Validate preconditions and show user-friendly messages

[kmaehashi]

Description

We have been actively utilizing the migration tool for shifting repositories from GHES to GHEC. The tool has been serving us well, and we are grateful for its convenience.

However, we often face complications arising from preparation mistakes (especially PATs). These issues often result in migration failure and require additional troubleshooting.

Currently, we are using a wrapper tool for the gh gei command to check pre-conditions as follows:

• The source organization and repository exists
• The source PAT has a valid set of OAuth scopes
• The source PAT has enough permission to generate migration archive in the organization
• The destination organization exists
• The destination repository DOES NOT exist
• The destination PAT has a valid set of OAuth scopes

• The destination PAT has enough permission to start migration to the organization

  To streamline the process, it would be great if the tool runs the pre-condition check first before starting the migration process and provides a user-friendly error message when the check failed.

[timrogers]

@kmaehashi Thanks for taking the time to reach out ❤️ I definitely agree with you that validations are crucial and can add a huge amount of value.

I believe that we already have most - although maybe not all - of these validations. I'll have to do some detailed digging to figure out the gaps.

Would you be willing to share the source of your wrapper tool? I'd love to take a look. Feel free to email me at timrogers@github.com if you don't want to share publicly.

[dylan-smith]

Currently the only fail fast explicit checks we do (for GHES sources) are that the target repo does not exist and the target org does exist.

The GEI API calls will do some more checks but that won't happen until after archive generation is complete.

[timrogers]

@dylan-smith Thanks! Good point on the GHES thing - I was thinking about the GHEC flow where we benefit earlier from the GitHub API's checks. I definitely think we could benefit from more checks in the CLI.

[kmaehashi]

Hi @timrogers, I've just shared the details via email. Hope this helps! 🙂