In pkg/helpers.go the RunCommand function uses cmd.CombinedOutput. I am wondering why this was chosen instead of cmd.Output.
An issue with it is that when the container engines sends warnings they are added to the result sent to the standard output and this for instance cannot be unmarshaled from json in: if err := json.Unmarshal(output, &dockerInspect); err != nil { of the same file.
This resulted in the following error message:
unable to inspect the index image: invalid character 'i' in literal true (expecting 'r')