Actions

An action runs work and may return outputs. It has one Run method. It is implemented as an instance of the runtime.TypedAction[Out, Config any] interface.

The following is a runtime.TypedAction[*EchoOutput, runtime.NoConfig]:

type Echo struct {
    Text string
}

type EchoOutput struct {
    Text   string
    Length int64
}

func (e *Echo) Run(ctx context.Context, cfg runtime.NoConfig) (*EchoOutput, error) {
    return &EchoOutput{Text: e.Text, Length: int64(len(e.Text))}, nil
}

Register it:

Actions: map[string]runtime.ActionRegistration{
    "echo": runtime.MakeAction[Echo, *EchoOutput, runtime.NoConfig](),
}

A factory uses it under actions::

actions: {
  announce: util.echo {
    text: 'deploy complete'
  }
}

Triggers

@trigger is an action-only meta key. Without it, an action reruns when its evaluated inputs change. Set @trigger to a value that should decide reruns:

actions: {
  read-back: std.exec-command {
    @trigger: resource.file.sha256
    argv:     ['cat', input.path]
  }
}

Use @trigger: 'always' for an action that should run every apply.

Lock and timeout

@lock and @timeout can also apply to resources and data sources.

@lock serializes nodes that use the same lock name during apply:

@lock: 'kubectl'

@timeout sets a duration string for the resource, data source, or action:

@timeout: '30s'