forked from hashicorp/terraform
-
Notifications
You must be signed in to change notification settings - Fork 7
/
backend.go
169 lines (145 loc) · 6.66 KB
/
backend.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
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
// Package backend provides interfaces that the CLI uses to interact with
// Terraform. A backend provides the abstraction that allows the same CLI
// to simultaneously support both local and remote operations for seamlessly
// using Terraform in a team environment.
package backend
import (
"context"
"errors"
"time"
"github.com/hashicorp/terraform/config/module"
"github.com/hashicorp/terraform/state"
"github.com/hashicorp/terraform/terraform"
)
// This is the name of the default, initial state that every backend
// must have. This state cannot be deleted.
const DefaultStateName = "default"
// Error value to return when a named state operation isn't supported.
// This must be returned rather than a custom error so that the Terraform
// CLI can detect it and handle it appropriately.
var ErrNamedStatesNotSupported = errors.New("named states not supported")
// Backend is the minimal interface that must be implemented to enable Terraform.
type Backend interface {
// Ask for input and configure the backend. Similar to
// terraform.ResourceProvider.
Input(terraform.UIInput, *terraform.ResourceConfig) (*terraform.ResourceConfig, error)
Validate(*terraform.ResourceConfig) ([]string, []error)
Configure(*terraform.ResourceConfig) error
// State returns the current state for this environment. This state may
// not be loaded locally: the proper APIs should be called on state.State
// to load the state. If the state.State is a state.Locker, it's up to the
// caller to call Lock and Unlock as needed.
//
// If the named state doesn't exist it will be created. The "default" state
// is always assumed to exist.
State(name string) (state.State, error)
// DeleteState removes the named state if it exists. It is an error
// to delete the default state.
//
// DeleteState does not prevent deleting a state that is in use. It is the
// responsibility of the caller to hold a Lock on the state when calling
// this method.
DeleteState(name string) error
// States returns a list of configured named states.
States() ([]string, error)
}
// Enhanced implements additional behavior on top of a normal backend.
//
// Enhanced backends allow customizing the behavior of Terraform operations.
// This allows Terraform to potentially run operations remotely, load
// configurations from external sources, etc.
type Enhanced interface {
Backend
// Operation performs a Terraform operation such as refresh, plan, apply.
// It is up to the implementation to determine what "performing" means.
// This DOES NOT BLOCK. The context returned as part of RunningOperation
// should be used to block for completion.
// If the state used in the operation can be locked, it is the
// responsibility of the Backend to lock the state for the duration of the
// running operation.
Operation(context.Context, *Operation) (*RunningOperation, error)
}
// Local implements additional behavior on a Backend that allows local
// operations in addition to remote operations.
//
// This enables more behaviors of Terraform that require more data such
// as `console`, `import`, `graph`. These require direct access to
// configurations, variables, and more. Not all backends may support this
// so we separate it out into its own optional interface.
type Local interface {
// Context returns a runnable terraform Context. The operation parameter
// doesn't need a Type set but it needs other options set such as Module.
Context(*Operation) (*terraform.Context, state.State, error)
}
// An operation represents an operation for Terraform to execute.
//
// Note that not all fields are supported by all backends and can result
// in an error if set. All backend implementations should show user-friendly
// errors explaining any incorrectly set values. For example, the local
// backend doesn't support a PlanId being set.
//
// The operation options are purposely designed to have maximal compatibility
// between Terraform and Terraform Servers (a commercial product offered by
// HashiCorp). Therefore, it isn't expected that other implementation support
// every possible option. The struct here is generalized in order to allow
// even partial implementations to exist in the open, without walling off
// remote functionality 100% behind a commercial wall. Anyone can implement
// against this interface and have Terraform interact with it just as it
// would with HashiCorp-provided Terraform Servers.
type Operation struct {
// Type is the operation to perform.
Type OperationType
// PlanId is an opaque value that backends can use to execute a specific
// plan for an apply operation.
//
// PlanOutBackend is the backend to store with the plan. This is the
// backend that will be used when applying the plan.
PlanId string
PlanRefresh bool // PlanRefresh will do a refresh before a plan
PlanOutPath string // PlanOutPath is the path to save the plan
PlanOutBackend *terraform.BackendState
// Module settings specify the root module to use for operations.
Module *module.Tree
// Plan is a plan that was passed as an argument. This is valid for
// plan and apply arguments but may not work for all backends.
Plan *terraform.Plan
// The options below are more self-explanatory and affect the runtime
// behavior of the operation.
Destroy bool
Targets []string
Variables map[string]interface{}
AutoApprove bool
DestroyForce bool
// Input/output/control options.
UIIn terraform.UIInput
UIOut terraform.UIOutput
// If LockState is true, the Operation must Lock any
// state.Lockers for its duration, and Unlock when complete.
LockState bool
// The duration to retry obtaining a State lock.
StateLockTimeout time.Duration
// Workspace is the name of the workspace that this operation should run
// in, which controls which named state is used.
Workspace string
}
// RunningOperation is the result of starting an operation.
type RunningOperation struct {
// Context should be used to track Done and Err for errors.
//
// For implementers of a backend, this context should not wrap the
// passed in context. Otherwise, canceling the parent context will
// immediately mark this context as "done" but those aren't the semantics
// we want: we want this context to be done only when the operation itself
// is fully done.
context.Context
// Err is the error of the operation. This is populated after
// the operation has completed.
Err error
// PlanEmpty is populated after a Plan operation completes without error
// to note whether a plan is empty or has changes.
PlanEmpty bool
// State is the final state after the operation completed. Persisting
// this state is managed by the backend. This should only be read
// after the operation completes to avoid read/write races.
State *terraform.State
}