How to Install Consul Server on Ubuntu Linux

Prerequisites

• A machine running Ubuntu Linux (18.04 or later)
• Sudo privileges
• Stable internet connection for software download

Update System Packages

Open up your terminal and begin by updating your package lists:

sudo apt-get update

Then, upgrade your system packages to the latest versions:

sudo apt-get upgrade

Download Consul

To install Consul server on Ubuntu, you first need to download the Consul software. You can get the latest version directly from HashiCorp’s official website using a simple command.

First, install wget if you do not have it already:

sudo apt-get install wget unzip

Next, download the Consul zip archive. You can find the latest version from the link below:

Consul latest version

CONSUL_VERSION="1.17.2"
wget https://releases.hashicorp.com/consul/${CONSUL_VERSION}/consul_${CONSUL_VERSION}_linux_amd64.zip

Install Consul

After downloading Consul, the next step is to install it so your system can use it. This involves unzipping the downloaded file and placing the Consul program where your system can find it, making it ready to run.

unzip consul_${CONSUL_VERSION}_linux_amd64.zip

Move the Consul binary to your system’s PATH so that it can be executed from anywhere:

sudo mv consul /usr/local/bin/

Verify the installation:

consul --version

The command should output similar lines shown below;

Consul v1.17.2
Revision 7736539d
Build Date 2024-01-22T16:55:18Z
Protocol 2 spoken by default, understands 2 to 3 (agent will automatically use protocol >2 when speaking to compatible agents)

Create a Consul User

For security reasons, it’s best not to run Consul as root. Create a new user for Consul:

sudo useradd --system --home /etc/consul.d --shell /bin/false consul

Configure Consul

Now that Consul is installed, you need to set up its configuration. This involves creating specific folders where Consul will store its settings and then making sure the Consul program has permission to use them.

sudo mkdir --parents /opt/consul
sudo mkdir --parents /etc/consul.d

Grant the Consul user ownership of those directories:

sudo chown --recursive consul:consul /opt/consul
sudo chown --recursive consul:consul /etc/consul.d

Create a basic configuration file by running the command below.

sudo nano /etc/consul.d/consul.hcl

Then, please copy and paste the content below into the file and save it. Remember to replace the bind_addr and advertise_addr addresses with your server’s own.

{
  "datacenter": "dc1",
  "data_dir": "/opt/consul",
  "log_level": "INFO",
  "server": true,
  "ui": true,
  "bind_addr": "192.168.128.2",
  "client_addr": "0.0.0.0",
  "advertise_addr": "192.168.128.2",
  "bootstrap_expect": 1
}

Create a Systemd Service File

To make sure Consul runs smoothly in the background and starts automatically, you’ll create a systemd service file. This file tells your Ubuntu system how to manage the Consul process, like starting and stopping it.

sudo nano /etc/systemd/system/consul.service

Then, please copy and paste the content below into the file and save it.

[Unit]
Description=Consul Service
After=network.target

[Service]
User=consul
Group=consul
ExecStart=/usr/local/bin/consul agent -config-dir=/etc/consul.d/
ExecReload=/bin/kill -HUP $MAINPID
KillMode=process
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

Next, reload the systemd daemon and enable the Consul service to run on system boot:

sudo systemctl daemon-reload
sudo systemctl enable consul

Start and Verify the Consul Service

With the service file ready, you can now start the Consul server and check if it’s running correctly. This step confirms that Consul is active and ready to go on your Ubuntu machine.

sudo systemctl start consul

Check the status of the service:

sudo systemctl status consul

You should see similar lines as shown below.

 consul.service - Consul Service
     Loaded: loaded (/etc/systemd/system/consul.service; enabled; preset: enabled)
     Active: active (running) since Fri 2024-01-26 08:17:23 CST; 1min 43s ago
   Main PID: 9990 (consul)
      Tasks: 8 (limit: 4571)
     Memory: 25.9M
        CPU: 1.255s
     CGroup: /system.slice/consul.service
             └─9990 /usr/local/bin/consul agent -config-dir=/etc/consul.d/

Access the Consul Web UI

Once Consul is running, you can easily check its status and manage it through a handy web interface. Simply open your web browser and go to a specific address using your Ubuntu machine’s IP address to see the Consul UI.

http://<Your_Ubuntu_Machine_IP>:8500/ui/

That should do it!

Conclusion:

• Consul by HashiCorp is a powerful tool for managing microservices, service meshes, and distributed systems. It provides automated network configurations, service discovery, and secure connectivity across any cloud or runtime environment.
• Following the installation guide, you have successfully installed Consul on your Ubuntu server. This allows you to organize services, manage dependencies, and automate common networking tasks.
• With Consul’s intuitive web UI and robust features, you are now ready to join other nodes to your cluster, configure service discovery, and set up service meshes to meet your organization’s specific requirements.