Windows Buildpackages

This change adds support for windows buildpackages by adding a
Package.Platform descriptor entry.  This allows you to declare an OS which, if
not specified defaults to "linux".  It also enables the pack experimental flag
for windows buildpackages.

Signed-off-by: Ben Hale <bhale@vmware.com>

README.md

@@ -119,13 +119,17 @@ package:
   include_dependencies: false
   register:             true
   registry_token:       ${{ secrets.JAVA_REGISTRY_TOKEN }}
+  platform:
+    os: linux
 ```
 
 * [Example `create-package.yml`](https://github.com/paketo-buildpacks/adopt-openjdk/blob/main/.github/workflows/create-package.yml)
 * [Example `test.yml`](https://github.com/paketo-buildpacks/adopt-openjdk/blob/main/.github/workflows/tests.yml)
 
 `package` is an object that describes the `repository` a buildpackage should be published to as well as whether to include the buildpackage's dependencies when creating it (`false` by default).  If defined, a `create-package` workflow is created that creates and publishes a new package when a release is published as well as adds a `create-package` job to the tests workflow that is run on each PR and each commit.  It will also add additional content to the draft release notes about the contents of the build package and will update the digest of the buildpackage in the published release notes.  If `register` is `true`, after the package is created, it is registered with the [Buildpack Registry Index](https://github.com/buildpacks/registry-index).
 
+`platform` describes what platform the created package should be built for. `os` can be set to `linux` or `windows` (`linux` by default).
+
 #### `builder`
 ```yaml
 builder:
@@ -212,10 +216,14 @@ path: ..
 offline_packages:
 - source: paketo-buildpacks/adopt-openjdk
   target: gcr.io/tanzu-buildpacks/adopt-openjdk
+  platform:
+    os: linux
 ```
 
 `offline_packages` is a list of objects that describe a `source` GitHub repository and a `target` Docker registry location.  If defined, each object will create a `create-package` workflow that is responsible for detecting a new online buildpackage release and creating a matching offline buildpackage release and publishing it.
 
+`platform` describes what platform the created package should be built for. `os` can be set to `linux` or `windows` (`linux` by default).
+
 #### `actions`
 ```yaml
 actions:

octo/create-package.sh

@@ -15,4 +15,4 @@ else
 fi
 
 [[ -e package.toml ]] && cp package.toml "${HOME}"/package.toml
-printf '[buildpack]\nuri = "%s"' "${HOME}"/buildpack >> "${HOME}"/package.toml
+printf '[buildpack]\nuri = "%s"\n\n[platform]\nos = "%s"\n' "${HOME}"/buildpack "${OS}" >> "${HOME}"/package.toml

octo/create_package.go

@@ -35,6 +35,17 @@ func ContributeCreatePackage(descriptor Descriptor) (*Contribution, error) {
 		return nil, nil
 	}
 
+	file := filepath.Join(descriptor.Path, "buildpack.toml")
+	s, err := ioutil.ReadFile(file)
+	if err != nil {
+		return nil, fmt.Errorf("unable to read %s\n%w", file, err)
+	}
+
+	var b libcnb.Buildpack
+	if err := toml.Unmarshal(s, &b); err != nil {
+		return nil, fmt.Errorf("unable to decode %s\n%w", file, err)
+	}
+
 	w := actions.Workflow{
 		Name: "Create Package",
 		On: map[event.Type]event.Event{
@@ -67,6 +78,11 @@ func ContributeCreatePackage(descriptor Descriptor) (*Contribution, error) {
 						Run:  StatikString("/install-pack.sh"),
 						Env:  map[string]string{"PACK_VERSION": PackVersion},
 					},
+					{
+						Name: "Enable pack Experimental",
+						If:   fmt.Sprintf("${{ %t }}", descriptor.Package.Platform.OS == PlatformWindows),
+						Run:  StatikString("/enable-pack-experimental.sh"),
+					},
 					{
 						Uses: "actions/checkout@v2",
 					},
@@ -92,6 +108,7 @@ func ContributeCreatePackage(descriptor Descriptor) (*Contribution, error) {
 						Run:  StatikString("/create-package.sh"),
 						Env: map[string]string{
 							"INCLUDE_DEPENDENCIES": strconv.FormatBool(descriptor.Package.IncludeDependencies),
+							"OS":                   descriptor.Package.Platform.OS,
 							"VERSION":              "${{ steps.version.outputs.version }}",
 						},
 					},
@@ -113,6 +130,16 @@ func ContributeCreatePackage(descriptor Descriptor) (*Contribution, error) {
 							"GITHUB_TOKEN": descriptor.GitHub.Token,
 						},
 					},
+					{
+						Uses: "docker://ghcr.io/buildpacks/actions/registry:main",
+						If:   fmt.Sprintf("${{ %t }}", descriptor.Package.Register),
+						With: map[string]interface{}{
+							"token":   descriptor.Package.RegistryToken,
+							"id":      b.Info.ID,
+							"version": "${{ steps.version.outputs.version }}",
+							"address": fmt.Sprintf("%s@${{ steps.package.outputs.digest }}", descriptor.Package.Repository),
+						},
+					},
 				},
 			},
 		},
@@ -121,30 +148,6 @@ func ContributeCreatePackage(descriptor Descriptor) (*Contribution, error) {
 	j := w.Jobs["create-package"]
 	j.Steps = append(NewDockerCredentialActions(descriptor.DockerCredentials), j.Steps...)
 	j.Steps = append(NewHttpCredentialActions(descriptor.HttpCredentials), j.Steps...)
-
-	if descriptor.Package.Register {
-		file := filepath.Join(descriptor.Path, "buildpack.toml")
-		s, err := ioutil.ReadFile(file)
-		if err != nil {
-			return nil, fmt.Errorf("unable to read %s\n%w", file, err)
-		}
-
-		var b libcnb.Buildpack
-		if err := toml.Unmarshal(s, &b); err != nil {
-			return nil, fmt.Errorf("unable to decode %s\n%w", file, err)
-		}
-
-		j.Steps = append(j.Steps, actions.Step{
-			Uses: "docker://ghcr.io/buildpacks/actions/registry:main",
-			With: map[string]interface{}{
-				"token":   descriptor.Package.RegistryToken,
-				"id":      b.Info.ID,
-				"version": "${{ steps.version.outputs.version }}",
-				"address": fmt.Sprintf("%s@${{ steps.package.outputs.digest }}", descriptor.Package.Repository),
-			},
-		})
-	}
-
 	w.Jobs["create-package"] = j
 
 	c, err := NewActionContribution(w)

octo/descriptor.go

@@ -80,15 +80,26 @@ type Dependency struct {
 }
 
 type OfflinePackage struct {
-	Source string
-	Target string
+	Source   string
+	Target   string
+	Platform Platform
 }
 
 type Package struct {
 	Repository          string
 	IncludeDependencies bool `yaml:"include_dependencies"`
 	Register            bool
 	RegistryToken       string `yaml:"registry_token"`
+	Platform            Platform
+}
+
+const (
+	PlatformLinux   = "linux"
+	PlatformWindows = "windows"
+)
+
+type Platform struct {
+	OS string
 }
 
 type Test struct {
@@ -133,6 +144,17 @@ func NewDescriptor(path string) (Descriptor, error) {
 		}
 	}
 
+	if d.Package != nil && d.Package.Platform.OS == "" {
+		d.Package.Platform.OS = PlatformLinux
+	}
+
+	for i, o := range d.OfflinePackages {
+		if o.Platform.OS == "" {
+			o.Platform.OS = PlatformLinux
+			d.OfflinePackages[i] = o
+		}
+	}
+
 	if d.Test.Steps == nil {
 		d.Test.Steps = []actions.Step{
 			{

octo/enable-pack-experimental.sh

@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+echo "Enabling pack experimental features"
+
+mkdir -p "${HOME}"/.pack
+echo "experimental = true" >> "${HOME}"/.pack/config.toml

octo/offline_packages.go

@@ -99,12 +99,18 @@ func contributeOfflinePackage(descriptor Descriptor, offlinePackage OfflinePacka
 						Run:  StatikString("/install-pack.sh"),
 						Env:  map[string]string{"PACK_VERSION": PackVersion},
 					},
+					{
+						Name: "Enable pack Experimental",
+						If:   fmt.Sprintf("${{ %t }}", offlinePackage.Platform.OS == PlatformWindows),
+						Run:  StatikString("/enable-pack-experimental.sh"),
+					},
 					{
 						Name: "Create Package",
 						If:   "${{ ! steps.version.outputs.skip }}",
 						Run:  StatikString("/create-package.sh"),
 						Env: map[string]string{
 							"INCLUDE_DEPENDENCIES": "true",
+							"OS":                   descriptor.Package.Platform.OS,
 							"VERSION":              "${{ steps.version.outputs.version }}",
 						},
 					},

octo/test.go

@@ -119,6 +119,11 @@ func ContributeTest(descriptor Descriptor) (*Contribution, error) {
 					Run:  StatikString("/install-pack.sh"),
 					Env:  map[string]string{"PACK_VERSION": PackVersion},
 				},
+				{
+					Name: "Enable pack Experimental",
+					If:   fmt.Sprintf("${{ %t }}", descriptor.Package.Platform.OS == PlatformWindows),
+					Run:  StatikString("/enable-pack-experimental.sh"),
+				},
 				{
 					Uses: "actions/setup-go@v2",
 					With: map[string]interface{}{"go-version": GoVersion},
@@ -147,6 +152,7 @@ func ContributeTest(descriptor Descriptor) (*Contribution, error) {
 					Run:  StatikString("/create-package.sh"),
 					Env: map[string]string{
 						"INCLUDE_DEPENDENCIES": "true",
+						"OS":                   descriptor.Package.Platform.OS,
 						"VERSION":              "${{ steps.version.outputs.version }}",
 					},
 				},