Merge branch 'fix/1081-1108-buildpack-duplicates' of github.com:build…

…packs/pack into fix/1081-1108-buildpack-duplicates

acceptance/acceptance_test.go

@@ -338,16 +338,47 @@ func testWithoutSpecificBuilderRequirement(
 			})
 
 			when("--format file", func() {
-				it("creates the package", func() {
-					packageTomlPath := generatePackageTomlWithOS(t, assert, pack, tmpDir, simplePackageConfigFixtureName, imageManager.HostOS())
-					destinationFile := filepath.Join(tmpDir, "package.cnb")
-					output := pack.RunSuccessfully(
-						"buildpack", "package", destinationFile,
-						"--format", "file",
-						"-c", packageTomlPath,
-					)
-					assertions.NewOutputAssertionManager(t, output).ReportsPackageCreation(destinationFile)
-					h.AssertTarball(t, destinationFile)
+				when("the file extension is .cnb", func() {
+					it("creates the package with the same extension", func() {
+						packageTomlPath := generatePackageTomlWithOS(t, assert, pack, tmpDir, simplePackageConfigFixtureName, imageManager.HostOS())
+						destinationFile := filepath.Join(tmpDir, "package.cnb")
+						output := pack.RunSuccessfully(
+							"buildpack", "package", destinationFile,
+							"--format", "file",
+							"-c", packageTomlPath,
+						)
+						assertions.NewOutputAssertionManager(t, output).ReportsPackageCreation(destinationFile)
+						h.AssertTarball(t, destinationFile)
+					})
+				})
+				when("the file extension is empty", func() {
+					it("creates the package with a .cnb extension", func() {
+						packageTomlPath := generatePackageTomlWithOS(t, assert, pack, tmpDir, simplePackageConfigFixtureName, imageManager.HostOS())
+						destinationFile := filepath.Join(tmpDir, "package")
+						expectedFile := filepath.Join(tmpDir, "package.cnb")
+						output := pack.RunSuccessfully(
+							"buildpack", "package", destinationFile,
+							"--format", "file",
+							"-c", packageTomlPath,
+						)
+						assertions.NewOutputAssertionManager(t, output).ReportsPackageCreation(expectedFile)
+						h.AssertTarball(t, expectedFile)
+					})
+				})
+				when("the file extension is not .cnb", func() {
+					it("creates the package with the given extension but shows a warning", func() {
+						packageTomlPath := generatePackageTomlWithOS(t, assert, pack, tmpDir, simplePackageConfigFixtureName, imageManager.HostOS())
+						destinationFile := filepath.Join(tmpDir, "package.tar.gz")
+						output := pack.RunSuccessfully(
+							"buildpack", "package", destinationFile,
+							"--format", "file",
+							"-c", packageTomlPath,
+						)
+						assertOutput := assertions.NewOutputAssertionManager(t, output)
+						assertOutput.ReportsPackageCreation(destinationFile)
+						assertOutput.ReportsInvalidExtension(".gz")
+						h.AssertTarball(t, destinationFile)
+					})
 				})
 			})
 

acceptance/assertions/output.go

@@ -112,6 +112,12 @@ func (o OutputAssertionManager) ReportsPackageCreation(name string) {
 	o.assert.ContainsF(o.output, "Successfully created package '%s'", name)
 }
 
+func (o OutputAssertionManager) ReportsInvalidExtension(extension string) {
+	o.testObject.Helper()
+
+	o.assert.ContainsF(o.output, "'%s' is not a valid extension for a packaged buildpack. Packaged buildpacks must have a '.cnb' extension", extension)
+}
+
 func (o OutputAssertionManager) ReportsPackagePublished(name string) {
 	o.testObject.Helper()
 

internal/commands/buildpack_package.go

@@ -42,10 +42,11 @@ func BuildpackPackage(logger logging.Logger, cfg config.Config, client Buildpack
 		Use:     "package <name> --config <config-path>",
 		Short:   "Package a buildpack in OCI format.",
 		Args:    cobra.ExactValidArgs(1),
-		Example: "pack buildpack package my-buildpack --config ./package.toml",
+		Example: "pack buildpack package my-buildpack --config ./package.toml\npack buildpack package my-buildpack.cnb --config ./package.toml --f file",
 		Long: "buildpack package allows users to package (a) buildpack(s) into OCI format, which can then to be hosted in " +
-			"image repositories. You can also package a number of buildpacks together, to enable easier distribution of " +
-			"a set of buildpacks. Packaged buildpacks can be used as inputs to `pack build` (using the `--buildpack` flag), " +
+			"image repositories or persisted on disk as a '.cnb' file. You can also package a number of buildpacks " +
+			"together, to enable easier distribution of a set of buildpacks. " +
+			"Packaged buildpacks can be used as inputs to `pack build` (using the `--buildpack` flag), " +
 			"and they can be included in the configs used in `pack builder create` and `pack buildpack package`. For more " +
 			"on how to package a buildpack, see: https://buildpacks.io/docs/buildpack-author-guide/package-a-buildpack/.",
 		RunE: logError(logger, func(cmd *cobra.Command, args []string) error {
@@ -82,6 +83,15 @@ func BuildpackPackage(logger logging.Logger, cfg config.Config, client Buildpack
 				}
 			}
 			name := args[0]
+			if flags.Format == pack.FormatFile {
+				switch ext := filepath.Ext(name); ext {
+				case pack.CNBExtension:
+				case "":
+					name += pack.CNBExtension
+				default:
+					logger.Warnf("%s is not a valid extension for a packaged buildpack. Packaged buildpacks must have a %s extension", style.Symbol(ext), style.Symbol(pack.CNBExtension))
+				}
+			}
 			if err := client.PackageBuildpack(cmd.Context(), pack.PackageBuildpackOptions{
 				RelativeBaseDir: relativeBaseDir,
 				Name:            name,

internal/commands/buildpack_package_test.go

@@ -88,6 +88,40 @@ func testPackageCommand(t *testing.T, when spec.G, it spec.S) {
 				h.AssertEq(t, receivedOptions.Config, myConfig)
 			})
 
+			when("file format", func() {
+				when("extension is .cnb", func() {
+					it("does not modify the name", func() {
+						cmd := packageCommand(withBuildpackPackager(fakeBuildpackPackager))
+						cmd.SetArgs([]string{"test.cnb", "-f", "file"})
+						h.AssertNil(t, cmd.Execute())
+
+						receivedOptions := fakeBuildpackPackager.CreateCalledWithOptions
+						h.AssertEq(t, receivedOptions.Name, "test.cnb")
+					})
+				})
+				when("extension is empty", func() {
+					it("appends .cnb to the name", func() {
+						cmd := packageCommand(withBuildpackPackager(fakeBuildpackPackager))
+						cmd.SetArgs([]string{"test", "-f", "file"})
+						h.AssertNil(t, cmd.Execute())
+
+						receivedOptions := fakeBuildpackPackager.CreateCalledWithOptions
+						h.AssertEq(t, receivedOptions.Name, "test.cnb")
+					})
+				})
+				when("extension is something other than .cnb", func() {
+					it("does not modify the name but shows a warning", func() {
+						cmd := packageCommand(withBuildpackPackager(fakeBuildpackPackager), withLogger(logger))
+						cmd.SetArgs([]string{"test.tar.gz", "-f", "file"})
+						h.AssertNil(t, cmd.Execute())
+
+						receivedOptions := fakeBuildpackPackager.CreateCalledWithOptions
+						h.AssertEq(t, receivedOptions.Name, "test.tar.gz")
+						h.AssertContains(t, outBuf.String(), "'.gz' is not a valid extension for a packaged buildpack. Packaged buildpacks must have a '.cnb' extension")
+					})
+				})
+			})
+
 			when("there is a path flag", func() {
 				it("returns an error saying that it cannot be used with the config flag", func() {
 					myConfig := pubbldpkg.Config{

new_buildpack.go

@@ -15,8 +15,7 @@ import (
 )
 
 var (
-	bashBinBuild = `
-#!/usr/bin/env bash
+	bashBinBuild = `#!/usr/bin/env bash
 
 set -euo pipefail
 
@@ -26,8 +25,7 @@ plan_path="$3"
 
 exit 0
 `
-	bashBinDetect = `
-#!/usr/bin/env bash
+	bashBinDetect = `#!/usr/bin/env bash
 
 exit 0
 `

package_buildpack.go

@@ -22,6 +22,9 @@ const (
 
 	// Packaging indicator that format of output will be a file on the host filesystem.
 	FormatFile = "file"
+
+	// CNBExtension is the file extension for a cloud native buildpack tar archive
+	CNBExtension = ".cnb"
 )
 
 // PackageBuildpackOptions is a configuration object used to define