Program to make a proxy (ie HAProxy) capable of monitoring RabbitMQ nodes properly.

Inspired by https://github.com/larrabee/pxc-checker

Basic Haproxy config:

listen rabbit
  bind 127.0.0.1:5672
  balance leastconn
  option httpchk GET /api/aliveness-test/%2F HTTP/1.1\r\nAuthorization:\ Basic\ [BASIC-AUTH]\r\nHost:\ Rabbit\r\nHealthcheck:\ haproxy
  mode tcp
  default-server inter 500 rise 5 fall 5
    server node1 1.2.3.4:5672 check port 15672
    server node2 1.2.3.5:5672 check port 15672
    server node3 1.2.3.6:5672 check port 15672 backup

1. Enable RabbitMQ management plugin at 15672 (default) or custom port.
2. Add user with publish access to /
3. Generate Basic auth header https://www.blitter.se/utils/basic-authentication-header-generator/
4. Get program binary. You can choose one of the following methods:
   • Build it from source code with:

     go get
     go build -o rabbitmq-checker ./...
     

   • Download latest compiled binary from Releases page.
5. Copy binary to /usr/bin/rabbitmq-checker
6. Copy systemd unit from systemd/rabbitmq-checker@service to /etc/systemd/system/rabbitmq-checker@service
7. Copy example config from config/example.conf to /etc/rabbitmq/checker.conf and modify it.
8. Enable and start unit with command: `systemctl enable --now rabbitmq-checker@service
9. Check node status with command: curl http://127.0.0.1:9672

You can override any of the following values in configuration file:

• WEB_LISTEN : Web server listening interface and port in format {IPADDR}:{PORT} or :PORT for all interfaces. Default: :9672, support IPv6 bind
• CHECK_FORCE_ENABLED: Ignoring the status of the checks and always marking the node as available. Default: false
• CHECK_INTERVAL: RabbitMQ checks interval in milliseconds. Default: 1000
• CHECK_FAIL_TIMEOUT: Mark the node inaccessible if for the specified time (in milliseconds) there were no successful checks. Default: 3000
• RABBITMQ_HOST : Rabbit host address. Default 127.0.0.1
• RABBITMQ_WEB_PORT : Rabbit management port. Default 15672
• RABBITMQ_BASIC_AUTH : RabbitMQ basic auth for management interface, no defaults
• DEBUG : Log every request to RabbitMQ. Default false