Prologue

Sometimes you may want to send a message to someone, but don’t want to do it yourself. How to achieve this? Find someone else to send it! Then, if there are too many messages and you don’t want to receive them at once? Stash them somewhere else, and take them at your own pace!

So this is the basic idea of AMQP (Advanced Message Queue Protocol), a message-oriented middleware. It allows you to publish messages to a queue and consume them in various methods. One of the most famous implementations is RabbitMQ. In this article, I will talk about the installation of it and the basic use of its client.

I’ll only talk about the Linux installation, specifically Ubuntu 20.04.

You can refer to the official Tutorial for basic concepts.

1. Installation

1.1 Erlang

As we know, RabbitMQ is written in Erlang, so we need to install it first as the dependency. But be warned, not all Erlang versions are supported, so choose carefully. Check Erlang Version Requirements for more information. In my case, the latest version of RabbitMQ is 3.13.3, having support for Erlang 26. You can visit Erlang official page for source code download.

For example, we use Erlang 26.2.5, and extract the tar.gz with tar -xvf. You may need ncurses-dev installed.

1	sudo apt install ncurses-dev

Then, just create installation directory and build Erlang.

mkdir /opt/erlang
./configure --prefix=/opt/erlang
make -j
make install

Finally, add Erlang to the system PATH.

1 2	export ERLANG_HOME=/opt/erlang export PATH="$PATH:$ERLANG_HOME/bin"

You should have Erlang installed now. You can use erl to start Erlang console.

1.2 RabbitMQ

First, let’s get the latest RabbitMQ release from GitHub, for me it’s 3.13.3. Then use tar -xvf to extract it and copy it to /opt/rabbitmq_server-3.13.3. Then in .bashrc, add it to the PATH.

1 2	export RABBITMQ_HOME=/opt/rabbitmq_server-3.13.3 export PATH=$PATH:$RABBITMQ_HOME/sbin

Finally, you can enable RabbitMQ management plugin.

1	rabbitmq-plugins enable rabbitmq_management

2. Basic Use of RabbitMQ

2.1 Commands

Below are some common commands to start or stop RabbitMQ server.

rabbitmq-server           # run in the foreground
rabbitmq-server -detached # run in the background
rabbitmqctl status        # check service status
rabbitmqctl stop          # stop service

2.2 User management

You should have RabbitMQ server started to proceed any operations.

To access RabbitMQ management dashboard remotely, a new user must be created. Here we create a user and set it as Administrator.

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rabbitmqctl add_user <username> <password>
rabbitmqctl set_user_tags <username> administrator
rabbitmqctl set_permissions -p "/" <username> ".*" ".*" ".*"

We can check permissions of a user by this.

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rabbitmqctl list_users
rabbitmqctl list_user_permissions <username>
rabbitmqctl list_permissions -p /

You can change a user’s password like this.

1	rabbitmqctl change_password <usrname> <new password>

2.3 RabbitMQ dashboard

After adding an administrator, open port 15672 of your server and check the RabbitMQ dashboard! If you have it installed on your local machine, just visit it on localhost, which doesn’t require administrator privileges.

Once you have access to the dashboard, there’s no need for the CLI.

Adding exchanges and queues

Go to “Exchange” tab, and expand the section “Add a new exchange”. After submit, a new exchange will appear in the table above.

Then, go to “Queues and Streams” tab for the same thing.

When you have both exchange and queue, you can bind then bind them. Click the exchange to go to the detailed page, and add a binding.

Sending your first message

Below you can see the “Publish message” section where you can test message production.

You can see the message statistics in the overview tab or the details tab of specific queues.

Epilogue

Tada!🎊You have RabbitMQ up and running! In the following article, I’ll demonstrate how to integrate RabbitMQ into Spring Boot application. Coming soon.🙂

By the way, there’s some other stuff I want to talk about. First is the installation. I tried to use package management to install RabbitMQ, but it turned out to be a mess. The official setup script is long and will add many configurations to your system. And the installed server won’t start up due to unknown reasons.😖The best solution is indeed using a docker, but it’s not available on my machine, so I didn’t show that.

There are other AMQP implementations like Apache Kafka and RocketMQ, but RabbitMQ seems to be more popular? Anyway, you have RabbitMQ, enjoy. ᓚᘏᗢ