source tmate binary from docker image

engine/compiler/compiler.go

@@ -53,6 +53,12 @@ type Resources struct {
 	ShmSize    int64
 }
 
+// Tmate defines tmate settings.
+type Tmate struct {
+	Image   string
+	Enabled bool
+}
+
 // Compiler compiles the Yaml configuration file to an
 // intermediate representation optimized for simple execution.
 type Compiler struct {
@@ -92,6 +98,10 @@ type Compiler struct {
 	// applies to pipeline containers.
 	Resources Resources
 
+	// Tate provides global configration options for tmate
+	// live debugging.
+	Tmate Tmate
+
 	// Secret returns a named secret value that can be injected
 	// into the pipeline step.
 	Secret secret.Provider
@@ -307,6 +317,38 @@ func (c *Compiler) Compile(ctx context.Context, args runtime.CompilerArgs) runti
 		}
 	}
 
+	// create internal steps if build running in debug mode
+	if c.Tmate.Enabled && args.Build.Debug && pipeline.Platform.OS != "windows" {
+		// first we need to add an internal setup step to the pipeline
+		// to copy over the tmate binary. Internal steps are not visible
+		// to the end user.
+		spec.Internal = append(spec.Internal, &engine.Step{
+			ID:         random(),
+			Labels:     labels,
+			Pull:       engine.PullIfNotExists,
+			Image:      image.Expand(c.Tmate.Image),
+			Entrypoint: []string{"/bin/sh", "-c"},
+			Command:    []string{"cp /bin/tmate /usr/drone/bin/"},
+			Network:    "none",
+		})
+
+		// next we create a temporary volume to share the tmate binary
+		// with the pipeline containers.
+		for _, step := range append(spec.Steps, spec.Internal...) {
+			step.Volumes = append(step.Volumes, &engine.VolumeMount{
+				Name: "_addons",
+				Path: "/usr/drone/bin",
+			})
+		}
+		spec.Volumes = append(spec.Volumes, &engine.Volume{
+			EmptyDir: &engine.VolumeEmptyDir{
+				ID:     random(),
+				Name:   "_addons",
+				Labels: labels,
+			},
+		})
+	}
+
 	if isGraph(spec) == false {
 		configureSerial(spec)
 	} else if pipeline.Clone.Disable == false {
@@ -345,7 +387,7 @@ func (c *Compiler) Compile(ctx context.Context, args runtime.CompilerArgs) runti
 		}
 	}
 
-	for _, step := range spec.Steps {
+	for _, step := range append(spec.Steps, spec.Internal...) {
 	STEPS:
 		for _, cred := range creds {
 			if image.MatchHostname(step.Image, cred.Address) {

engine/compiler/shell/shell.go

@@ -58,23 +58,8 @@ echo + %s
 
 const tmateScript = `
 remote_debug() {
-	if [ "$?" -ne "0" ];
-	then
-
-		if command -v apt-get &> /dev/null
-		then
-			apt-get update -qq
-			apt-get install xz-utils --assume-yes -qq
-		fi
-
-		wget https://github.com/tmate-io/tmate/releases/download/2.4.0/tmate-2.4.0-static-linux-amd64.tar.xz
-		tar -xf tmate-2.4.0-static-linux-amd64.tar.xz
-		mv tmate-2.4.0-static-linux-amd64/tmate /usr/bin/
-		chmod +x /usr/bin/tmate
-		rm -rf tmate-2.4.0-static-linux-amd64
-		rm -rf tmate-2.4.0-static-linux-amd64.tar.xz
-		tmate -F
-
+	if [ "$?" -ne "0" ]; then
+		/usr/drone/bin/tmate -F
 	fi
 }
 

engine/engine.go

@@ -8,6 +8,7 @@ import (
 	"context"
 	"io"
 	"io/ioutil"
+	"time"
 
 	"github.com/drone-runners/drone-runner-docker/internal/docker/errors"
 	"github.com/drone-runners/drone-runner-docker/internal/docker/image"
@@ -90,6 +91,35 @@ func (e *Docker) Setup(ctx context.Context, specv runtime.Spec) error {
 		Labels:  spec.Network.Labels,
 	})
 
+	// launches the inernal setup steps
+	for _, step := range spec.Internal {
+		if err := e.create(ctx, spec, step, ioutil.Discard); err != nil {
+			logger.FromContext(ctx).
+				WithError(err).
+				WithField("container", step.ID).
+				Errorln("cannot create tmate container")
+			return err
+		}
+		if err := e.start(ctx, step.ID); err != nil {
+			logger.FromContext(ctx).
+				WithError(err).
+				WithField("container", step.ID).
+				Errorln("cannot start tmate container")
+			return err
+		}
+		if !step.Detach {
+			// the internal containers perform short-lived tasks
+			// and should not require > 1 minute to execute.
+			//
+			// just to be on the safe side we apply a timeout to
+			// ensure we never block pipeline execution because we
+			// are waiting on an internal task.
+			ctx, cancel := context.WithTimeout(ctx, time.Minute)
+			defer cancel()
+			e.wait(ctx, step.ID)
+		}
+	}
+
 	return errors.TrimExtraInfo(err)
 }
 
@@ -104,12 +134,12 @@ func (e *Docker) Destroy(ctx context.Context, specv runtime.Spec) error {
 	}
 
 	// stop all containers
-	for _, step := range spec.Steps {
+	for _, step := range append(spec.Steps, spec.Internal...) {
 		e.client.ContainerKill(ctx, step.ID, "9")
 	}
 
 	// cleanup all containers
-	for _, step := range spec.Steps {
+	for _, step := range append(spec.Steps, spec.Internal...) {
 		e.client.ContainerRemove(ctx, step.ID, removeOpts)
 	}
 

engine/spec.go

@@ -17,6 +17,7 @@ type (
 	Spec struct {
 		Platform Platform  `json:"platform,omitempty"`
 		Steps    []*Step   `json:"steps,omitempty"`
+		Internal []*Step   `json:"internal,omitempty"`
 		Volumes  []*Volume `json:"volumes,omitempty"`
 		Network  Network   `json:"network"`
 	}