/
providerregistry.go
100 lines (87 loc) · 2.77 KB
/
providerregistry.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
// Copyright 2015 Canonical Ltd.
// Licensed under the AGPLv3, see LICENCE file for details.
package registry
import (
"github.com/juju/errors"
"github.com/juju/juju/storage"
"github.com/juju/juju/storage/provider"
)
//
// A registry of storage providers.
//
// providers maps from provider type to storage.Provider for
// each registered provider type.
var providers = make(map[storage.ProviderType]storage.Provider)
// RegisterProvider registers a new storage provider of the given type.
//
// If the provider is nil, then any previously registered provider with
// the same type will be unregistered; this is purely available for
// testing.
func RegisterProvider(providerType storage.ProviderType, p storage.Provider) {
if p == nil {
delete(providers, providerType)
return
}
if providers[providerType] != nil {
panic(errors.Errorf("juju: duplicate storage provider type %q", providerType))
}
providers[providerType] = p
}
// StorageProvider returns the previously registered provider with the given type.
func StorageProvider(providerType storage.ProviderType) (storage.Provider, error) {
p, ok := providers[providerType]
if !ok {
return nil, errors.NotFoundf("storage provider %q", providerType)
}
return p, nil
}
//
// A registry of storage provider types which are
// valid for a Juju Environ.
//
// supportedEnvironProviders maps from environment type to a slice of
// supported ProviderType(s).
var supportedEnvironProviders = make(map[string][]storage.ProviderType)
// RegisterEnvironStorageProviders records which storage provider types
// are valid for an environment.
// This is to be called from the environ provider's init().
// Also registered will be provider types common to all environments.
func RegisterEnvironStorageProviders(envType string, providers ...storage.ProviderType) {
existing := supportedEnvironProviders[envType]
for _, p := range providers {
if IsProviderSupported(envType, p) {
continue
}
existing = append(existing, p)
}
// Add the common providers.
for p := range provider.CommonProviders() {
if IsProviderSupported(envType, p) {
continue
}
existing = append(existing, p)
}
supportedEnvironProviders[envType] = existing
}
// Returns true is provider is supported for the environment.
func IsProviderSupported(envType string, providerType storage.ProviderType) bool {
providerTypes, ok := EnvironStorageProviders(envType)
if !ok {
return false
}
for _, p := range providerTypes {
if p == providerType {
return true
}
}
return false
}
// EnvironStorageProviders returns storage provider types
// for the specified environment.
func EnvironStorageProviders(envType string) ([]storage.ProviderType, bool) {
providerTypes, ok := supportedEnvironProviders[envType]
if !ok {
return nil, false
}
return providerTypes, true
}