Can use toolsmiths-env metadata

[rowanjacobs]

What is this change about?

This PR adds a new toolsmiths-env input to many of the tasks relying on bbl state (specifically, to tasks which do not run bbl commands other than print-env and which are not involved with cleaning up an environment. The bbl-state input is now optional, although the tasks will error if neither input is provided. When the toolsmiths-env input is provided, the new --file flag will be provided to bbl print-env, which will read desired environment variables from the Toolsmiths environments app metadata file.

This is necessary for users of Toolsmiths cf-deployment environments to be able to use cf-deployment-concourse-tasks, since the Toolsmiths environments app does not provide users with a full bbl state.

Please provide contextual information.

This depends on this PR being merged.

Related Tracker stories:

• Modify bbl print-env to take metadata as input instead of bbl.state
• Update concourse tasks repo to use our new bbl flag

Related Slack thread (unfortunately most of the actual discussion of this was done over video and unrecorded)

Please check all that apply for this PR:

• [ ] introduces a new task
• [x] changes an existing task
• [ ] changes the Dockerfile
• [ ] introduces a breaking change (other users will need to make manual changes when this is released)

Did you update the README as appropriate for this change?

• [ ] YES
• [x] N/A

How should this change be described in release notes?

Allow users to specify Toolsmiths' metadata instead of bbl state when targeting environments.

What is the level of urgency for publishing this change?

• [x] Urgent - unblocks current or future work
• [ ] Slightly Less than Urgent

Tag your pair, your PM, and/or team!

cc @nhsieh @cloudfoundry/pcf-toolsmiths

[cf-gitbot]

We have created an issue in Pivotal Tracker to manage this:

https://www.pivotaltracker.com/story/show/169854870

The labels on this github issue will be updated when the story is started.

[linux-foundation-easycla[bot]]

The committers are authorized under a signed CLA.

• :white_check_mark: Nancy Hsieh (c2e5da85371f53b97f0bd50cc5683a147a206fda)
• :white_check_mark: Rowan Jacobs (3db768e5508f93492197c5ed384cd9a2055265d7)