Portworx on Nomad

This section covers information on installing Portworx on Nomad.

Nomad is a scheduler and job orchestrator from HashiCorp for managing a cluster of machines and running applications on them. Nomad abstracts away machines and the location of applications, and instead enables users to declare what they want to run and Nomad handles where they should run and how to run them. Portworx can run within Nomad and provide persistent volumes to other applications running on Nomad. This section describes how to deploy and consume Portworx within a Nomad cluster.

Install

Portworx can install easily through either Terraform or Ansible.

• To install with Terraform, please use the Terraform Portworx Module
• To install with Ansible, please use the Ansible Galaxy Role

Nomad has a very natural alignment with consul. Therefore having Portworx use consul as the clustered kvdb when deployed through Nomad makes common sense.
When doing so, consul can be referenced locally on all nodes, as with 127.0.0.1:8500

Hashi-porx

As a community resource, please refer to the hashi-porx repository for a full-stack deployment of consul, nomad, vault, the Hashi UI, and Portworx all deployed through Terraform on AWS.

When using the hashi-porx stack, the status for the Nomad and Consul clusters can be accessed through the GUI via the nomad_url output variable, which refers to port 3000 of the external load balancer.

Scaling

A Portworx cluster is uniquely defined by its kvdb and clusterID parameters. As long as these are consistent, a cluster can easily scale up in Terraform, by using the same kvdb and clusterID, and then increasing the instance count. Similarly for Ansible, as long as the same kvdb and clusterID are used, any new nodes can automatically join an existing cluster. (NB: For Ansible, be sure to exclude existing nodes from the inventory before running the playbook on the new nodes)

Upgrade

Currently for Nomad, Portworx needs to be upgraded through the CLI on a node-by-node basis. Please see the upgrade instructions

Using and Accessing Portworx

Portworx volumes can be easily accessed through the Nomad docker driver by referencing the pxd volume driver.

   ...
   task "mysql-server" {
      driver = "docker"
      config {
        image = "mysql/mysql-server:8.0"
        port_map {
          db = 3306
        }
        volumes = [
          "name=mysql,size=10,repl=3/:/var/lib/mysql",
        ]
        volume_driver = "pxd"
    }
    ...

A complete example for launching MySQL can be found here

Storage On Demand

Portworx provides an important feature that enables applications to have storage provisioned on demand, rather than requiring storage to be pre-provisioned.

The feature, is also referred to as inline volume creation . For more information, click here and see the section Inline volume spec.

Using this feature can be seen in the above example in the volumes clause. Note than all relevent Portworx volume metadata can be specified through this mechanism.