Add support for maintainers

[ThorstenHans]

What does this change

This PR adds support for specifying maintainers in porter.yml.

maintainers:
- name: "John Doe"
  email: "john.doe@mail.com"
  url: "https://domain.com/a"
- name: "Jane Doe"
  url: "https://domain.com/b"
- name: "Janine Doe"
  email: "janine.doe@mail.com"
- email: "mike.doe@mail.com"
  url: "https://domain.com/c"

Generated CNAB bundle.json will contain specified maintainers.

Both - maintainers and the nested fields - are optional.

What issue does it fix

Closes #1559

Notes for the reviewer

Had to update the simple manifest digest in pkg/cnab/config-adapter/stamp_test.go.

[carolynvs]

I have retargeted this branch to the new v1 branch. Going forward from today (I just created it this morning), check if the issue is in the v1 milestone and if it is, create your feature branch based on the v1 branch so that you don't end up with merge conflicts because v1 and main are going to diverge quickly. 👍

[carolynvs]

Looking good! I just have some small questions.

[carolynvs]

• Can you help me understand why source is a pointer here?
• Also why is the returned maintainer entry a pointer?

[ThorstenHans]

Pointer makes no sense for source as the slice is passed by ref anyways.

For the return value, my intention was to prevent returning a new copy.

[carolynvs]

Since it is a small struct (3 strings) and doesn't make use of any pointer semantics (it doesn't modify its own data), the convention in Go is to usually pass back a copy anyway. The data will be allocated on the stack (instead of the heap) and the memory recovered without having to rely on garbage collection.

It's not a huge deal but it does help avoid nil pointer concerns and is easier to work with than pointers.

[carolynvs]

There is one more change to make in this PR. If you remember from the PR checklist one of the items is the schema. We have a jsonschema document for the porter.yaml. It lets us validate the porter.yaml contents and also give people autocomplete when they use editors like VS Code.

We need to update the jsonschema to include the new maintainers section. I wasn't sure if you are familiar with jsonschema so here is what the change would look like:

carolynvs@236e88a#diff-79f56eb4547c3a381285d1f26793b2cbd2e3d540e8783654511a91b4332eafd5

I have just added a magefile target that makes it easier to change the porter schema and fix the resulting tests that fail. Either rebase or merge the latest of main into your branch, and then you can then run mage updateTestfiles, it will update the tests with the new output of porter schema for you.

[ThorstenHans]

had to update my for to get the new target for mage. However, the commit cbd22dc (which is already on main)is not signed.

[carolynvs]

Don't worry about DCO bot messages for commits that aren't yours. It was actually one of my PRs that merged funny, it only took the title and didn't keep the commit message with the signoff. I can always verify manually and mark the PR as signed. 👍

[carolynvs]

Oops, when I asked you to rebase I said the wrong branch to rebase against. It should have been v1, which is why you are now seeing extra commits in your pull request. Sorry about that!

Here's how to fix it:

1. Get the latest changes on the v1 branch

   git fetch https://github.com/getporter/porter.git v1:v1
   

2. Rebase your branch on v1

   git checkout feature/maintainers
   git rebase -i v1
   

3. All of the commits that the rebase command shows you should be yours now. Save the file and let the rebase continue.
4. Now if you look at the log of your branch it should be all of your commits without the extras from main.
5. Push your changes back to your PR with a --force push.

[carolynvs]

If you run into trouble with the rebase, I'm happy to fix up the PR for you so that we can merge it.

[ThorstenHans]

there we go

[carolynvs]

Looks great, thanks!