Quarkus RabbitMQ Lab

Description

The following is intended to showcase how to integrate Quarkus and RabbitMQ.

Environment

Building from Source

Source code artifacts are available in source and docker directories.

Lab Script

Start RabbitMQ
Start RabbitMQ Quarkus App
Send message to Default Exchange
Send Delayed message
Send Messages with Priority message

0. Start RabbitMQ

The easiest way to bootstrap RabbitMQ is using our custom docker image:

docker run -it -p 15672:15672 -p 5672:5672 viniciusmartinez/rabbitmq-quarkus:1.0

A similar output is expected:

2021-05-06 17:03:31.703 [info] <0.702.0> Statistics database started.
2021-05-06 17:03:31.704 [info] <0.701.0> Starting worker pool 'management_worker_pool' with 3 processes in it
2021-05-06 17:03:31.969 [info] <0.9.0> Server startup complete; 4 plugins started.
 * rabbitmq_management
 * rabbitmq_management_agent
 * rabbitmq_web_dispatch
 * rabbitmq_delayed_message_exchange
 completed with 4 plugins.

pleace notice that we added the rabbitmq_delayed_message_exchange plugin

You can access the admin console via http://localhost:15672 with guest for both Username and Password

1. Start RabbitMQ Quarkus App

Navigate to source/rabbitmq-quarkus-lab and bootstrap RabbitMQ Quarkus App: mvn quarkus:dev

A similar output is expected:

2021-05-06 14:16:48,627 INFO  [io.quarkus] (Quarkus Main Thread) rabbitmq-quarkus-lab 1.0.0-SNAPSHOT on JVM (powered by Quarkus 1.13.3.Final) started in 2.038s. Listening on: http://localhost:8080
2021-05-06 14:16:48,627 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2021-05-06 14:16:48,628 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [cdi, rabbitmq-client, resteasy, resteasy-jsonb, smallrye-context-propagation]

if the following exception comes up, please restart the application and the problem will be gone;

... 47 more
Caused by: com.rabbitmq.client.ShutdownSignalException: channel error; protocol method: #method<channel.close>(reply-code=404, reply-text=NOT_FOUND - no queue 'quarkus.queue.default' in vhost '/', class-id=60, method-id=20)

2. Send message to Default Exchange

We´ve created some Rest Endpoints to act as producers. Therefore, just POST a message on http://localhost:8080/rabbit. Example:

http POST :8080/rabbit message=message1
HTTP/1.1 200 OK
Content-Length: 23
Content-Type: application/json

{
   "message": "message1"
}

If you go back to RabbitMQ Quarkus App console, the following message is expected showcasing a working consumer:
```
Sending message to Default: {"message": "message1"}
Received message from
Exchange
Message: {"message": "message1"}
```
- notice that we don´t have any Exchange information since it´s the default one;

3. Send Delayed message

Just POST a message on http://localhost:8080/rabbit/delay. Example:

http POST :8080/rabbit/delay message=delayedmessage
HTTP/1.1 200 OK
Content-Length: 29
Content-Type: application/json

{
  "message": "delayedmessage"
}

If you go back to RabbitMQ Quarkus App console, the following message is expected showcasing a working consumer:
```
Sending message to Delayed: {"message": "delayedmessage"}
Received message from
Exchange quarkus.exchange.delay
Message: {"message": "delayedmessage"}
```
- notice that consumption takes much longer (10000 ms);

4. Send Messages with Priority

Just POST a message on http://localhost:8080/rabbit/message-priority. Example:

http POST :8080/rabbit/message-priority
HTTP/1.1 200 OK
Content-Length: 0

If you go back to RabbitMQ Quarkus App console, the following message is expected showcasing that we have three messages delivered to the broker

Received message from
Exchange quarkus.exchange.delay
Message: {"message": "delayedmessage2"}
Sending Priority Messages
Message Sent: MESSAGE 1
Message Sent: MESSAGE 2
Message Sent: MESSAGE 3

Now in order to consume these please, just execute a GET on http://localhost:8080/rabbit/message-priority
```
http :8080/rabbit/message-priority
HTTP/1.1 200 OK
Content-Length: 0
```
Switch back to RabbitMQ Quarkus App console and notice the messages consumption:
```
Higher Priority: MESSAGE 3
Medium Priority: MESSAGE 2
Lower Priority: MESSAGE 1
```
- notice that messages with higher priority are consumed firstly;

redhat-sa-brazil/quarkus-rabbitmq-lab