Enable redirects from JScholarship to Hopkins Digital Repository

[birkland]

Some records from JScholarship will be migrated to Hopkins Digital Repository (HDR) as part of the launch process. Whenever a user follows a URL to a migrated record in JScholarship, we want them to be redirected to the record in HDR instead. At a high level, we were thinking it would be sufficient to:

• Generate a map of JScholarship URLs to HDR URLs
• Configure the apache proxy for JScholarship to use RewriteMap to redirect only those URLs that represent migrated resources.

Doing this involves:

• [x] Verify that RewriteMap directives in Jscholarship's Apache proxy are a suitable way to implement redirects
• [x] Determine a way to generate the mapping of JScholarship URLs to HDR citable URLs (suggestion from @bseeger: use metadata export to get a CSV that has all data necessary for generating such a map). Involves parsing some output from HDR, and generating a map in the right format that RewriteMap expects
• [ ] Create a mapping and deploy it in JScholarship's apache

[bseeger]

@little9 created this PR - I'll review it today.

[little9]

@htpvu @bseeger the PR for the export that Apache will use has been merged. I think that the last task on this ticket should wait until folks want to start redirecting on JScholarship prod after the initial content ingest is complete.

If we want to close this ticket: I've tested that last task on JScholarship's stage environment. If this ticket gets closed we'll need to open another one with a task to deploy the full redirect export to production.