I am also using Search API and Drupal 7. The only answer here isn't working for me as of 2024. I still get The Solr server could not be reached. Further data is therefore unavailable. with the recommended configuration.

I think the Solr host needs to be something that's accessible from inside the Docker container, and <projectname>.ddev.local -- I believe -- is not?

All I need for the Drupal 7 confiuration is protocol, host, port, and path for the solr server. I can't figure out what these values should be :(

I wasn't able to find any search_api or Drupal specific configuration on https://ddev.readthedocs.io/en/stable/users/extend/additional-services as per the 2019 comment - I expect things have moved since then :)

On that page there is an add-on named ddev/ddev-drupal-solr but all the notes on that say to consider using ddev/ddev-solr first (this is the one I am using), but the ddev/ddev-solr project is not one of the "Officially-supported add-ons" (whereas, the Drupal specific one is). I wonder if I should switch to ddev/ddev-drupal-solr instead?

I ran a search on ddev.readthedocs.io for search_api since I assume the former documentation was probably moved to another page, but the docs site only returns No matching documents. I also searched for "Search API" but though that returns a LOT of pages, none seem to be relevant to setting up the Drupal module.

Finding nothing in the Ddev docs, I did a google search for ddev/ddev-solr and was brought to the GitHub project for the addon, where there does appear to be some documentation for Search API and Drupal - though this closer to what I need -- it is still not relevant for Drupal 7 projects.

Just for funzies, I attempted to use the protocol, host, port, and path from the Solarium PHP client section, but alas, that does not appear to work when provided to the Drupal 7 module. :(

I'm going to switch to https://github.com/ddev/ddev-drupal-solr next and will report back if I can get that working.