Implement secrets concealer in build logs

agent/agent.go

@@ -22,17 +22,18 @@ type Logger interface {
 }
 
 type Agent struct {
-	Update    UpdateFunc
+	Update         UpdateFunc
-	Logger    LoggerFunc
+	Logger         LoggerFunc
-	Engine    build.Engine
+	Engine         build.Engine
-	Timeout   time.Duration
+	Timeout        time.Duration
-	Platform  string
+	Platform       string
-	Namespace string
+	Namespace      string
-	Disable   []string
+	Disable        []string
-	Escalate  []string
+	Escalate       []string
-	Netrc     []string
+	Netrc          []string
-	Local     string
+	Local          string
-	Pull      bool
+	Pull           bool
+	ConcealSecrets bool
 }
 
 func (a *Agent) Poll() error {
@@ -188,6 +189,7 @@ func (a *Agent) exec(spec *yaml.Config, payload *model.Work, cancel <-chan bool)
 		return err
 	}
 
+	secretsReplacer := newSecretsReplacer(payload.Secrets)
 	timeout := time.After(time.Duration(payload.Repo.Timeout) * time.Minute)
 
 	for {
@@ -227,11 +229,25 @@ func (a *Agent) exec(spec *yaml.Config, payload *model.Work, cancel <-chan bool)
 				pipeline.Exec()
 			}
 		case line := <-pipeline.Pipe():
+			// FIXME(vaijab): avoid checking a.ConcealSecrets is true everytime new line is received
+			if a.ConcealSecrets {
+				line.Out = secretsReplacer.Replace(line.Out)
+			}
 			a.Logger(line)
 		}
 	}
 }
 
+// newSecretsReplacer takes []*model.Secret as secrets and returns a list of
+// secret value, "*****" pairs.
+func newSecretsReplacer(secrets []*model.Secret) *strings.Replacer {
+	var r []string
+	for _, s := range secrets {
+		r = append(r, s.Value, "*****")
+	}
+	return strings.NewReplacer(r...)
+}
+
 func toEnv(w *model.Work) map[string]string {
 	envs := map[string]string{
 		"CI":                         "drone",

agent/agent_test.go

@@ -0,0 +1,23 @@
+package agent
+
+import "testing"
+import "github.com/drone/drone/model"
+
+func Test_newSecretsReplacer(t *testing.T) {
+	secrets := []*model.Secret{
+		{Name: "SECRET",
+			Value:  "secret_value",
+			Images: []string{"*"},
+			Events: []string{"*"},
+		},
+	}
+
+	text := "This is SECRET: secret_value"
+	expected := "This is SECRET: *****"
+	secretsReplacer := newSecretsReplacer(secrets)
+	result := secretsReplacer.Replace(text)
+
+	if result != expected {
+		t.Errorf("Wanted %q, got %q.", expected, result)
+	}
+}

drone/agent/agent.go

@@ -75,6 +75,11 @@ var AgentCmd = cli.Command{
 			Name:   "drone-secret",
 			Usage:  "drone agent secret",
 		},
+		cli.BoolFlag{
+			Name:   "conceal-secrets",
+			Usage:  "conceal secrets from build logs",
+			EnvVar: "DRONE_CONCEAL_SECRETS",
+		},
 		cli.DurationFlag{
 			EnvVar: "DRONE_BACKOFF",
 			Name:   "backoff",
@@ -186,12 +191,13 @@ func start(c *cli.Context) {
 			drone:  client,
 			docker: docker,
 			config: config{
-				platform:   c.String("docker-os") + "/" + c.String("docker-arch"),
+				platform:       c.String("docker-os") + "/" + c.String("docker-arch"),
-				timeout:    c.Duration("timeout"),
+				timeout:        c.Duration("timeout"),
-				namespace:  c.String("namespace"),
+				namespace:      c.String("namespace"),
-				privileged: c.StringSlice("privileged"),
+				privileged:     c.StringSlice("privileged"),
-				pull:       c.BoolT("pull"),
+				pull:           c.BoolT("pull"),
-				logs:       int64(c.Int("max-log-size")) * 1000000,
+				logs:           int64(c.Int("max-log-size")) * 1000000,
+				concealSecrets: c.Bool("conceal-secrets"),
 			},
 		}
 

drone/agent/exec.go

@@ -13,12 +13,13 @@ import (
 )
 
 type config struct {
-	platform   string
+	platform       string
-	namespace  string
+	namespace      string
-	privileged []string
+	privileged     []string
-	pull       bool
+	pull           bool
-	logs       int64
+	logs           int64
-	timeout    time.Duration
+	timeout        time.Duration
+	concealSecrets bool
 }
 
 type pipeline struct {
@@ -40,14 +41,15 @@ func (r *pipeline) run(w *model.Work) {
 	engine := docker.NewClient(r.docker)
 
 	a := agent.Agent{
-		Update:    agent.NewClientUpdater(r.drone),
+		Update:         agent.NewClientUpdater(r.drone),
-		Logger:    agent.NewClientLogger(r.drone, w.Job.ID, r.config.logs),
+		Logger:         agent.NewClientLogger(r.drone, w.Job.ID, r.config.logs),
-		Engine:    engine,
+		Engine:         engine,
-		Timeout:   r.config.timeout,
+		Timeout:        r.config.timeout,
-		Platform:  r.config.platform,
+		Platform:       r.config.platform,
-		Namespace: r.config.namespace,
+		Namespace:      r.config.namespace,
-		Escalate:  r.config.privileged,
+		Escalate:       r.config.privileged,
-		Pull:      r.config.pull,
+		Pull:           r.config.pull,
+		ConcealSecrets: r.config.concealSecrets,
 	}
 
 	cancelFunc := func(m *stomp.Message) {

drone/exec.go

@@ -48,6 +48,11 @@ var execCmd = cli.Command{
 			Usage:  "build secrets file in KEY=VALUE format",
 			EnvVar: "DRONE_SECRETS_FILE",
 		},
+		cli.BoolFlag{
+			Name:   "conceal-secrets",
+			Usage:  "conceal secrets from build logs",
+			EnvVar: "DRONE_CONCEAL_SECRETS",
+		},
 		cli.StringSliceFlag{
 			Name:   "matrix",
 			Usage:  "build matrix in KEY=VALUE format",
@@ -326,17 +331,18 @@ func exec(c *cli.Context) error {
 	}
 
 	a := agent.Agent{
-		Update:    agent.NoopUpdateFunc,
+		Update:         agent.NoopUpdateFunc,
-		Logger:    agent.TermLoggerFunc,
+		Logger:         agent.TermLoggerFunc,
-		Engine:    engine,
+		Engine:         engine,
-		Timeout:   c.Duration("timeout.inactivity"),
+		Timeout:        c.Duration("timeout.inactivity"),
-		Platform:  "linux/amd64",
+		Platform:       "linux/amd64",
-		Namespace: c.String("namespace"),
+		Namespace:      c.String("namespace"),
-		Disable:   c.StringSlice("plugin"),
+		Disable:        c.StringSlice("plugin"),
-		Escalate:  c.StringSlice("privileged"),
+		Escalate:       c.StringSlice("privileged"),
-		Netrc:     []string{},
+		Netrc:          []string{},
-		Local:     dir,
+		Local:          dir,
-		Pull:      c.Bool("pull"),
+		Pull:           c.Bool("pull"),
+		ConcealSecrets: c.Bool("conceal-secrets"),
 	}
 
 	payload := &model.Work{