github.com/wallyworld/juju@v0.0.0-20161013125918-6cf1bc9d917a/worker/machineundertaker/manifold.go (about)

     1  // Copyright 2016 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package machineundertaker
     5  
     6  import (
     7  	"github.com/juju/errors"
     8  
     9  	"github.com/juju/juju/api/base"
    10  	"github.com/juju/juju/api/machineundertaker"
    11  	"github.com/juju/juju/api/watcher"
    12  	"github.com/juju/juju/environs"
    13  	"github.com/juju/juju/worker"
    14  	"github.com/juju/juju/worker/dependency"
    15  )
    16  
    17  // ManifoldConfig defines the machine undertaker's configuration and
    18  // dependencies.
    19  type ManifoldConfig struct {
    20  	APICallerName string
    21  	EnvironName   string
    22  
    23  	NewWorker func(Facade, environs.Environ) (worker.Worker, error)
    24  }
    25  
    26  // Manifold returns a dependency.Manifold that runs a machine
    27  // undertaker.
    28  func Manifold(config ManifoldConfig) dependency.Manifold {
    29  	return dependency.Manifold{
    30  		Inputs: []string{config.APICallerName, config.EnvironName},
    31  		Start: func(context dependency.Context) (worker.Worker, error) {
    32  			var apiCaller base.APICaller
    33  			if err := context.Get(config.APICallerName, &apiCaller); err != nil {
    34  				return nil, errors.Trace(err)
    35  			}
    36  			var environ environs.Environ
    37  			if err := context.Get(config.EnvironName, &environ); err != nil {
    38  				return nil, errors.Trace(err)
    39  			}
    40  			api, err := machineundertaker.NewAPI(apiCaller, watcher.NewNotifyWatcher)
    41  			if err != nil {
    42  				return nil, errors.Trace(err)
    43  			}
    44  			w, err := config.NewWorker(api, environ)
    45  			if err != nil {
    46  				return nil, errors.Trace(err)
    47  			}
    48  			return w, nil
    49  		},
    50  	}
    51  }