Ning Sun

This change introduces `git` as build dependency. Docker image for build needs to be updated

Typically we don't expose MQTT directly to IoT devices because that layer has its own authentication, data validation and device management business logic. In most case we need to bridge...

@killme2008 we need to decouple authentication and privilege system, in authentication we need - authentication on mysql/pg username/password - compile-time configurable/plug-able authentication source support - system tables as one of...

More on mysql and postgres ssl configuration: https://dev.mysql.com/doc/refman/5.7/en/using-encrypted-connections.html https://www.percona.com/blog/enabling-and-enforcing-ssl-tls-for-postgresql-connections/

@SSebo Is ssl supported in those client libraries we are using for testing? Using `mysql-client` for testing will add more dependencies in our build and CI requirements, which is not...

@SSebo perhaps we can reject the client by checking its ssl state in startup handler. When the client sends its `Startup` message to server, we can reply with error. I...

@SSebo I confirmed postgres enforces this check when handling `Startup` message. So we can do it in `on_startup` callback of pgwire's auth handler This is how postgresql receives startup message...

@SSebo I realized that `opensrv-mysql` and `pgwire` may provide different level of abstraction. `pgwire` expose `on_startup` to developer to customize this behaviour, while `opensrv-mysql` does not expose this startup apis....

@SSebo Look almost good to me! Please check these two minor comments. @MichaelScofield Please take a look as well. Thank you!

Congratulations! Thanks for your effort! This is a big step for enabling greptimedb in shared environment.