Upgrade PaaS to Solr8

[stooit]

• Use latest upstream solr8 images
• Use sane starting configuration from search_api_solr jumpstart

[tobybellwood]

Be aware that there is a gotcha here in Solr 8 - because the core config is now stored in the volume (and not the image), any changes to the config have to be reapplied to the core to take effect. The precreate-core command will exit if the config directory already exists, meaning that any updates don't get applied.

When I created the solr8 images, I added a solr-recreate command that removes the current core config and the re-adds it, ensuring it gets updated. See https://github.com/uselagoon/lagoon-images/pull/97

I'd encourage you to test this both ways, just to get a better understanding of how solr8 and beyond apply updates to solr config, and let me know if I've not covered it!

[stooit]

Thanks @tobybellwood -- we used precreate-core for the SaaS image seeing as we expect config to be locked with the defaults, but for PaaS it likely makes more sense to roll with solr-recreate since they may make config change.

Will do some further testing and add comments in the dockerfile and KB article so PaaS customers understand the difference here.

[tobybellwood]

perfect! Yes, figured SaaS was controlled.