How to write a new plugin?

If you want to add a custom plugin in SkyWalking Satellite, the following contents would guide you. Let’s use memory-queue as an example of how to write a plugin.

  1. Choose the plugin category. As the memory-queue is a queue, the plugin should be written in the skywalking-satellite/plugins/queue directory. So we create a new directory called memory as the plugin codes space.

  2. Implement the interface in the skywalking-satellite/plugins/queue/api. Each plugin has 3 common methods, which are Name(), Description(), DefaultConfig().

    • Name() returns the unique name in the plugin category.
    • Description() returns the description of the plugin, which would be used to generate the plugin documentation.
    • DefaultConfig() returns the default plugin config with yaml pattern, which would be used as the default value in the plugin struct and to generate the plugin documentation.
    type Queue struct {
        config.CommonFields
        // config
        EventBufferSize int `mapstructure:"event_buffer_size"` // The maximum buffer event size.
       
        // components
        buffer *goconcurrentqueue.FixedFIFO
    }
       
    func (q *Queue) Name() string {
        return Name
    }
       
    func (q *Queue) Description() string {
        return "this is a memory queue to buffer the input event."
    }
       
    func (q *Queue) DefaultConfig() string {
        return `
    # The maximum buffer event size.
    event_buffer_size: 5000
    
  3. Add unit test.

  4. Generate the plugin docs.

make check