Installation

We will be installing Consul on each machine. We are using the latest Consul version as of this writing (0.6.4).

Download the consul program from the Consul project's page and follow the steps below:

Download the version corresponding to your operating system and architecture. In this guide, since we are using 64-bit servers, we will use the "amd64" link under "linux".

In your terminal, change your directory to /usr/local/bin, where we will keep the executable.

root@server1:~#cd /usr/local/bin

root@server1:~#wget https://releases.hashicorp.com/consul/0.6.4/consul_0.6.4_linux_amd64.zip

Now, we can extract the binary package and we can then remove the zipped file.

root@server1:~#unzip consul_0.6.4_linux_amd64.zip

root@server1:~#consul version
Consul v0.6.4
Consul Protocol: 3 (Understands back to: 1)

Repeat these steps on all your machines. You should now have the consul command available on all of your nodes.

Create the necessary directories

We can easily try out Consul in an unstructured way by using the consul command. This will allow you to test out some functionality and to get familiar with the software. But in a real world environment having an organized directory structure makes things easier to maintain. Complete the following steps on each of your servers and clients.

We will run Consul processes with a dedicated user.

Create the user:

root@server1:~#useradd -m consul

root@server1:~#passwd consul
Enter new UNIX password: consul
Retype new UNIX password: consul
passwd: password updated successfully

root@server1:~#usermod -aG sudo consul

We will next create the configuration directories where we can store Consul configuration. We will make a parent consul.d directory in /etc and create a subdirectory server for the server nodes and a client directory for the client node. We can put our configuration as a JSON file inside these directories. Having this structure is not mandatory but it helps to keep things organized.

root@server1:~#mkdir -p /etc/consul.d/server

We also need to create a location where Consul can store persistant data between reboots. We will create this directory at /var/consul and change its ownership to the consul user so that it can manage the data:

root@server1:~#mkdir /var/consul
root@server1:~#chown consul: /var/consul

All our directories are now in place, now we will create configuration files on each node under /etc/consul.d/server/

Before creating the configuration files we need to understand what is bootstrapping.