forked from juju/juju
/
manifold.go
101 lines (93 loc) · 2.68 KB
/
manifold.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
// Copyright 2016 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package migrationminion
import (
"github.com/juju/errors"
"github.com/juju/juju/agent"
"github.com/juju/juju/api"
"github.com/juju/juju/api/base"
"github.com/juju/juju/worker"
"github.com/juju/juju/worker/dependency"
"github.com/juju/juju/worker/fortress"
)
// ManifoldConfig defines the names of the manifolds on which a
// Worker manifold will depend.
type ManifoldConfig struct {
AgentName string
APICallerName string
FortressName string
APIOpen func(*api.Info, api.DialOpts) (api.Connection, error)
ValidateMigration func(base.APICaller) error
NewFacade func(base.APICaller) (Facade, error)
NewWorker func(Config) (worker.Worker, error)
}
// validate is called by start to check for bad configuration.
func (config ManifoldConfig) validate() error {
if config.AgentName == "" {
return errors.NotValidf("empty AgentName")
}
if config.APICallerName == "" {
return errors.NotValidf("empty APICallerName")
}
if config.FortressName == "" {
return errors.NotValidf("empty FortressName")
}
if config.APIOpen == nil {
return errors.NotValidf("nil APIOpen")
}
if config.ValidateMigration == nil {
return errors.NotValidf("nil ValidateMigration")
}
if config.NewFacade == nil {
return errors.NotValidf("nil NewFacade")
}
if config.NewWorker == nil {
return errors.NotValidf("nil NewWorker")
}
return nil
}
// start is a StartFunc for a Worker manifold.
func (config ManifoldConfig) start(context dependency.Context) (worker.Worker, error) {
if err := config.validate(); err != nil {
return nil, errors.Trace(err)
}
var agent agent.Agent
if err := context.Get(config.AgentName, &agent); err != nil {
return nil, errors.Trace(err)
}
var apiCaller base.APICaller
if err := context.Get(config.APICallerName, &apiCaller); err != nil {
return nil, errors.Trace(err)
}
var guard fortress.Guard
if err := context.Get(config.FortressName, &guard); err != nil {
return nil, errors.Trace(err)
}
facade, err := config.NewFacade(apiCaller)
if err != nil {
return nil, errors.Trace(err)
}
worker, err := config.NewWorker(Config{
Agent: agent,
Facade: facade,
Guard: guard,
APIOpen: config.APIOpen,
ValidateMigration: config.ValidateMigration,
})
if err != nil {
return nil, errors.Trace(err)
}
return worker, nil
}
// Manifold returns a dependency manifold that runs the migration
// worker.
func Manifold(config ManifoldConfig) dependency.Manifold {
return dependency.Manifold{
Inputs: []string{
config.AgentName,
config.APICallerName,
config.FortressName,
},
Start: config.start,
}
}