ADD rabbitmq

alpine-rabbitmq-cluster/Dockerfile

@@ -0,0 +1,8 @@
+FROM rabbitmq:3.6-management-alpine
+
+COPY join.sh /
+RUN chmod +x /join.sh
+
+RUN sed -i 's/exec "$@"/\
+    sh -c "while ! nc -z localhost 15672; do sleep 0.1; done; sleep 3; .\/join.sh" \&\
+    \nexec "$@"/' /usr/local/bin/docker-entrypoint.sh

alpine-rabbitmq-cluster/README.md

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+# RabbitMQ 集群
+
+## docker swarm (1.12 +)
+```
+version: "3.3"
+services:
+  rabbitmq:
+    image: jicki/rabbitmq-swarm
+    hostname: "{{.Service.Name}}.{{.Task.Slot}}.{{.Task.ID}}"
+    deploy:
+      replicas: 3
+      restart_policy:
+        condition: on-failure
+      update_config:
+        parallelism: 1
+        delay: 10s
+    environment:
+      - RABBITMQ_ERLANG_COOKIE=abc
+      - RABBITMQ_USE_LONGNAME=true
+      - RABBITMQ_MNESIA_DIR=/var/lib/rabbitmq/mnesia
+      - RABBITMQ_PLUGINS_EXPAND_DIR=/var/lib/rabbitmq/mnesia/plugins-expand
+      - SERVICE_NAME={{.Service.Name}}
+      - SLOT={{.Task.Slot}}
+      - MASTER_SLOT=1
+    ports:
+      - "5672:5672"   # amqp
+      - "15672:15672" # web ui
+```

alpine-rabbitmq-cluster/join.sh

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+#!/bin/bash
+#
+# Script to join rabbitmq cluster.
+#
+# This script is call in background once the mangement ui of this node is
+# running (see Dockerfile).
+#
+#
+
+# Wait a random amount of seconds (between 1 and 10 seconds) to get in
+# parallel started instances a littel bit out of sync.
+echo "Wait random duration..."
+sleep $[ ( $RANDOM % 10 )  + 10 ]s
+
+echo "Try to join rabbitmq cluster..."
+
+# busybox 'nslookup' required
+# Try to determine all hosts of this service (given by env var `SERVICE_NAME`).
+# Sometimes wrong hostnames are returned, hence the retry functionality.
+for i in `seq 5`
+do
+  if [[ "$i" > "5" ]]
+  then
+    echo "Retry count exceeded"
+    exit 1
+  fi
+  retry=false
+  nodes=`nslookup tasks.$SERVICE_NAME 2>/dev/null | grep -v $(hostname) | grep Address | awk '{print $4}' | cut -d. -f1-3`
+  for node in $nodes
+  do
+    if [[ "$node" != $SERVICE_NAME* ]]
+    then
+      retry=true
+      break
+    fi
+  done
+  if ! $retry; then break; fi
+done
+
+# If the service is configured with just one replica this rabbitmq instance is
+# running in standalone mode and no further cluster joining arithmetic is
+# required. If there are multiple nodes configured stop the app to start
+# setting up a cluster.
+echo
+if [[ ${#nodes} > 0 ]]
+then
+  echo "Found nodes of cluster:"
+  echo $nodes
+  rabbitmqctl stop_app
+  rabbitmqctl reset
+else
+  echo "Found standalone setup."
+  exit 0
+fi
+echo
+
+# Join cluster by trying one node after each other. If successfully joined, start the rabbitmq
+# app again
+while true
+do
+    for node in $nodes
+    do
+        # manually force a start by setting the env variable FORCE_START
+        if [[ -f /tmp/FORCE_START ]]
+        then
+            echo "Startup forced manually."
+            echo
+            rabbitmqctl start_app
+            exit 0
+        fi
+        # of peer is reachable try to join the cluster of that host
+        echo "Try to reach $node"
+        if nc -z "$node" 15672
+        then
+            rabbitmqctl join_cluster rabbit@$node
+            if [[ $? == "0" ]]
+            then
+                echo
+                echo "Start app after joining cluster"
+
+                rabbitmqctl start_app
+
+                echo
+                echo "Try to cleanup old nodes of same slot..."
+                for n in `rabbitmqctl cluster_status | awk '/disc/,/]}]}/' | grep -o "$SERVICE_NAME[^']*"`
+                do
+                    if [[ $n == "$SERVICE_NAME.$SLOT."* && $n != $HOSTNAME  ]]
+                    then
+                        echo
+                        echo "removing node $n from cluster"
+                        rabbitmqctl forget_cluster_node rabbit@$n
+                    fi
+                done
+                echo
+                echo "Successfully joined cluster"
+                exit 0
+            fi
+        elif [[ "$SLOT" == "$MASTER_SLOT" ]]
+        then
+            echo "Startup due to claimed master role on slot $MASTER_SLOT."
+            echo
+            rabbitmqctl start_app
+            exit 0
+        fi
+    done
+
+    sleep 10
+done
+
+echo "Failed to join cluster."
+exit 1