Handle fab set where 2+ matches exist in subpaths

[dtzar]

If there is more than one tag in a subpath, fab set should detect this, fail and display useful information so the user can fix the command.

For instance imageTag is present for multiple charts under the staging environment with a command like this: fab set --environment staging imageTag=foo:121

Fabrikate might fail and return something like this back in an error message: imageTag exists in multiple directories chart1.app1.imageTag chart2.app2.imageTag. Specify a set path which matches only one item.

This command would succeed: fab set --environment staging app1.imageTag=foo:121 app2.imageTag=bar:343

[timfpark]

fab set only applies its action to the current config directory, and in your case, the environment staging - so in this case, it would emit/set the following config:

config/staging.yaml: 

config:
  imageTag: "foo:121"

So in using fab you currently express at what level in the hierarchy you want the config to be applied in by executing it in that directory.