Juju Quick Start

These instructions will help you deploy your first charm with Juju to a MAAS cluster.

In the following, we assume that you have a MAAS cluster set-up with at least 2 nodes enlisted with it.

Your API key, SSH key, and environments.yaml

You'll need an API key from MAAS so that the Juju client can access it. Each user account in MAAS can have as many API keys as desired. One hard and fast rule is that you'll need to use a different API key for each Juju environment you set up within a single MAAS cluster.

There is no need to explicitly add an SSH key to MAAS when using Juju; it will automatically put your public key on any hosts that it starts up.

Note: You do not need to use the MAAS web UI or API to allocate a node to yourself, Juju will do this for you.

Getting a key

To get the API key:

1. Go to your MAAS preferences page (go to your MAAS home page http://${my-maas-server}:80/MAAS/ and choose Preferences from the drop-down menu that appears when clicking your username at the top-right of the page).
2. Optionally add a new MAAS key. Do this if you're setting up another environment within the same MAAS cluster.

The ${my-maas-server} slot should be replaced with the hostname of your MAAS server.

Adding an SSH key

While you're still on the MAAS preferences page, add your SSH key by clicking Add SSH key. Use the public half of your SSH key, the content of ~/.ssh/id_rsa.pub for example; don't paste the private half.

Creating environments.yaml

Create or modify ~/.juju/environments.yaml with the following content:

environments:
  maas:
    type: maas
    maas-server: 'http://${my-maas-server}:80/MAAS'
    maas-oauth: '${maas-api-key}'
    admin-secret: ${your-admin-secret}
    default-series: precise

Substitute the API key from earlier into the ${maas-api-key} slot, and the hostname of your MAAS server into the ${my-maas-server} slot.

The ${your-admin-secret} slot should be replaced with a random pass-phrase, there is no default.

Now Juju

If juju-core is not yet installed on the client machine, run:

sudo apt-get install juju-core

Now, use juju to display the status of the default environment:

juju status

As you've not bootstrapped you ought to see:

error: Unable to connect to environment "".
Please check your credentials or use 'juju bootstrap' to create a new environment.

Note: if Juju complains that there are multiple environments and no explicit default, add -e ${environment-name} after each command, e.g.:

juju status -e maas

Bootstrap:

juju sync-tools
juju bootstrap

If bootstrapping on a version of juju older than 1.14.0 then use:

juju bootstrap --upload-tools

This will return quickly, but the master node may take a long time to come up. It has to completely install Ubuntu and Juju on it and reboot before it'll be available for use. It's probably worth either trying a juju status once in a while to check on progress, or following the install on the node directly.

Once the boostrap node has been installed a status command should come up with something a bit more interesting:

environment: maas
   machines:
     "0":
       agent-state: started
       agent-version: 1.13.3.1
       dns-name: kmhwd.master
       instance-id: /MAAS/api/1.0/nodes/node-5c5b713a-1afc-11e3-9904-525400123456/
       series: precise
   services: {}

Now it's possible to deploy a charm:

juju deploy mysql
juju status

If you have another node free you can finish off the canonical and by now familiar example:

juju deploy wordpress
juju add-relation wordpress mysql
juju expose wordpress
juju status

Note that each charm runs on its own host, so each deployment will actually take as long as it took to bootstrap. Have a beer, drown your sorrows in liquor, or, my preference, have another cup of tea.