Legacy index template deprecation/migration UX

[cjcenizal]

Once legacy index templates are deprecated, users will need guidance on how to migrate them to the new composable index templates. The initial assistance we can offer is to document principles and manual steps users can take in our docs. Beyond that, we can provide UI and API tools for automating part of all of this process.

"Checklist" idea

One idea I had was to treat the UI as a "checklist" of legacy index templates to work through. I envision a workflow where the user goes through their legacy index templates, migrate them one-by-one or in bulk, and then hides the entire list of legacy index templates once it's empty. Being able to see how many have been migrated and how many remain will give the user a sense of progress through this workflow.

Clicking the "Upgrade" button above will show a progress spinner and then remove the index template from the v1 table and add it to the v2 table. Users could also select multiple index templates to perform a bulk migration.

Relationship with Upgrade Assistant

I was thinking we could surface the presence and count of legacy index templates in Upgrade Assistant, with a link to the above UI in Index Management, essentially directing the user to do their migration work there.

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[alisonelizabeth]

I was thinking we could surface the presence and count of legacy index templates in Upgrade Assistant, with a link to the above UI in Index Management, essentially directing the user to do their migration work there.

@cjcenizal is this something you'd still like to consider surfacing in UA?

[cjcenizal]

@alisonelizabeth I don't think we need to act on this yet, since legacy index templates haven't yet been slated for removal.

[alisonelizabeth]

I'm going to close this issue as not planned. Legacy index templates have been deprecated for quite awhile now.