Introduction to Nomad Pack

6min
|
Nomad

This guide will walk you through basic usage of Nomad Pack, a package manager and templating tool for Nomad.

By the end of this guide, you will know what Nomad Pack does, be able to deploy applications to Nomad using Nomad Pack, and discover packs built by the Nomad community.

What is Nomad Pack

Nomad Pack is a templating and packaging tool used with HashiCorp Nomad.

Nomad Pack is used to:

Easily deploy popular applications to Nomad
Re-use common patterns across internal applications
Find and share job specifications with the Nomad community

Nomad Pack can be thought of as a templating and deployment tool like Levant with the ability to pull from remote registries and deploy multiple resources together, like Helm.

Requirements

A Nomad cluster available
Nomad cluster address defined in the NOMAD_ADDR environment variable.

Note

If Nomad ACLs are enabled, a token with proper permissions must be defined in the NOMAD_TOKEN environment variable.

Installing Nomad Pack

To use Nomad Pack, download the binary for your system from HashiCorp Releases.

After downloading Nomad Pack, unzip the package, and make sure that the nomad-pack binary is available on your PATH.

Alternatively, you can install it with Homebrew if you are on MacOS.

$ brew tap hashicorp/tap
$ brew install hashicorp/tap/nomad-pack

You can now run nomad-pack.

Basic use

To get started, run the list command to see which packs are available to deploy.

$ nomad-pack list
          PACK NAME          | METADATA VERSION |                  REGISTRY NAME
-----------------------------+------------------+---------------------------------------------------
  alertmanager               | 0.0.1            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  aws_ebs_csi                | 0.1.0            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  aws_efs_csi                | 0.0.1            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  backstage                  | 0.0.1            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  boundary                   | 0.0.1            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  caddy                      | 0.0.1            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  ceph                       | 0.1.0            | default@6bac78a905b7966ed93078cba1604fafe0fa2334
  [...]

The first time you run the list command, Nomad Pack will add a nomad/packs directory to your desktop user's cache directory—$XDG_CACHE_DIR on Linux, ~/Library/Caches on macOS, %AppData% on Windows, etc. This folder stores information about cloned registries and their available packs.

During initializing, Nomad Pack downloads a default registry of packs from the Nomad Pack community registry.

To deploy one of these packs, use the run command. This deploys each job defined in the pack to Nomad. To deploy the hello_world pack, you would run the following command:

$ nomad-pack run hello_world

  Evaluation ID: 67835384-763b-62b0-7c41-eb98a5417e9c
  Job 'hello_world' in pack deployment 'hello_world@latest' registered successfully
Pack successfully deployed. Use --name=hello_world@latest to manage this this deployed instance with run, plan, or destroy

Congrats! You deployed a simple service on Nomad.

Note

The syntax for Nomad Pack is different in version 0.1. To run packs written with the old syntax, provide the --parser-v1 flag.

Each pack defines a set of variables that can be provided by the user. To get information on the pack and to see which variables can be passed in, run the info command.

$ nomad-pack info hello_world

Pack Name          hello_world
Description        This deploys a simple application as a service with an optional associated consul service.
Application URL    https://learn.hashicorp.com/tutorials/nomad/get-started-run?in=nomad/get-started
Application Author HashiCorp

Pack "hello_world" Variables:
  - "message" (string) - The message your application will render
  - "register_consul_service" (bool) - If you want to register a consul service for the job
  - "consul_service_name" (string) - The consul service name for the hello-world application
  - "consul_service_tags" (list of string) - The consul service name for the hello-world application
  - "job_name" (string) - The name to use as the job name which overrides using the pack name
  - "region" (string) - The region where jobs will be deployed
  - "datacenters" (list of string) - A list of datacenters in the region which are eligible for task placement
  - "count" (number) - The number of app instances to deploy

Values for these variables are provided using the --var flag. Update your pack using the following command:

$ nomad-pack run hello_world --var message=hola

Values can also be provided by passing in a variables file with the -f flag.

$ tee -a ./my-variables.hcl << END
message=bonjour
END

$ nomad-pack run hello_world -f ./my-variables.hcl

To see a list of deployed packs, run the status command

$ nomad-pack status

   PACK NAME  | REGISTRY NAME
--------------+----------------
  hello_world | default

To see the status of the jobs deployed by a pack, run the status command with the pack name.

$ nomad-pack status hello_world

   PACK NAME  | REGISTRY NAME |  DEPLOYMENT NAME   |  JOB NAME   | STATUS
--------------+---------------+--------------------+-------------+----------
  hello_world | default       | hello_world@latest | hello_world | pending

To remove all the resources deployed by a pack, run the destroy command with the pack name.

$ nomad-pack destroy hello_world

To stop the jobs without removing them from Nomad, use the stop command:

$ nomad-pack stop hello_world

Adding non-default Pack registries

When using Nomad Pack, the default registry for packs is the Nomad Pack Community Registry. Packs from this registry will be made automatically available.

You can add more registries by using the registry add command. For instance, if you want to add a registry from GitLab with the alias my_packs, you can run the following command to download the registry and its contents.

$ nomad-pack registry add my_packs gitlab.com/mikenomitch/pack-registry

go-getter URL is gitlab.com/mikenomitch/pack-registry
Registry successfully cloned at /Users/arusso/Library/Caches/nomad/packs/nomad-pack-tmp
Processing pack entries at /Users/arusso/Library/Caches/nomad/packs/nomad-pack-tmp
found pack entry fabio
Processing pack fabio@latest
Updating pack
Removing previous latest
Writing pack to /Users/arusso/Library/Caches/nomad/packs/my_packs/fabio@latest
Loading cloned pack from /Users/arusso/Library/Caches/nomad/packs/my_packs/fabio@latest
Calculating SHA for latest
found pack entry grafana
Processing pack grafana@latest
Updating pack
Removing previous latest
Writing pack to /Users/arusso/Library/Caches/nomad/packs/my_packs/grafana@latest
Loading cloned pack from /Users/arusso/Library/Caches/nomad/packs/my_packs/grafana@latest
Calculating SHA for latest
[...]
  Try running one the packs you just added liked this

    nomad-pack run fabio --registry=my_packs --ref=latest

To view the available registries, including yours, run the registry list command.

$ nomad-pack registry list
  REGISTRY NAME |  REF   | LOCAL REF |                    REGISTRY URL
----------------+--------+-----------+-----------------------------------------------------
  default       | latest | 6bac78a9  | github.com/hashicorp/nomad-pack-community-registry
  my_packs      | latest | 7ca313c7  | gitlab.com/mikenomitch/pack-registry

To view the available packs, including yours, run the list command.

$ nomad-pack list
[...]
  fabio                      | 0.0.1            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  grafana                    | 0.1.0            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  haproxy                    | 0.0.1            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  hello_world                | 0.0.1            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  loki                       | 0.0.1            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  nginx                      | 0.0.1            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  nomad_autoscaler           | 0.1.0            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334
  traefik                    | 0.1.0            | my_packs@7ca313c705b7966ed93078cba1604fafe0fa2334

You can deploy packs from this registry with the run command and the alias given to the registry, in this case my_packs.

$ nomad-pack run nginx --registry=my_packs
  Evaluation ID: aaa3c319-1928-7c35-54b0-2358841c0e96
  Job 'nginx' in pack deployment 'nginx@latest' registered successfully
Pack successfully deployed. Use nginx with --ref=latest to manage this this deployed instance with plan, stop, destroy, or info

Nginx successfully deployed.

See the Load Balancing with Nginx tutorial for more information:
https://learn.hashicorp.com/tutorials/nomad/load-balancing-nginx

Next steps

In this tutorial you learned what Nomad Pack does, how to deploy applications to Nomad using Nomad Pack, and how to discover packs built by the Nomad community.

Continue on to the Detailed Usage Tutorial for more detailed information about how to use Nomad Pack.

Go template syntax

Writing custom packs

This tutorial also appears in:

3 tutorials

Nomad Pack
Learn to use Nomad Pack, a package manager and templating tool for Nomad.
- Nomad