support for image pull logs

command/daemon/config.go

@@ -87,6 +87,7 @@ type Config struct {
 
 	Docker struct {
 		Config string `envconfig:"DRONE_DOCKER_CONFIG"`
+		Stream bool   `envconfig:"DRONE_DOCKER_STREAM_PULL" default:"true"`
 	}
 }
 

command/daemon/daemon.go

@@ -78,7 +78,10 @@ func (c *daemonCommand) run(*kingpin.ParseContext) error {
 		),
 	)
 
-	engine, err := engine.NewEnv()
+	opts := engine.Opts{
+		HidePull: !config.Docker.Stream,
+	}
+	engine, err := engine.NewEnv(opts)
 	if err != nil {
 		logrus.WithError(err).
 			Fatalln("cannot load the docker engine")

command/exec.go

@@ -228,7 +228,7 @@ func (c *execCommand) run(*kingpin.ParseContext) error {
 		),
 	)
 
-	engine, err := engine.NewEnv()
+	engine, err := engine.NewEnv(engine.Opts{})
 	if err != nil {
 		return err
 	}

engine/compiler/compiler.go

@@ -266,6 +266,7 @@ func (c *Compiler) Compile(ctx context.Context, args Args) *engine.Spec {
 		step.Envs = environ.Combine(envs, step.Envs)
 		step.WorkingDir = full
 		step.Labels = labels
+		step.Pull = engine.PullIfNotExists
 		step.Volumes = append(step.Volumes, mount)
 		spec.Steps = append(spec.Steps, step)
 

engine/engine_impl.go

@@ -10,6 +10,7 @@ import (
 	"io/ioutil"
 
 	"github.com/drone-runners/drone-runner-docker/internal/docker/image"
+	"github.com/drone-runners/drone-runner-docker/internal/docker/jsonmessage"
 	"github.com/drone-runners/drone-runner-docker/internal/docker/stdcopy"
 	"github.com/drone/runner-go/registry/auths"
 
@@ -18,23 +19,32 @@ import (
 	"docker.io/go-docker/api/types/volume"
 )
 
+// Opts configures the Docker engine.
+type Opts struct {
+	HidePull bool
+}
+
 // Docker implements a Docker pipeline engine.
 type Docker struct {
-	client docker.APIClient
+	client   docker.APIClient
+	hidePull bool
 }
 
 // New returns a new engine.
-func New(client docker.APIClient) *Docker {
+func New(client docker.APIClient, opts Opts) *Docker {
-	return &Docker{client}
+	return &Docker{
+		client:   client,
+		hidePull: opts.HidePull,
+	}
 }
 
 // NewEnv returns a new Engine from the environment.
-func NewEnv() (*Docker, error) {
+func NewEnv(opts Opts) (*Docker, error) {
 	cli, err := docker.NewEnvClient()
 	if err != nil {
 		return nil, err
 	}
-	return New(cli), nil
+	return New(cli, opts), nil
 }
 
 // Ping pings the Docker daemon.
@@ -157,7 +167,11 @@ func (e *Docker) create(ctx context.Context, spec *Spec, step *Step, output io.W
 		(step.Pull == PullDefault && image.IsLatest(step.Image)) {
 		rc, pullerr := e.client.ImagePull(ctx, step.Image, pullopts)
 		if pullerr == nil {
-			io.Copy(ioutil.Discard, rc)
+			if e.hidePull {
+				io.Copy(ioutil.Discard, rc)
+			} else {
+				jsonmessage.Copy(rc, output)
+			}
 			rc.Close()
 		}
 		if pullerr != nil {
@@ -179,7 +193,12 @@ func (e *Docker) create(ctx context.Context, spec *Spec, step *Step, output io.W
 		if pullerr != nil {
 			return pullerr
 		}
-		io.Copy(ioutil.Discard, rc)
+
+		if e.hidePull {
+			io.Copy(ioutil.Discard, rc)
+		} else {
+			jsonmessage.Copy(rc, output)
+		}
 		rc.Close()
 
 		// once the image is successfully pulled we attempt to

internal/docker/jsonmessage/jsonmessage.go

@@ -0,0 +1,61 @@
+// Copyright 2019 Drone.IO Inc. All rights reserved.
+// Use of this source code is governed by the Polyform License
+// that can be found in the LICENSE file.
+
+package jsonmessage
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+)
+
+type jsonError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+func (e *jsonError) Error() string {
+	return e.Message
+}
+
+type jsonMessage struct {
+	ID       string        `json:"id"`
+	Status   string        `json:"status"`
+	Error    *jsonError    `json:"errorDetail"`
+	Progress *jsonProgress `json:"progressDetail"`
+}
+
+type jsonProgress struct {
+}
+
+// Copy copies a json message string to the io.Writer.
+func Copy(in io.Reader, out io.Writer) error {
+	dec := json.NewDecoder(in)
+	for {
+		var jm jsonMessage
+		if err := dec.Decode(&jm); err != nil {
+			if err == io.EOF {
+				break
+			}
+			return err
+		}
+
+		if jm.Error != nil {
+			if jm.Error.Code == 401 {
+				return fmt.Errorf("authentication is required")
+			}
+			return jm.Error
+		}
+
+		if jm.Progress != nil {
+			continue
+		}
+		if jm.ID == "" {
+			fmt.Fprintf(out, "%s\n", jm.Status)
+		} else {
+			fmt.Fprintf(out, "%s: %s\n", jm.ID, jm.Status)
+		}
+	}
+	return nil
+}

internal/docker/jsonmessage/testdata/alpine.json

@@ -0,0 +1,12 @@
+{"status":"Pulling from library/alpine","id":"3.6"}
+{"status":"Pulling fs layer","progressDetail":{},"id":"5a3ea8efae5d"}
+{"status":"Downloading","progressDetail":{"current":21019,"total":2017774},"progress":"[\u003e                                                  ]  21.02kB/2.018MB","id":"5a3ea8efae5d"}
+{"status":"Downloading","progressDetail":{"current":1194721,"total":2017774},"progress":"[=============================\u003e                     ]  1.195MB/2.018MB","id":"5a3ea8efae5d"}
+{"status":"Verifying Checksum","progressDetail":{},"id":"5a3ea8efae5d"}
+{"status":"Download complete","progressDetail":{},"id":"5a3ea8efae5d"}
+{"status":"Extracting","progressDetail":{"current":32768,"total":2017774},"progress":"[\u003e                                                  ]  32.77kB/2.018MB","id":"5a3ea8efae5d"}
+{"status":"Extracting","progressDetail":{"current":786432,"total":2017774},"progress":"[===================\u003e                               ]  786.4kB/2.018MB","id":"5a3ea8efae5d"}
+{"status":"Extracting","progressDetail":{"current":2017774,"total":2017774},"progress":"[==================================================\u003e]  2.018MB/2.018MB","id":"5a3ea8efae5d"}
+{"status":"Pull complete","progressDetail":{},"id":"5a3ea8efae5d"}
+{"status":"Digest: sha256:66790a2b79e1ea3e1dabac43990c54aca5d1ddf268d9a5a0285e4167c8b24475"}
+{"status":"Status: Downloaded newer image for alpine:3.6"}