Fixes https://pagure.io/pagure/issue/378

Maybe remark that you will not have the features they provide?

s/secondg/second/

I think it would be good to have a REDIS_WEBHOOK_DB and REDIS_ESS_DB, so people can use a different one per service?
Maybe even make the _HOST and _PORT per service to allow for more redundancy/flexibility.

Isn't that a little over the top?

I mean the idea is interesting, but the usage of redis by pagure currently is such that I'm not sure the flexibility gain is worth the effort/complexity this adds to the config file.

After reading the docs, only making REDIS_DB changeable would make no sense at all since pub/sub goes across databases.

Perhaps it would be an idea to prefix the pub-sub topics into something like pagure.issue.projectA.idX, pagure.pr.projectB.idY and pagure.hook, to make sure the same redis server doesn't need to be unique to Pagure?

Maybe even, as suggested in Redis documentation, pagure.production.*?

Since you're changing everything anyway, this would be a great moment to make this change.

Perhaps rename this function?
In this case, it doesn't handle a client but instead handles webhook requests/triggers.

Looks good to me. :thumbsup:

Thanks!