Rework the artifacts proxy to operate within Pages group domains

When -artifacts-server is enabled, we now proxy requests with paths of the following form to the GitLab API:

group.gitlab.io/-/subgroup/project/-/jobs/1/artifacts/index.html

Closes #83 (closed)

/cc @naysayer1 I thought you might be interested to see what circumstances are forcing on us ^^

It turns out that only safari copes with domains like artifacts~1~2.gitlab.io

@ayufan can you review?

assigned to @ayufan

@ayufan there's another possibility for the path, which I hadn't considered before.

• group.gitlab.io/-/subgroup/project/-/jobs/1/artifacts/index.html
• group.gitlab.io/-/project/-/jobs/1/artifacts/index.html

It doesn't really have any advantages over the current scheme except that it allows the subgroups and project to go together, instead of them being separated as they are now (e.g., group.gitlab.io/subgroup/-/project/jobs/1/artifacts/index.html

Let me know if you'd like this to change.

resolved all discussions

If we're to keep the existing scheme, maybe we should make the URL even longer:

mytoplevelgroup.gitlab.io/mysubgroup/-/projects/myproject/jobs/1/artifacts/index.html

Otherwise, we're storing up problems for when we want to add more functionality of this nature after the /-/.

mentioned in issue #83 (closed)

changed the description

Generally, there's quite an amount of changes. I just have two questions more, than something to complain. Please let me know what do you think @nick.thomas

@ayufan OK, addressed and ready for review again.

resolved all discussions

merged