github.com/makyo/juju@v0.0.0-20160425123129-2608902037e9/worker/instancepoller/manifold.go (about)

     1  // Copyright 2015 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package instancepoller
     5  
     6  import (
     7  	"github.com/juju/errors"
     8  
     9  	"github.com/juju/juju/api/base"
    10  	"github.com/juju/juju/api/instancepoller"
    11  	"github.com/juju/juju/environs"
    12  	"github.com/juju/juju/worker"
    13  	"github.com/juju/juju/worker/dependency"
    14  )
    15  
    16  // ManifoldConfig describes the resources used by the instancepoller worker.
    17  type ManifoldConfig struct {
    18  	APICallerName string
    19  	EnvironName   string
    20  }
    21  
    22  func (config ManifoldConfig) start(context dependency.Context) (worker.Worker, error) {
    23  	var environ environs.Environ
    24  	if err := context.Get(config.EnvironName, &environ); err != nil {
    25  		return nil, errors.Trace(err)
    26  	}
    27  
    28  	var apiCaller base.APICaller
    29  	if err := context.Get(config.APICallerName, &apiCaller); err != nil {
    30  		return nil, errors.Trace(err)
    31  	}
    32  	facade := instancepoller.NewAPI(apiCaller)
    33  
    34  	w, err := NewWorker(Config{
    35  		Facade:  facade,
    36  		Environ: environ,
    37  	})
    38  	if err != nil {
    39  		return nil, errors.Trace(err)
    40  	}
    41  	return w, nil
    42  }
    43  
    44  // Manifold returns a Manifold that encapsulates the instancepoller worker.
    45  func Manifold(config ManifoldConfig) dependency.Manifold {
    46  	return dependency.Manifold{
    47  		Inputs: []string{config.APICallerName, config.EnvironName},
    48  		Start:  config.start,
    49  	}
    50  }