github.com/makyo/juju@v0.0.0-20160425123129-2608902037e9/cmd/jujud/agent/util/apiagent.go (about)

     1  // Copyright 2016 Canonical Ltd.
     2  // Licensed under the AGPLv3, see LICENCE file for details.
     3  
     4  package util
     5  
     6  import (
     7  	"github.com/juju/juju/agent"
     8  	"github.com/juju/juju/api/base"
     9  	"github.com/juju/juju/worker"
    10  	"github.com/juju/juju/worker/dependency"
    11  )
    12  
    13  // Many manifolds completely depend on an agent and an API connection; this
    14  // type configures them.
    15  type AgentApiManifoldConfig struct {
    16  	AgentName     string
    17  	APICallerName string
    18  }
    19  
    20  // AgentApiStartFunc encapsulates the behaviour that varies among AgentApiManifolds.
    21  type AgentApiStartFunc func(agent.Agent, base.APICaller) (worker.Worker, error)
    22  
    23  // AgentApiManifold returns a dependency.Manifold that calls the supplied start
    24  // func with the API and agent resources defined in the config (once those
    25  // resources are present).
    26  func AgentApiManifold(config AgentApiManifoldConfig, start AgentApiStartFunc) dependency.Manifold {
    27  	return dependency.Manifold{
    28  		Inputs: []string{
    29  			config.AgentName,
    30  			config.APICallerName,
    31  		},
    32  		Start: func(context dependency.Context) (worker.Worker, error) {
    33  			var agent agent.Agent
    34  			if err := context.Get(config.AgentName, &agent); err != nil {
    35  				return nil, err
    36  			}
    37  			var apiCaller base.APICaller
    38  			if err := context.Get(config.APICallerName, &apiCaller); err != nil {
    39  				return nil, err
    40  			}
    41  			return start(agent, apiCaller)
    42  		},
    43  	}
    44  }