Use random string as temporary tag

card.go

@@ -17,8 +17,8 @@ import (
 	"github.com/inhies/go-bytesize"
 )
 
-func (p Plugin) writeCard(buildName string) error {
+func (p Plugin) writeCard() error {
-	cmd := exec.Command(dockerExe, "inspect", buildName)
+	cmd := exec.Command(dockerExe, "inspect", p.Build.TempTag)
 	data, err := cmd.CombinedOutput()
 	if err != nil {
 		return err

cmd/drone-docker/main.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"math/rand"
 	"os"
 	"runtime"
+	"time"
 
 	"github.com/joho/godotenv"
 	"github.com/sirupsen/logrus"
@@ -14,6 +16,7 @@ import (
 
 var (
 	version = "unknown"
+	charset = []byte("abcdefghijklmnopqrstuvwxyz")
 )
 
 func main() {
@@ -318,6 +321,7 @@ func run(c *cli.Context) error {
 		Build: docker.Build{
 			Remote:      c.String("remote.url"),
 			Name:        c.String("commit.sha"),
+			TempTag:     generateTempTag(),
 			Dockerfile:  c.String("dockerfile"),
 			Context:     c.String("context"),
 			Tags:        c.StringSlice("tags"),
@@ -383,6 +387,20 @@ func run(c *cli.Context) error {
 	return plugin.Exec()
 }
 
+func generateTempTag() string {
+	tagLength := 8
+	return randomString(tagLength)
+}
+
+func randomString(n int) string {
+	rand.Seed(time.Now().UTC().UnixNano())
+	b := make([]byte, n)
+	for i := range b {
+		b[i] = charset[rand.Intn(len(charset))]
+	}
+	return string(b)
+}
+
 func GetExecCmd() string {
 	if runtime.GOOS == "windows" {
 		return "C:/bin/drone-docker.exe"

docker.go

@@ -45,6 +45,7 @@ type (
 	Build struct {
 		Remote      string   // Git remote URL
 		Name        string   // Docker build using default named tag
+		TempTag     string   // Temporary tag used during docker build
 		Dockerfile  string   // Docker build Dockerfile
 		Context     string   // Docker build context
 		Tags        []string // Docker build tags
@@ -195,11 +196,10 @@ func (p Plugin) Exec() error {
 		}
 	}
 
-	buildName := getUniqueBuildName(p.Build.Repo, p.Build.Name)
+	cmds = append(cmds, commandBuild(p.Build)) // docker build
-	cmds = append(cmds, commandBuild(p.Build, buildName)) // docker build
 
 	for _, tag := range p.Build.Tags {
-		cmds = append(cmds, commandTag(p.Build, tag, buildName)) // docker tag
+		cmds = append(cmds, commandTag(p.Build, tag)) // docker tag
 
 		if !p.Dryrun {
 			cmds = append(cmds, commandPush(p.Build, tag)) // docker push
@@ -225,12 +225,12 @@ func (p Plugin) Exec() error {
 	}
 
 	// output the adaptive card
-	if err := p.writeCard(buildName); err != nil {
+	if err := p.writeCard(); err != nil {
 		fmt.Printf("Could not create adaptive card. %s\n", err)
 	}
 
 	if p.ArtifactFile != "" {
-		if digest, err := getDigest(buildName); err == nil {
+		if digest, err := getDigest(p.Build.TempTag); err == nil {
 			if err = drone.WritePluginArtifactFile(p.Daemon.RegistryType, p.ArtifactFile, p.Daemon.Registry, p.Build.Repo, digest, p.Build.Tags); err != nil {
 				fmt.Printf("failed to write plugin artifact file at path: %s with error: %s\n", p.ArtifactFile, err)
 			}
@@ -244,8 +244,8 @@ func (p Plugin) Exec() error {
 		// clear the slice
 		cmds = nil
 
-		cmds = append(cmds, commandRmi(buildName)) // docker rmi
+		cmds = append(cmds, commandRmi(p.Build.TempTag)) // docker rmi
-		cmds = append(cmds, commandPrune())        // docker system prune -f
+		cmds = append(cmds, commandPrune())              // docker system prune -f
 
 		for _, cmd := range cmds {
 			cmd.Stdout = os.Stdout
@@ -300,12 +300,12 @@ func commandInfo() *exec.Cmd {
 }
 
 // helper function to create the docker build command.
-func commandBuild(build Build, buildName string) *exec.Cmd {
+func commandBuild(build Build) *exec.Cmd {
 	args := []string{
 		"build",
 		"--rm=true",
 		"-f", build.Dockerfile,
-		"-t", buildName,
+		"-t", build.TempTag,
 	}
 
 	args = append(args, build.Context)
@@ -462,9 +462,9 @@ func hasProxyBuildArg(build *Build, key string) bool {
 }
 
 // helper function to create the docker tag command.
-func commandTag(build Build, tag, buildName string) *exec.Cmd {
+func commandTag(build Build, tag string) *exec.Cmd {
 	var (
-		source = buildName
+		source = build.TempTag
 		target = fmt.Sprintf("%s:%s", build.Repo, tag)
 	)
 	return exec.Command(

docker_test.go

@@ -16,6 +16,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "secret from env var",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				SecretEnvs: []string{
@@ -29,7 +30,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 				"--secret id=foo_secret,env=FOO_SECRET_ENV_VAR",
 			),
@@ -38,6 +39,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "secret from file",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				SecretFiles: []string{
@@ -51,7 +53,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 				"--secret id=foo_secret,src=/path/to/foo_secret",
 			),
@@ -60,6 +62,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "multiple mixed secrets",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				SecretEnvs: []string{
@@ -78,7 +81,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 				"--secret id=foo_secret,env=FOO_SECRET_ENV_VAR",
 				"--secret id=bar_secret,env=BAR_SECRET_ENV_VAR",
@@ -90,6 +93,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "invalid mixed secrets",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				SecretEnvs: []string{
@@ -110,7 +114,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 			),
 		},
@@ -118,6 +122,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "platform argument",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				Platform:   "test/platform",
@@ -129,7 +134,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 				"--platform",
 				"test/platform",
@@ -139,6 +144,7 @@ func TestCommandBuild(t *testing.T) {
 			name: "ssh agent",
 			build: Build{
 				Name:       "plugins/drone-docker:latest",
+				TempTag:    "abcdefgh",
 				Dockerfile: "Dockerfile",
 				Context:    ".",
 				SSHKeyPath: "id_rsa=/root/.ssh/id_rsa",
@@ -150,7 +156,7 @@ func TestCommandBuild(t *testing.T) {
 				"-f",
 				"Dockerfile",
 				"-t",
-				"plugins/drone-docker:latest",
+				"abcdefgh",
 				".",
 				"--ssh id_rsa=/root/.ssh/id_rsa",
 			),
@@ -161,7 +167,7 @@ func TestCommandBuild(t *testing.T) {
 		tc := tc
 
 		t.Run(tc.name, func(t *testing.T) {
-			cmd := commandBuild(tc.build, "plugins/drone-docker:latest")
+			cmd := commandBuild(tc.build)
 
 			if !reflect.DeepEqual(cmd.String(), tc.want.String()) {
 				t.Errorf("Got cmd %v, want %v", cmd, tc.want)