`terraform_version` is not downloaded when using custom workflow

[maximede]

Following #639

It looks like when you specify a specific terraform version in terraform_version and use a custom workflow, the requested terraform binary will not be downloaded/available for the custom workflow

[lkysow]

Yes, if you don't use any built-in steps, ex - init, then it won't download the version for you. It's a bug.

[maximede]

@lkysow I might have a bit of time to work on this issue. I'm not completely sure how I should fix that.
Should I create a new built-in step that'd would just download the requested terraform version or should it be something smarter than that in the RUN step ?

[lkysow]

• I would make a public method on TerraformClient like EnsureVersion(log *logging.SimpleLogger, v *version.Version)
• in its implementation I would call the internal ensureVersion method
• Then in the RunStepRunner I would pass in TerraformClient and then call the method

[maximede]

That makes sense.
I'll submit a PR soon-ish