Base for machine resource

[hmlanigan]

Description

There are two parts. One separate the concerns of the terraform provider from the internal juju code which uses the juju api.

Two, add Base to the schema for machines, while deprecating Series. Regardless of which is supplied by the user, a base will be provided to the AddMachine api call to juju.

A string validator to cover Bases is also added, its used by machine and will be used for application as well.

Part of the effort to replace Series with Base within the terraform plans for juju as seen in #249

Type of change

• Change existing resource

QA steps

Here is a plan to test the change. Please set manual machines as well, to ensure no changes there.

provider juju {}

resource "juju_model" "testmodel" {
  name = "machinetest"
}

resource "juju_machine" "my-machine" {
  model = juju_model.testmodel.name
  base = "[email protected]"
}

[cderici]

Code looks good. QA looks good. One interesting observation was that destroying machines seems to taking a bit long when it (correctly) errors, at first I thought we weren't destroying, but then the machine disappeared from the status:

I created a machine with

resource "juju_machine" "my-machine2" {
  model = juju_model.testmodel.name
  // base = "[email protected]"
}

Then added a base, which was good.

Then changed the base to something wrong like ubuntu@15, which prompts recreate in the plan. It does correctly points out the error coming from the api for the second step (i.e. create). It's not super clear that the first step (i.e. destroy) is happening. Then while I was writing this message the machine disappeared suddenly (I was "watch"ing the sttatus).

Just a weird observation fyi, the PR is good to go 👍