Update readme

Author: YuryHrytsuk

services/rabbit/README.md

@@ -1,6 +1,10 @@
+## Starting a cluster
+
+Make sure all nodes have joined the cluster before using it. Otherwise, number of replicas in quorum queues might be affected. Say, you have a cluster of 3 nodes. You connect to cluster before the 3rd node join it. Your quorum queue would end up with only 2 replicas and will be broken once, 1 node (of 2 nodes holding the replicas of the queue) goes down.
+
 ## Updating rabbitmq.conf / advanced.config (zero-downtime)
 
-rabbitmq.conf and advanced.config changes take effect after a node restart. This can be performed with zero-downtime when RabbitMQ is clustered (have multiple nodes). This can be achieved by stopping and starting rabbitmq nodes one by one
+We do not support this automated. But manually this can be achieved in case needed. `rabbitmq.conf` and `advanced.config` changes take effect after a node restart. This can be performed with zero-downtime when RabbitMQ is clustered (have multiple nodes). This can be achieved by stopping and starting rabbitmq nodes one by one
 * `docker exec -it <container-id> bash`
 * (inside container) `rabbitmqctl stop_app` and wait some time until node is stopped (can be seen in management ui)
 * (inside container) `rabbitmqctl start_app`

services/rabbit/docker-compose.yml.j2

@@ -26,7 +26,11 @@ services:
       timeout: 2s
       retries: 2
       interval: 10s
-
+    ports:
+      - target: 15672
+        published: 15672
+        protocol: tcp
+        mode: host
     networks:
       - rabbit
     configs:
@@ -95,6 +99,8 @@ services:
 
   subscriber:
     image: python:3.11
+    deploy:
+      replicas: 0
     command: sh -c "pip install pika && python /app/sub.py"
     environment:
       - RABBIT_HOSTS=rabbit_loadbalancer
@@ -107,6 +113,8 @@ services:
 
   publisher:
     image: python:3.11
+    deploy:
+      replicas: 0
     command: sh -c "pip install pika && python /app/pub.py"
     environment:
       - RABBIT_HOSTS=rabbit_loadbalancer

services/rabbit/test/pub.py

@@ -1,6 +1,5 @@
 import logging
 import os
-import random
 import time
 
 import pika
@@ -11,8 +10,15 @@
 logger = logging.getLogger(__name__)
 
 host = os.environ["RABBIT_HOSTS"].strip()
-credentials = pika.PlainCredentials(os.environ["RABBIT_USER"], os.environ["RABBIT_PASS"])
-parameters = pika.ConnectionParameters(host=host, port=5672, credentials=credentials, client_properties={"connection_name": "publisher"})
+credentials = pika.PlainCredentials(
+    os.environ["RABBIT_USER"], os.environ["RABBIT_PASS"]
+)
+parameters = pika.ConnectionParameters(
+    host=host,
+    port=5672,
+    credentials=credentials,
+    client_properties={"connection_name": "publisher"},
+)
 
 while True:
     connection = pika.BlockingConnection(parameters)
@@ -38,4 +44,4 @@
         logger.error(
             "Verbindung zum RabbitMQ Broker wurde geschlossen. Versuche erneut zu verbinden..."
         )
-        time.sleep(5)
+        time.sleep(1)

services/rabbit/test/sub.py

@@ -1,7 +1,7 @@
 import logging
 import os
-import random
 import time
+
 import pika
 
 logging.basicConfig(
@@ -10,8 +10,15 @@
 logger = logging.getLogger(__name__)
 
 host = os.environ["RABBIT_HOSTS"].strip()
-credentials = pika.PlainCredentials(os.environ["RABBIT_USER"], os.environ["RABBIT_PASS"])
-parameters = pika.ConnectionParameters(host=host, port=5672, credentials=credentials, client_properties={"connection_name": "subscriber"})
+credentials = pika.PlainCredentials(
+    os.environ["RABBIT_USER"], os.environ["RABBIT_PASS"]
+)
+parameters = pika.ConnectionParameters(
+    host=host,
+    port=5672,
+    credentials=credentials,
+    client_properties={"connection_name": "subscriber"},
+)
 
 while True:
     logger.info(f"Verbinde zu RabbitMQ Host: {host}")
@@ -36,4 +43,4 @@ def callback(ch, method, properties, body):
         logger.error(
             "Verbindung zum RabbitMQ Broker wurde geschlossen. Versuche erneut zu verbinden..."
         )
-        time.sleep(5)
+        time.sleep(1)