Currently, it is not possible to use solr on platform.sh.
Basically, we set shards settings, where the hostname doesn't resolve inside the solr container at platform.sh.
Solution is either
- Platform.sh may fix this by ensuring hostname provided by $PLATFORM_RELATIONSHIPS resolves in the solr container too, not only in the app container
- Change ezplatform to not set these shard settings on a single-solr setup