Allow to customize publish.Namer

Fixes ko-build#476

pkg/commands/options/namer_test.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2021 Google LLC All Rights Reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package options_test
+
+import (
+	"path"
+	"testing"
+
+	"github.com/google/ko/pkg/commands/options"
+)
+
+func TestMakeNamer(t *testing.T) {
+	for _, namerCase := range testMakeNamerCases() {
+		namerCase := namerCase
+		t.Run(namerCase.name, func(t *testing.T) {
+			namer := options.MakeNamer(&namerCase.opts)
+			got := namer("registry.example.org/foo/bar", "example.org/sample/cmd/example")
+
+			if got != namerCase.want {
+				t.Errorf("got image name %s, wanted %s", got, namerCase.want)
+			}
+		})
+	}
+}
+
+func testMakeNamerCases() []testMakeNamerCase {
+	return []testMakeNamerCase{{
+		name: "defaults",
+		want: "registry.example.org/foo/bar/example-51d74b7127c5f7495a338df33ecdeb19",
+	}, {
+		name: "with different separator",
+		want: "registry.example.org/foo/bar-example-51d74b7127c5f7495a338df33ecdeb19",
+		opts: options.PublishOptions{ImageNameSeparator: "-"},
+	}, {
+		name: "with preserve import paths",
+		want: "registry.example.org/foo/bar/example.org/sample/cmd/example",
+		opts: options.PublishOptions{PreserveImportPaths: true},
+	}, {
+		name: "with base import paths",
+		want: "registry.example.org/foo/bar/example",
+		opts: options.PublishOptions{BaseImportPaths: true},
+	}, {
+		name: "with base import paths and custom separator",
+		want: "registry.example.org/foo/bar-example",
+		opts: options.PublishOptions{BaseImportPaths: true, ImageNameSeparator: "-"},
+	}, {
+		name: "with bare",
+		want: "registry.example.org/foo/bar",
+		opts: options.PublishOptions{Bare: true},
+	}, {
+		name: "with custom namer",
+		want: "registry.example.org/foo/bar!example",
+		opts: options.PublishOptions{ImageNamer: func(base string, importpath string) string {
+			return base + "!" + path.Base(importpath)
+		}},
+	}}
+}
+
+type testMakeNamerCase struct {
+	name string
+	opts options.PublishOptions
+	want string
+}

pkg/commands/options/publish.go

@@ -21,6 +21,7 @@ import (
 	"encoding/hex"
 	"os"
 	"path"
+	"strings"
 
 	"github.com/google/go-containerregistry/pkg/v1/daemon"
 	"github.com/google/ko/pkg/publish"
@@ -65,6 +66,14 @@ type PublishOptions struct {
 	BaseImportPaths bool
 	// Bare uses a tag on the KO_DOCKER_REPO without anything additional.
 	Bare bool
+	// ImageNameSeparator is used to create the image name from base repo and
+	// specific import path.
+	ImageNameSeparator string
+
+	// ImageNamer can be used to pass a custom image name function. When given
+	// PreserveImportPaths, BaseImportPaths, Bare, and ImageNameSeparator has
+	// no effect.
+	ImageNamer publish.Namer
 }
 
 func AddPublishArg(cmd *cobra.Command, po *PublishOptions) {
@@ -96,33 +105,52 @@ func AddPublishArg(cmd *cobra.Command, po *PublishOptions) {
 		"Whether to use the base path without MD5 hash after KO_DOCKER_REPO (may not work properly with --tags).")
 	cmd.Flags().BoolVar(&po.Bare, "bare", po.Bare,
 		"Whether to just use KO_DOCKER_REPO without additional context (may not work properly with --tags).")
+	cmd.Flags().StringVar(&po.ImageNameSeparator, "image-name-separator", defaultImageNameSeparator,
+		"A separator to be used to concatenate KO_DOCKER_REPO with specific image name.")
 }
 
-func packageWithMD5(base, importpath string) string {
+const defaultImageNameSeparator = "/"
+
+func pathJoin(sep string, paths ...string) string {
+	if sep == "" {
+		sep = defaultImageNameSeparator
+	}
+	for i, e := range paths {
+		if e != "" {
+			return path.Clean(strings.Join(paths[i:], sep))
+		}
+	}
+	return ""
+}
+
+func (po *PublishOptions) packageWithMD5(base, importpath string) string {
 	hasher := md5.New() //nolint: gosec // No strong cryptography needed.
 	hasher.Write([]byte(importpath))
-	return path.Join(base, path.Base(importpath)+"-"+hex.EncodeToString(hasher.Sum(nil)))
+	return pathJoin(po.ImageNameSeparator,
+		base, path.Base(importpath)+"-"+hex.EncodeToString(hasher.Sum(nil)))
 }
 
-func preserveImportPath(base, importpath string) string {
-	return path.Join(base, importpath)
+func (po *PublishOptions) preserveImportPath(base, importpath string) string {
+	return pathJoin(po.ImageNameSeparator, base, importpath)
 }
 
-func baseImportPaths(base, importpath string) string {
-	return path.Join(base, path.Base(importpath))
+func (po *PublishOptions) baseImportPaths(base, importpath string) string {
+	return pathJoin(po.ImageNameSeparator, base, path.Base(importpath))
 }
 
 func bareDockerRepo(base, _ string) string {
 	return base
 }
 
 func MakeNamer(po *PublishOptions) publish.Namer {
-	if po.PreserveImportPaths {
-		return preserveImportPath
+	if po.ImageNamer != nil {
+		return po.ImageNamer
+	} else if po.PreserveImportPaths {
+		return po.preserveImportPath
 	} else if po.BaseImportPaths {
-		return baseImportPaths
+		return po.baseImportPaths
 	} else if po.Bare {
 		return bareDockerRepo
 	}
-	return packageWithMD5
+	return po.packageWithMD5
 }