Robust Plugin Bootstrap Process

[frankgreco]

Current Problem

Currently, there is no good way to load a plugin. A good example of this is the apiKey plugin that is shipped with Kanali. The following lines are from Kanali's Dockerfile.

RUN curl -O https://raw.githubusercontent.com/northwesternmutual/kanali-plugin-apikey/v1.2.0/plugin.go
RUN GOOS=`go env GOHOSTOS` GOARCH=`go env GOHOSTARCH` go build -buildmode=plugin -o apiKey_v1.2.0.so plugin.go

If this approach were taken for every plugin, a new Kanali image would be needed for each new plugin version. This is not ideal.

Proposed Solution

kanalictl follows the following pattern for its commands:

kanalictl [noun] [verb]

We can add a new noun, plugin and a new verb, load an example of this could be:

kanalictl plugin load --requirements=./plugins.yaml --location=/kanali/plugins

...and an example of a requirements file format:

---
plugins:
- name: apiKey
  version: v1.2.0
  location: github.com/northwesternmutual/kanali-plugin-apikey

kanali will load compiled plugins form a configurable location. Hence, this new command would do the following:

1. clone each repo as specified by each plugin in this plugins list
2. checkout the specified version
3. compile plugin -buildmode=plugin -o <name>_<version>.so
4. place .so file in specified --location

This solution solves the stated problem because:

1. plugin bootstrap is abstracted from the kanali image...and from any image
2. we can use a Kubernetes init container to bootstrap the plugins before the Kanali pod starts.