ability to disable purge

cmd/drone-docker/main.go

@@ -192,6 +192,11 @@ func main() {
 			Usage:  "docker email",
 			EnvVar: "PLUGIN_EMAIL,DOCKER_EMAIL",
 		},
+		cli.BoolTFlag{
+			Name:   "docker.purge",
+			Usage:  "docker should cleanup images",
+			EnvVar: "PLUGIN_PURGE",
+		},
 		cli.StringFlag{
 			Name:   "repo.branch",
 			Usage:  "repository default branch",
@@ -207,6 +212,7 @@ func main() {
 func run(c *cli.Context) error {
 	plugin := docker.Plugin{
 		Dryrun:  c.Bool("dry-run"),
+		Cleanup: c.Bool("purge"),
 		Login: docker.Login{
 			Registry: c.String("docker.registry"),
 			Username: c.String("docker.username"),
@@ -255,7 +261,6 @@ func run(c *cli.Context) error {
 			)
 		} else {
 			logrus.Printf("skipping automated docker build for %s", c.String("commit.ref"))
-
 			return nil
 		}
 	}

docker.go

@@ -57,27 +57,10 @@ type (
 		Build   Build  // Docker build configuration
 		Daemon  Daemon // Docker daemon configuration
 		Dryrun  bool   // Docker push is skipped
+		Cleanup bool   // Docker purge is enabled
 	}
 )
 
-func stripHeadPrefix(ref string) string {
-	ref = strings.TrimPrefix(ref, "refs/heads/")
-	return ref
-}
-
-// UseDefaultTag for keep only default branch for latest tag
-func UseDefaultTag(ref, defaultBranch string) bool {
-	if strings.HasPrefix(ref, "refs/tags/") {
-		return true
-	}
-
-	if stripHeadPrefix(ref) == defaultBranch {
-		return true
-	}
-
-	return false
-}
-
 // Exec executes the plugin step
 func (p Plugin) Exec() error {
 	// start the Docker daemon server
@@ -140,8 +123,10 @@ func (p Plugin) Exec() error {
 		}
 	}
 
+	if p.Cleanup {
 		cmds = append(cmds, commandRmi(p.Build.Name)) // docker rmi
 		cmds = append(cmds, commandPrune())           // docker system prune -f
+	}
 
 	// execute all commands in batch mode.
 	for _, cmd := range cmds {

docker_test.go

@@ -1,67 +1 @@
 package docker
-
-import "testing"
-
-func Test_stripHeadPrefix(t *testing.T) {
-	type args struct {
-		ref string
-	}
-	tests := []struct {
-		args args
-		want string
-	}{
-		{
-			args: args{
-				ref: "refs/heads/master",
-			},
-			want: "master",
-		},
-	}
-	for _, tt := range tests {
-		if got := stripHeadPrefix(tt.args.ref); got != tt.want {
-			t.Errorf("stripHeadPrefix() = %v, want %v", got, tt.want)
-		}
-	}
-}
-
-func TestUseDefaultTag(t *testing.T) {
-	type args struct {
-		ref           string
-		defaultBranch string
-	}
-	tests := []struct {
-		name string
-		args args
-		want bool
-	}{
-		{
-			name: "latest tag for default branch",
-			args: args{
-				ref:           "refs/heads/master",
-				defaultBranch: "master",
-			},
-			want: true,
-		},
-		{
-			name: "build from tags",
-			args: args{
-				ref:           "refs/tags/v1.0.0",
-				defaultBranch: "master",
-			},
-			want: true,
-		},
-		{
-			name: "skip build for not default branch",
-			args: args{
-				ref:           "refs/heads/develop",
-				defaultBranch: "master",
-			},
-			want: false,
-		},
-	}
-	for _, tt := range tests {
-		if got := UseDefaultTag(tt.args.ref, tt.args.defaultBranch); got != tt.want {
-			t.Errorf("%q. UseDefaultTag() = %v, want %v", tt.name, got, tt.want)
-		}
-	}
-}

tags.go

@@ -53,6 +53,21 @@ func DefaultTags(ref string) []string {
 	}
 }
 
+// UseDefaultTag for keep only default branch for latest tag
+func UseDefaultTag(ref, defaultBranch string) bool {
+	if strings.HasPrefix(ref, "refs/tags/") {
+		return true
+	}
+	if stripHeadPrefix(ref) == defaultBranch {
+		return true
+	}
+	return false
+}
+
+func stripHeadPrefix(ref string) string {
+	return strings.TrimPrefix(ref, "refs/heads/")
+}
+
 func stripTagPrefix(ref string) string {
 	ref = strings.TrimPrefix(ref, "refs/tags/")
 	ref = strings.TrimPrefix(ref, "v")

tags_test.go

@@ -102,3 +102,67 @@ func TestDefaultTagSuffix(t *testing.T) {
 		}
 	}
 }
+
+func Test_stripHeadPrefix(t *testing.T) {
+	type args struct {
+		ref string
+	}
+	tests := []struct {
+		args args
+		want string
+	}{
+		{
+			args: args{
+				ref: "refs/heads/master",
+			},
+			want: "master",
+		},
+	}
+	for _, tt := range tests {
+		if got := stripHeadPrefix(tt.args.ref); got != tt.want {
+			t.Errorf("stripHeadPrefix() = %v, want %v", got, tt.want)
+		}
+	}
+}
+
+func TestUseDefaultTag(t *testing.T) {
+	type args struct {
+		ref           string
+		defaultBranch string
+	}
+	tests := []struct {
+		name string
+		args args
+		want bool
+	}{
+		{
+			name: "latest tag for default branch",
+			args: args{
+				ref:           "refs/heads/master",
+				defaultBranch: "master",
+			},
+			want: true,
+		},
+		{
+			name: "build from tags",
+			args: args{
+				ref:           "refs/tags/v1.0.0",
+				defaultBranch: "master",
+			},
+			want: true,
+		},
+		{
+			name: "skip build for not default branch",
+			args: args{
+				ref:           "refs/heads/develop",
+				defaultBranch: "master",
+			},
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		if got := UseDefaultTag(tt.args.ref, tt.args.defaultBranch); got != tt.want {
+			t.Errorf("%q. UseDefaultTag() = %v, want %v", tt.name, got, tt.want)
+		}
+	}
+}