Expose workdir parameter to shell resource

[olblak]

• Handle command error
• Expose workdir parameter to shell resource

This pullrequest allows to specify a custom working directory from where to execute the shell command.
This parameter is needed as part of the autodiscovery feature link.

If spec.workdir is unset then nothing change compared to today
if spec.workdir is a relative path, then we join the current path with spec.workdir value
if spec.workir is an absolute path, then it overrides the current path (scm or not)

Signed-off-by: Olblak me@olblak.com

Test

To test this pull request, you can run the following commands:

cd pkg/plugins/resources/shell
go test .
go build -o bin/updatecli .
./bin/updatecli diff --config e2e/updatecli.d/success.d/shell/workDir.yaml

Additional Information

Tradeoff

In this pullrequest I also noticed that the function func (s *Shell) executeCommand(inputCmd command) didn't handle error which was a bit confusing to me why so I added that support.

Potential improvement

/

[olblak]

I am merging this PR now as I need it for #1065 and it doesn't change the current behavior
I am fine renaming workdir to something else until we release 0.44.0 which shouldn't happen until FOSDEM
Once 0.44.0 is released, it would need to be deprecated