(const label in data?.Config?.Labels){
-        if(/traefik\//i.test(label)){
-          switch(true){
-            case /start|restart/i.test(status):
-              await this.#redis.set(label, data?.Config?.Labels[label], {EX:parseInt(process.env.LABELS_INTERVAL) + parseInt(process.env.LABELS_TIMEOUT)});
-            break;
+    return(new Promise((resolve, reject) => {
+      const container = this.#docker.getContainer(id);
+      container.inspect(async(error, data) => {
+        if(error){
+          reject(error);
+        }
+        for(const label in data?.Config?.Labels){
+          if(/traefik\//i.test(label)){
+            switch(true){
+              case /start|restart/i.test(status):
+                await this.#redis.set(label, data?.Config?.Labels[label], {EX:parseInt(process.env.LABELS_INTERVAL) + parseInt(process.env.LABELS_TIMEOUT)});
+              break;
 
-            case /stop|kill|die|destroy/i.test(status):
-              await this.#redis.del(label);
-            break;
+              case /stop|kill|die|destroy/i.test(status):
+                await this.#redis.del(label);
+              break;
+            }
           }
         }
-      }
-    });
+        resolve(true);
+      });
+    }));
   }
 }
 

rootfs/labels/main.js

@@ -4,8 +4,8 @@ const { fork } = require('node:child_process');
 const child = fork(`${__dirname}/app.js`, [], {
   env:{
     LABELS_REDIS_URL:process.env?.LABELS_REDIS_URL || 'redis:://localhost:6379/0',
-    LABELS_INTERVAL:parseInt(process.env?.LABELS_INTERVAL || 60),
-    LABELS_TIMEOUT:parseInt(process.env?.LABELS_TIMEOUT|| 15),
+    LABELS_INTERVAL:parseInt(process.env?.LABELS_INTERVAL || 300),
+    LABELS_TIMEOUT:parseInt(process.env?.LABELS_TIMEOUT|| 30),
   }
 });
 child.on('error', (error) =>{