Fix issue "redis" engine is not registered

[greedy52]

Error when connecting Redis database

Original Error: *trace.NotFoundError database engine "redis" is not registered

Related PR

• Add extra database validations to CreateDatabase #18776

(interestingly, this is not caught by test, likely because test has different importing path)

[smallinsky]

Does the init call was for redis engine in previous version was called from https://github.com/gravitational/teleport/pull/18776/files#diff-054e31280a78f4aea4759cd740f8d8bcecf563679d7fe6b79991fdb944e8c611L64 ?

LGTM to me though I think that we should clean when and how our db engines are registered to prevent this to happen again.

[greedy52]

Does the init call was for redis engine in previous version was called from

Yes. We were calling redis.ParseRedisAddress before so the redis lib gets implicitly inited. With that change, the new connection.ParseRedisAddress is used instead so we have to explicitly import the lib now.

LGTM to me though I think that we should clean when and how our db engines are registered to prevent this to happen again.

Agreed. The test didn't catch the problem as the test has to import redis for other setups. Need to ensure this won't happen again. How about checking if every engine type is registered at server start(or New)?

[smallinsky]

Agreed. The test didn't catch the problem as the test has to import redis for other setups. Need to ensure this won't happen again. How about checking if every engine type is registered at server start(or New)?

Yes that will work but I wonder if we can be more explict and insteam of calling _ db/engine/import we can just init everything from one place like:

// db/server.go
func init() {
  common.RegisterEngine(redis.NewEngine, defaults.ProtocolRedis)
  common.RegisterEngine(msql.NewEngine, defaults.ProtocolMySQL)
}

and makes things more readable.

[greedy52]

Yes that will work but I wonder if we can be more explict and insteam of calling _ db/engine/import we can just init everything from one place like:

// db/server.go
func init() {
  common.RegisterEngine(redis.NewEngine, defaults.ProtocolRedis)
  common.RegisterEngine(msql.NewEngine, defaults.ProtocolMySQL)
}

and makes things more readable.

@smallinsky really like that. Will do that separately. The test registers fake engine in init() so need to make sure the ordering.

[github-actions]

@greedy52 See the table below for backport results.

Branch	Result
branch/v11	Failed