Users hit a 404 when they try to access the old securing apps guide

[ahus1]

Describe the problem

A lot of external pages link to and see a 404 page:

/docs/latest/security_apps/
/docs/latest/security_apps/index.html

It seems that ~200 users per day are affected.

Similar to that it happens for this older guide:

/docs/latest/server_installation/
/docs/latest/server_installation/index.html

It seems that ~50 users per day are affected.

Expected behavior

There should be redirects. While a page based redirect could forward to the overview, a JavaScript based approach could analyze the anchor and then direct to the right page in the new securing guide.

How to Reproduce?

Open the old link.

Anything else?

Having a JavaScript based approach on the 404 page would provide a better response code to automatic crawlers compared to 200 with a meta redirect. AFAIK no other redirect techniques exist for GitHub pages.

A 404 page where to add the necessary JavaScript is now available here: https://github.com/keycloak/keycloak-web/blob/main/pages/404.ftl

It should be simple to add new redirect to the page with and without a hash/anchor.

[ahus1]

Additional thoughts: IMHO JavaScript based redirects is the way, as it can also handle removed (JavaDoc) API docs to redirect to the latest.

[ahus1]

Kudos to @mhajas who researched that this is mostly external sites linking to the Keycloak website / cc: @stianst

[ahus1]

Initial PR to handle the base functionality in #560

[ahus1]

Fist redirect support is available. Next iteration is to add redirects for each old chapter.