terraform/backend/remote-state/swift/backend_state.go

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package swift
import (
"fmt"
"strings"
"github.com/hashicorp/terraform/backend"
"github.com/hashicorp/terraform/states"
"github.com/hashicorp/terraform/states/remote"
"github.com/hashicorp/terraform/states/statemgr"
)
const (
objectEnvPrefix = "env-"
delimiter = "/"
)
func (b *Backend) Workspaces() ([]string, error) {
client := &RemoteClient{
client: b.client,
container: b.container,
archive: b.archive,
archiveContainer: b.archiveContainer,
expireSecs: b.expireSecs,
lockState: b.lock,
}
// List our container objects
objectNames, err := client.ListObjectsNames(objectEnvPrefix, delimiter)
if err != nil {
return nil, err
}
// Find the envs, we use a map since we can get duplicates with
// path suffixes.
envs := map[string]struct{}{}
for _, object := range objectNames {
object = strings.TrimPrefix(object, objectEnvPrefix)
object = strings.TrimSuffix(object, delimiter)
// Ignore objects that still contain a "/"
// as we dont store states in subdirectories
if idx := strings.Index(object, delimiter); idx >= 0 {
continue
}
// swift is eventually consistent, thus a deleted object may
// be listed in objectList. To ensure consistency, we query
// each object with a "newest" arg set to true
payload, err := client.get(b.objectName(object))
if err != nil {
return nil, err
}
if payload == nil {
// object doesn't exist anymore. skipping.
continue
}
envs[object] = struct{}{}
}
result := make([]string, 1, len(envs)+1)
result[0] = backend.DefaultStateName
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for k := range envs {
result = append(result, k)
}
return result, nil
}
func (b *Backend) DeleteWorkspace(name string) error {
if name == backend.DefaultStateName || name == "" {
return fmt.Errorf("can't delete default state")
}
client := &RemoteClient{
client: b.client,
container: b.container,
archive: b.archive,
archiveContainer: b.archiveContainer,
expireSecs: b.expireSecs,
objectName: b.objectName(name),
lockState: b.lock,
}
// Delete our object
err := client.Delete()
return err
}
func (b *Backend) StateMgr(name string) (statemgr.Full, error) {
if name == "" {
return nil, fmt.Errorf("missing state name")
}
client := &RemoteClient{
client: b.client,
container: b.container,
archive: b.archive,
archiveContainer: b.archiveContainer,
expireSecs: b.expireSecs,
objectName: b.objectName(name),
lockState: b.lock,
}
var stateMgr statemgr.Full = &remote.State{Client: client}
// If we're not locking, disable it
if !b.lock {
stateMgr = &statemgr.LockDisabled{Inner: stateMgr}
}
// Check to see if this state already exists.
// If we're trying to force-unlock a state, we can't take the lock before
// fetching the state. If the state doesn't exist, we have to assume this
// is a normal create operation, and take the lock at that point.
//
// If we need to force-unlock, but for some reason the state no longer
// exists, the user will have to use openstack tools to manually fix the
// situation.
existing, err := b.Workspaces()
if err != nil {
return nil, err
}
exists := false
for _, s := range existing {
if s == name {
exists = true
break
}
}
// We need to create the object so it's listed by States.
if !exists {
// the default state always exists
if name == backend.DefaultStateName {
return stateMgr, nil
}
// Grab a lock, we use this to write an empty state if one doesn't
// exist already. We have to write an empty state as a sentinel value
// so States() knows it exists.
lockInfo := statemgr.NewLockInfo()
lockInfo.Operation = "init"
lockId, err := stateMgr.Lock(lockInfo)
if err != nil {
return nil, fmt.Errorf("failed to lock state in Swift: %s", err)
}
// Local helper function so we can call it multiple places
lockUnlock := func(parent error) error {
if err := stateMgr.Unlock(lockId); err != nil {
return fmt.Errorf(strings.TrimSpace(errStateUnlock), lockId, err)
}
return parent
}
// Grab the value
if err := stateMgr.RefreshState(); err != nil {
err = lockUnlock(err)
return nil, err
}
// If we have no state, we have to create an empty state
if v := stateMgr.State(); v == nil {
if err := stateMgr.WriteState(states.NewState()); err != nil {
err = lockUnlock(err)
return nil, err
}
if err := stateMgr.PersistState(); err != nil {
err = lockUnlock(err)
return nil, err
}
}
// Unlock, the state should now be initialized
if err := lockUnlock(nil); err != nil {
return nil, err
}
}
return stateMgr, nil
}
func (b *Backend) objectName(name string) string {
if name != backend.DefaultStateName {
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name = fmt.Sprintf("%s%s/%s", objectEnvPrefix, name, b.stateName)
} else {
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name = b.stateName
}
return name
}
const errStateUnlock = `
Error unlocking Swift state. Lock ID: %s
Error: %s
You may have to force-unlock this state in order to use it again.
The Swift backend acquires a lock during initialization to ensure
the minimum required keys are prepared.
`