package remoteexec import ( "bytes" "fmt" "io" "io/ioutil" "log" "os" "strings" "time" "github.com/hashicorp/terraform/communicator" "github.com/hashicorp/terraform/communicator/remote" "github.com/hashicorp/terraform/terraform" "github.com/mitchellh/go-linereader" ) // ResourceProvisioner represents a remote exec provisioner type ResourceProvisioner struct{} // Apply executes the remote exec provisioner func (p *ResourceProvisioner) Apply( o terraform.UIOutput, s *terraform.InstanceState, c *terraform.ResourceConfig) error { // Get a new communicator comm, err := communicator.New(s) if err != nil { return err } // Collect the scripts scripts, err := p.collectScripts(c) if err != nil { return err } for _, s := range scripts { defer s.Close() } // Copy and execute each script if err := p.runScripts(o, comm, scripts); err != nil { return err } return nil } // Validate checks if the required arguments are configured func (p *ResourceProvisioner) Validate(c *terraform.ResourceConfig) (ws []string, es []error) { num := 0 for name := range c.Raw { switch name { case "scripts": fallthrough case "script": fallthrough case "inline": num++ default: es = append(es, fmt.Errorf("Unknown configuration '%s'", name)) } } if num != 1 { es = append(es, fmt.Errorf("Must provide one of 'scripts', 'script' or 'inline' to remote-exec")) } return } // generateScript takes the configuration and creates a script to be executed // from the inline configs func (p *ResourceProvisioner) generateScript(c *terraform.ResourceConfig) (string, error) { var lines []string command, ok := c.Config["inline"] if ok { switch cmd := command.(type) { case string: lines = append(lines, cmd) case []string: lines = append(lines, cmd...) case []interface{}: for _, l := range cmd { lStr, ok := l.(string) if ok { lines = append(lines, lStr) } else { return "", fmt.Errorf("Unsupported 'inline' type! Must be string, or list of strings.") } } default: return "", fmt.Errorf("Unsupported 'inline' type! Must be string, or list of strings.") } } lines = append(lines, "") return strings.Join(lines, "\n"), nil } // collectScripts is used to collect all the scripts we need // to execute in preparation for copying them. func (p *ResourceProvisioner) collectScripts(c *terraform.ResourceConfig) ([]io.ReadCloser, error) { // Check if inline _, ok := c.Config["inline"] if ok { script, err := p.generateScript(c) if err != nil { return nil, err } rc := ioutil.NopCloser(bytes.NewReader([]byte(script))) return []io.ReadCloser{rc}, nil } // Collect scripts var scripts []string s, ok := c.Config["script"] if ok { sStr, ok := s.(string) if !ok { return nil, fmt.Errorf("Unsupported 'script' type! Must be a string.") } scripts = append(scripts, sStr) } sl, ok := c.Config["scripts"] if ok { switch slt := sl.(type) { case []string: scripts = append(scripts, slt...) case []interface{}: for _, l := range slt { lStr, ok := l.(string) if ok { scripts = append(scripts, lStr) } else { return nil, fmt.Errorf("Unsupported 'scripts' type! Must be list of strings.") } } default: return nil, fmt.Errorf("Unsupported 'scripts' type! Must be list of strings.") } } // Open all the scripts var fhs []io.ReadCloser for _, s := range scripts { fh, err := os.Open(s) if err != nil { for _, fh := range fhs { fh.Close() } return nil, fmt.Errorf("Failed to open script '%s': %v", s, err) } fhs = append(fhs, fh) } // Done, return the file handles return fhs, nil } // runScripts is used to copy and execute a set of scripts func (p *ResourceProvisioner) runScripts( o terraform.UIOutput, comm communicator.Communicator, scripts []io.ReadCloser) error { // Wait and retry until we establish the connection err := retryFunc(comm.Timeout(), func() error { err := comm.Connect(o) return err }) if err != nil { return err } defer comm.Disconnect() for _, script := range scripts { var cmd *remote.Cmd outR, outW := io.Pipe() errR, errW := io.Pipe() outDoneCh := make(chan struct{}) errDoneCh := make(chan struct{}) go p.copyOutput(o, outR, outDoneCh) go p.copyOutput(o, errR, errDoneCh) err = retryFunc(comm.Timeout(), func() error { remotePath := comm.ScriptPath() if err := comm.UploadScript(remotePath, script); err != nil { return fmt.Errorf("Failed to upload script: %v", err) } cmd = &remote.Cmd{ Command: remotePath, Stdout: outW, Stderr: errW, } if err := comm.Start(cmd); err != nil { return fmt.Errorf("Error starting script: %v", err) } return nil }) if err == nil { cmd.Wait() if cmd.ExitStatus != 0 { err = fmt.Errorf("Script exited with non-zero exit status: %d", cmd.ExitStatus) } } // Wait for output to clean up outW.Close() errW.Close() <-outDoneCh <-errDoneCh // If we have an error, return it out now that we've cleaned up if err != nil { return err } } return nil } func (p *ResourceProvisioner) copyOutput( o terraform.UIOutput, r io.Reader, doneCh chan<- struct{}) { defer close(doneCh) lr := linereader.New(r) for line := range lr.Ch { o.Output(line) } } // retryFunc is used to retry a function for a given duration func retryFunc(timeout time.Duration, f func() error) error { finish := time.After(timeout) for { err := f() if err == nil { return nil } log.Printf("Retryable error: %v", err) select { case <-finish: return err case <-time.After(3 * time.Second): } } }