package gcs import ( "encoding/json" "fmt" "io/ioutil" "strconv" "cloud.google.com/go/storage" multierror "github.com/hashicorp/go-multierror" "github.com/hashicorp/terraform/states/remote" "github.com/hashicorp/terraform/states/statemgr" "golang.org/x/net/context" ) // remoteClient is used by "state/remote".State to read and write // blobs representing state. // Implements "state/remote".ClientLocker type remoteClient struct { storageContext context.Context storageClient *storage.Client bucketName string stateFilePath string lockFilePath string encryptionKey []byte } func (c *remoteClient) Get() (payload *remote.Payload, err error) { stateFileReader, err := c.stateFile().NewReader(c.storageContext) if err != nil { if err == storage.ErrObjectNotExist { return nil, nil } else { return nil, fmt.Errorf("Failed to open state file at %v: %v", c.stateFileURL(), err) } } defer stateFileReader.Close() stateFileContents, err := ioutil.ReadAll(stateFileReader) if err != nil { return nil, fmt.Errorf("Failed to read state file from %v: %v", c.stateFileURL(), err) } stateFileAttrs, err := c.stateFile().Attrs(c.storageContext) if err != nil { return nil, fmt.Errorf("Failed to read state file attrs from %v: %v", c.stateFileURL(), err) } result := &remote.Payload{ Data: stateFileContents, MD5: stateFileAttrs.MD5, } return result, nil } func (c *remoteClient) Put(data []byte) error { err := func() error { stateFileWriter := c.stateFile().NewWriter(c.storageContext) if _, err := stateFileWriter.Write(data); err != nil { return err } return stateFileWriter.Close() }() if err != nil { return fmt.Errorf("Failed to upload state to %v: %v", c.stateFileURL(), err) } return nil } func (c *remoteClient) Delete() error { if err := c.stateFile().Delete(c.storageContext); err != nil { return fmt.Errorf("Failed to delete state file %v: %v", c.stateFileURL(), err) } return nil } // Lock writes to a lock file, ensuring file creation. Returns the generation // number, which must be passed to Unlock(). func (c *remoteClient) Lock(info *statemgr.LockInfo) (string, error) { // update the path we're using // we can't set the ID until the info is written info.Path = c.lockFileURL() infoJson, err := json.Marshal(info) if err != nil { return "", err } lockFile := c.lockFile() w := lockFile.If(storage.Conditions{DoesNotExist: true}).NewWriter(c.storageContext) err = func() error { if _, err := w.Write(infoJson); err != nil { return err } return w.Close() }() if err != nil { return "", c.lockError(fmt.Errorf("writing %q failed: %v", c.lockFileURL(), err)) } info.ID = strconv.FormatInt(w.Attrs().Generation, 10) return info.ID, nil } func (c *remoteClient) Unlock(id string) error { gen, err := strconv.ParseInt(id, 10, 64) if err != nil { return fmt.Errorf("Lock ID should be numerical value, got '%s'", id) } if err := c.lockFile().If(storage.Conditions{GenerationMatch: gen}).Delete(c.storageContext); err != nil { return c.lockError(err) } return nil } func (c *remoteClient) lockError(err error) *statemgr.LockError { lockErr := &statemgr.LockError{ Err: err, } info, infoErr := c.lockInfo() if infoErr != nil { lockErr.Err = multierror.Append(lockErr.Err, infoErr) } else { lockErr.Info = info } return lockErr } // lockInfo reads the lock file, parses its contents and returns the parsed // LockInfo struct. func (c *remoteClient) lockInfo() (*statemgr.LockInfo, error) { r, err := c.lockFile().NewReader(c.storageContext) if err != nil { return nil, err } defer r.Close() rawData, err := ioutil.ReadAll(r) if err != nil { return nil, err } info := &statemgr.LockInfo{} if err := json.Unmarshal(rawData, info); err != nil { return nil, err } // We use the Generation as the ID, so overwrite the ID in the json. // This can't be written into the Info, since the generation isn't known // until it's written. attrs, err := c.lockFile().Attrs(c.storageContext) if err != nil { return nil, err } info.ID = strconv.FormatInt(attrs.Generation, 10) return info, nil } func (c *remoteClient) stateFile() *storage.ObjectHandle { h := c.storageClient.Bucket(c.bucketName).Object(c.stateFilePath) if len(c.encryptionKey) > 0 { return h.Key(c.encryptionKey) } return h } func (c *remoteClient) stateFileURL() string { return fmt.Sprintf("gs://%v/%v", c.bucketName, c.stateFilePath) } func (c *remoteClient) lockFile() *storage.ObjectHandle { return c.storageClient.Bucket(c.bucketName).Object(c.lockFilePath) } func (c *remoteClient) lockFileURL() string { return fmt.Sprintf("gs://%v/%v", c.bucketName, c.lockFilePath) }