Versions and completions

[displague]

Description

• Fixes testing via Makefile make test (did not test anything before)
• Fixes Add version subcommand #94 based on the git SHA and eventual git tags (blocked by Cut release tags from tink #74)
  • Adds tink-cli --version output
  • Because tink-server and tink-worker do not currently take parameters, the version is now emitted at start.
    • tink-server emits this at INFO level (because it is a long-lived process)
    • tink-worker emits this at DEBUG level (because the default run is quiet, afaict)
• Adds a tink-cli completion subcommand

Why is this needed

Fixes: #94

How Has This Been Tested?

• tink-cli completion --help
• tink-cli completion bash

•  cmd/tink-cli/tink-cli --version
   tink version f9500b2
  

•  PACKET_VERSION="x" PACKET_ENV="t" ROLLBAR_TOKEN="t" cmd/tink-server/tink-server 
   {"level":"info","ts":1597460174.581983,"caller":"tink-server/main.go:30","msg":"starting version f9500b2","service":"github.com/tinkerbell/tink"}
   {"level":"info","ts":1597460174.582356,"caller":"metrics/metrics.go:58","msg":"initializing label values","service":"github.com/tinkerbell/tink"}
  

•  TINKERBELL_CERT_URL="l" PACKET_VERSION="x" PACKET_ENV="t" ROLLBAR_TOKEN="t" WORKER_LOG_LEVEL=debug cmd/tink-worker/tink-worker
   DEBU[0000] Starting version f9500b2                     
   INFO[0000] RETRY_INTERVAL not set. Using default, 3 seconds 
   INFO[0000] MAX_RETRY not set. Using default, 3 retries. 
   FATA[0000] fetch cert: Get "l": unsupported protocol scheme ""
  

How are existing users impacted? What migration steps/scripts do we need?

Checklist:

I have:

• updated the documentation and/or roadmap (if required)
• added unit or e2e tests
• provided instructions on how to upgrade

[gianarb]

Great, but I would like to get the documentation updated about how to setup completion as part of this work.

@DailyAlice can help to find a good place for that I think.

PR is great! Thank you for taking care of it

[displague]

@gianarb I can move completions to another PR and rebase either this PR or that one after merge.

If it helps, I can create a markdown and/or man-page generation process here. packet-cli performs a similar step using spf13/cobra. I can add this as a separate PR.

https://github.com/packethost/packet-cli/tree/master/docs is generated on each make invocation and commits must include docs/ without build jitter. What are your thoughts, @DailyAlice?

[gianarb]

I don't understand @displague . I think we should just write somewhere how to set up completion
https://kubernetes.io/docs/tasks/tools/install-kubectl/#enabling-shell-autocompletion

[gianarb]

It looks like documentation is on hold for now. This is good to go!