Env info rake task reports confusing Redis version for external Redis servers

Summary

Looking at a support ticket I realized that the Redis version reported by the gitlab:env:info rake task might be confusing.

The reported version is actually of the redis-cli version, not the server version, so for example an external redis server with a 3.0 version but using the Omnibus shipped Redis version will still show 3.2 (that's just an example for <12.7 as we now ship Redis 5)

Steps to reproduce

  1. Configure an external Redis with a different version than the Omnibus shipped one
  2. Run gitlab-rake gitlab:env:info

What is the current bug behavior?

The reported "Redis version" is different than the actual Redis server version

What is the expected correct behavior?

Seeing something a bit less confusing, either a specific "Redis Client version", or mentioning that an external Redis is configured.

Relevant logs and/or screenshots

[root@ip ~]# gitlab-rake gitlab:env:info
[...]
Redis Version: 3.2.12
[...]

Possible fixes

Maybe we should update the wording to say Redis client, or detect whether an external Redis is configured and say it's external if so. 🤔