package azure import ( "bytes" "encoding/base64" "encoding/json" "fmt" "io" "log" "github.com/Azure/azure-sdk-for-go/storage" multierror "github.com/hashicorp/go-multierror" uuid "github.com/hashicorp/go-uuid" "github.com/hashicorp/terraform/state" "github.com/hashicorp/terraform/state/remote" "github.com/hashicorp/terraform/states" ) const ( leaseHeader = "x-ms-lease-id" // Must be lower case lockInfoMetaKey = "terraformlockid" ) type RemoteClient struct { blobClient storage.BlobStorageClient containerName string keyName string leaseID string } func (c *RemoteClient) Get() (*remote.Payload, error) { containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) options := &storage.GetBlobOptions{} if c.leaseID != "" { options.LeaseID = c.leaseID } blob, err := blobReference.Get(options) if err != nil { if storErr, ok := err.(storage.AzureStorageServiceError); ok { if storErr.Code == "BlobNotFound" { return nil, nil } } return nil, err } defer blob.Close() buf := bytes.NewBuffer(nil) if _, err := io.Copy(buf, blob); err != nil { return nil, fmt.Errorf("Failed to read remote state: %s", err) } payload := &remote.Payload{ Data: buf.Bytes(), } // If there was no data, then return nil if len(payload.Data) == 0 { return nil, nil } return payload, nil } func (c *RemoteClient) Put(data []byte) error { getOptions := &storage.GetBlobMetadataOptions{} setOptions := &storage.SetBlobPropertiesOptions{} putOptions := &storage.PutBlobOptions{} containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) blobReference.Properties.ContentType = "application/json" blobReference.Properties.ContentLength = int64(len(data)) if c.leaseID != "" { getOptions.LeaseID = c.leaseID setOptions.LeaseID = c.leaseID putOptions.LeaseID = c.leaseID } exists, err := blobReference.Exists() if err != nil { return err } if exists { err = blobReference.GetMetadata(getOptions) if err != nil { return err } } reader := bytes.NewReader(data) err = blobReference.CreateBlockBlobFromReader(reader, putOptions) if err != nil { return err } return blobReference.SetProperties(setOptions) } func (c *RemoteClient) Delete() error { containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) options := &storage.DeleteBlobOptions{} if c.leaseID != "" { options.LeaseID = c.leaseID } return blobReference.Delete(options) } func (c *RemoteClient) Lock(info *state.LockInfo) (string, error) { stateName := fmt.Sprintf("%s/%s", c.containerName, c.keyName) info.Path = stateName if info.ID == "" { lockID, err := uuid.GenerateUUID() if err != nil { return "", err } info.ID = lockID } getLockInfoErr := func(err error) error { lockInfo, infoErr := c.getLockInfo() if infoErr != nil { err = multierror.Append(err, infoErr) } return &state.LockError{ Err: err, Info: lockInfo, } } containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) leaseID, err := blobReference.AcquireLease(-1, info.ID, &storage.LeaseOptions{}) if err != nil { if storErr, ok := err.(storage.AzureStorageServiceError); ok && storErr.Code != "BlobNotFound" { return "", getLockInfoErr(err) } // failed to lock as there was no state blob, write empty state stateMgr := &remote.State{Client: c} // ensure state is actually empty if err := stateMgr.RefreshState(); err != nil { return "", fmt.Errorf("Failed to refresh state before writing empty state for locking: %s", err) } log.Print("[DEBUG] Could not lock as state blob did not exist, creating with empty state") if v := stateMgr.State(); v == nil { if err := stateMgr.WriteState(states.NewState()); err != nil { return "", fmt.Errorf("Failed to write empty state for locking: %s", err) } if err := stateMgr.PersistState(); err != nil { return "", fmt.Errorf("Failed to persist empty state for locking: %s", err) } } leaseID, err = blobReference.AcquireLease(-1, info.ID, &storage.LeaseOptions{}) if err != nil { return "", getLockInfoErr(err) } } info.ID = leaseID c.leaseID = leaseID if err := c.writeLockInfo(info); err != nil { return "", err } return info.ID, nil } func (c *RemoteClient) getLockInfo() (*state.LockInfo, error) { containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) err := blobReference.GetMetadata(&storage.GetBlobMetadataOptions{}) if err != nil { return nil, err } raw := blobReference.Metadata[lockInfoMetaKey] if raw == "" { return nil, fmt.Errorf("blob metadata %q was empty", lockInfoMetaKey) } data, err := base64.StdEncoding.DecodeString(raw) if err != nil { return nil, err } lockInfo := &state.LockInfo{} err = json.Unmarshal(data, lockInfo) if err != nil { return nil, err } return lockInfo, nil } // writes info to blob meta data, deletes metadata entry if info is nil func (c *RemoteClient) writeLockInfo(info *state.LockInfo) error { containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) err := blobReference.GetMetadata(&storage.GetBlobMetadataOptions{ LeaseID: c.leaseID, }) if err != nil { return err } if info == nil { delete(blobReference.Metadata, lockInfoMetaKey) } else { value := base64.StdEncoding.EncodeToString(info.Marshal()) blobReference.Metadata[lockInfoMetaKey] = value } opts := &storage.SetBlobMetadataOptions{ LeaseID: c.leaseID, } return blobReference.SetMetadata(opts) } func (c *RemoteClient) Unlock(id string) error { lockErr := &state.LockError{} lockInfo, err := c.getLockInfo() if err != nil { lockErr.Err = fmt.Errorf("failed to retrieve lock info: %s", err) return lockErr } lockErr.Info = lockInfo if lockInfo.ID != id { lockErr.Err = fmt.Errorf("lock id %q does not match existing lock", id) return lockErr } if err := c.writeLockInfo(nil); err != nil { lockErr.Err = fmt.Errorf("failed to delete lock info from metadata: %s", err) return lockErr } containerReference := c.blobClient.GetContainerReference(c.containerName) blobReference := containerReference.GetBlobReference(c.keyName) err = blobReference.ReleaseLease(id, &storage.LeaseOptions{}) if err != nil { lockErr.Err = err return lockErr } c.leaseID = "" return nil }