This role installs and configures a Nomad cluster on Linux systems that use systemd. A few assumptions made by this role are that:

• Nomad will be installed inside of a Consul cluster
• Nomad servers will be separate from Nomad clients (this is the recommended way to deploy a Nomad in a production environment)
• (Optional) The Vault instance/cluster present is configured as per the official Nomad guides for Vault integration

The role has a few optional features locked behind boolean variables that act as 'feature-flags'. They are set to false by default. To enable them, simply set the relevant variable to 'true' and the 'feature-flag' will be enabled.

An example of this is the HashiCorp Vault integration, which is hidden behind the nomad_vault_enabled variable.

All role variables are documented in defaults/main.yml with comments explaining (and examples showing) their usage.

For the Ansible controller:

• The netaddr python package
• The unzip system package

For the target hosts/environment:

• Linux
• systemd
• Consul cluster
• (Optional) A Vault cluster with the PKI secrets engine enabled

If you do not already have a Consul cluster installed and configured, you can use my Ansible role for Consul to create one.

If you want to use consul-template, then you will also require that too - my Ansible role for consul-template will do this for you.

You can install both roles via ansible-galaxy like so:

ansible-galaxy install snoord.consul
ansible-galaxy install snoord.consul_template

The consul-template role installs a instantiated systemd service template for consul-template. The unit file will look a little like the following:

[Unit]
Description=consul-template for %I
Requires=network-online.target consul.service
After=network-online.target consul.service vault.service nomad.service

[Service]
ExecStart=/usr/local/bin/consul-template -config=/etc/consul-template.d/%I.hcl
ExecReload=/bin/kill -HUP $MAINPID
ExecStop=/bin/kill -INT $MAINPID
PIDFile=/run/consul-template-%I.pid
Restart=always
KillMode=process
KillSignal=SIGINT
RestartSec=60s
LimitNOFILE=4096
TimeoutSec=5

[Install]
WantedBy=multi-user.target

Notice the use of %I in the example? That allows for dynamically specifying a configuration file located in /etc/consul-template.d when starting the service. Using the example configuration file in this role (templates/ctpl.nomad.hcl.j2) along with the systemd unit file block above, you would execute the following command to enable and start the service:

$ sudo systemctl enable --now [email protected]

The following examples are the minimum configuration you would need to successfully run this role. It is assumed you have a working Consul cluster, and each node has a Consul agent running locally. Generate an actual encryption key for nomad_encrypt_string using nomad operator keygen, replacing "encryptme123" with the generated key in the examples below.

For a group of 3 Nomad server nodes:

- hosts: nomad-servers
  become: yes
  roles:
    - role: snoord.nomad
      vars:
        nomad_server: true #Setting this to true automatically sets `nomad_client` to false (unless otherwise specified)
        nomad_bootstrap_expect: 3
        nomad_encrypt_string: 'encryptme123='

For a group of Nomad client nodes:

- hosts: nomad-clients
  become: yes
  roles:
    - role: snoord.nomad
      vars:
        nomad_client: true #Assumed true by default, included here for clarity
        nomad_encrypt_string: 'encryptme123='

MIT / BSD

Created by Samuel Noordhuis in 2020. Inspired heavily by the Ansible roles and writings of Jeff Geerling.

If you see any errors or think this role could be improved in some way, you are welcome to open an issue/feature request or create a pull request :)