WIP: GRPC/Container Based Render Plugin supports

[lunny]

Feature Description

Original Implementation Drawbacks

Gitea support render plugin based on OS process for many years. The render plugin system has some drawbacks.

• The third-party software has to be installed on the same machine, so users have to create their own Dockerfile based on the official one.
• It's not out-of-box, users need to configure it themselves and restart Gitea after the configuration.
• It's difficult to be shared.

The New Implementation

This proposal introduce a new type render plugins which based on GRPC/WebSocket and container. Every plugin is a conatiner image which is also a RGPC client. It will connect to Gitea Server and registered as a special format render. It can register one or more extend names, like .md, .mdx and etc. After registered, it will be blocked to wait render task. If it got a render task, it will render the given special format content and return the HTML.

There are two different possible resultions.

• Run the render plugin as actions services on some container runner
• It will not depend on actions but have a standalone system, then it will have a default running container type. It could be docker, k8s.
  For the plugins, it can be running on local docker or remote k8s. Then when installing a plugin from the marketplace, using different method to download the image and run it and configure it.

TBC

[delvh]

Duplicate of #20126?

[lunny]

Common Plugin is a big topic which is not easy to implement. This is only for a renderer plugin based on container and GRPC.