* cli: add -json flag to support job commands
While the CLI has always supported running JSON jobs, its support has
been via HCLv2's JSON parsing. I have no idea what format it expects the
job to be in, but it's absolutely not in the same format as the API
expects.
So I ignored that and added a new -json flag to explicitly support *API*
style JSON jobspecs.
The jobspecs can even have the wrapping {"Job": {...}} envelope or not!
* docs: fix example for `nomad job validate`
We haven't been able to validate inside driver config stanzas ever since
the move to task driver plugins. 😭
Fix a test corruption issue, where a test accidentally unsets
the `NOMAD_LICENSE` environment variable, that's relied on by some
tests.
As a habit, tests should always restore the environment variable value
on test completion. Golang 1.17 introduced
[`t.Setenv`](https://pkg.go.dev/testing#T.Setenv) to address this issue.
However, as 1.0.x and 1.1.x branches target golang 1.15 and 1.16, I
opted to use a helper function to ease backports.
Fixes a bug where if a command flag parsing errors, the resulting error
and help usage messages get interleaved in unexpected and non-user
friendly way.
The reason is that we have flag parsing library effectively writes to
ui.Error in a goroutine. This is problematic: first, we lose the sequencing between help
usage and error message; second, cli.Ui methods are not concurrent safe.
Here, we introduce a custom error writer that buffers result and calls
ui.Error() in the write method and in the same goroutine.
For context, we need to wrap ui.Error because it's line-oriented, while
flags library expects a io.Writer which is bytes oriented.
Michael Schurter