Forward-port v1 changes to v2

.github/pipeline-version

@@ -1 +1 @@
-1.19.0
+1.21.2

.github/workflows/synchronize-labels.yml

@@ -11,7 +11,7 @@ jobs:
         runs-on:
             - ubuntu-latest
         steps:
-            - uses: actions/checkout@v2
+            - uses: actions/checkout@v3
             - uses: micnncim/action-label-syncer@v1
               env:
                 GITHUB_TOKEN: ${{ secrets.IMPLEMENTATION_GITHUB_TOKEN }}

.github/workflows/tests.yml

@@ -10,15 +10,15 @@ jobs:
         runs-on:
             - ubuntu-latest
         steps:
-            - uses: actions/checkout@v2
-            - uses: actions/cache@v2
+            - uses: actions/checkout@v3
+            - uses: actions/cache@v3
               with:
                 key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
                 path: ${{ env.HOME }}/go/pkg/mod
                 restore-keys: ${{ runner.os }}-go-
-            - uses: actions/setup-go@v2
+            - uses: actions/setup-go@v3
               with:
-                go-version: "1.16"
+                go-version: "1.17"
             - name: Install richgo
               run: |
                 #!/usr/bin/env bash

.github/workflows/update-pipeline.yml

@@ -14,17 +14,17 @@ jobs:
         runs-on:
             - ubuntu-latest
         steps:
-            - uses: actions/setup-go@v2
+            - uses: actions/setup-go@v3
               with:
-                go-version: "1.16"
+                go-version: "1.17"
             - name: Install octo
               run: |
                 #!/usr/bin/env bash
 
                 set -euo pipefail
 
                 GO111MODULE=on go get -u -ldflags="-s -w" github.com/paketo-buildpacks/pipeline-builder/cmd/octo
-            - uses: actions/checkout@v2
+            - uses: actions/checkout@v3
             - name: Update Pipeline
               id: pipeline
               run: |
@@ -62,7 +62,7 @@ jobs:
               env:
                 DESCRIPTOR: .github/pipeline-descriptor.yml
                 GITHUB_TOKEN: ${{ secrets.IMPLEMENTATION_GITHUB_TOKEN }}
-            - uses: peter-evans/create-pull-request@v3
+            - uses: peter-evans/create-pull-request@v4
               with:
                 author: ${{ secrets.IMPLEMENTATION_GITHUB_USERNAME }} <${{ secrets.IMPLEMENTATION_GITHUB_USERNAME }}@users.noreply.github.com>
                 body: |-

build.go

@@ -25,6 +25,7 @@ import (
 	"strings"
 
 	"github.com/BurntSushi/toml"
+	"github.com/Masterminds/semver"
 
 	"github.com/buildpacks/libcnb/internal"
 	"github.com/buildpacks/libcnb/log"
@@ -77,6 +78,15 @@ type BuildResult struct {
 	Unmet []UnmetPlanEntry
 }
 
+// Constants to track minimum and maximum supported Buildpack API versions
+const (
+	// MinSupportedBPVersion indicates the minium supported version of the Buildpacks API
+	MinSupportedBPVersion = "0.5"
+
+	// MaxSupportedBPVersion indicates the maximum supported version of the Buildpacks API
+	MaxSupportedBPVersion = "0.8"
+)
+
 // NewBuildResult creates a new BuildResult instance, initializing empty fields.
 func NewBuildResult() BuildResult {
 	return BuildResult{
@@ -113,11 +123,6 @@ func Build(build BuildFunc, options ...Option) {
 		config = option(config)
 	}
 
-	if len(config.arguments) != 4 {
-		config.exitHandler.Error(fmt.Errorf("expected 3 arguments and received %d", len(config.arguments)-1))
-		return
-	}
-
 	var (
 		err  error
 		file string
@@ -150,16 +155,49 @@ func Build(build BuildFunc, options ...Option) {
 	}
 	config.logger.Debugf("Buildpack: %+v", ctx.Buildpack)
 
-	API := strings.TrimSpace(ctx.Buildpack.API)
-	if API != "0.5" && API != "0.6" && API != "0.7" {
-		config.exitHandler.Error(errors.New("this version of libcnb is only compatible with buildpack APIs 0.5, 0.6, and 0.7"))
+	API, err := semver.NewVersion(ctx.Buildpack.API)
+	if err != nil {
+		config.exitHandler.Error(errors.New("version cannot be parsed"))
 		return
 	}
 
-	ctx.Layers = Layers{config.arguments[1]}
+	compatVersionCheck, _ := semver.NewConstraint(fmt.Sprintf(">= %s, <= %s", MinSupportedBPVersion, MaxSupportedBPVersion))
+	if !compatVersionCheck.Check(API) {
+		config.exitHandler.Error(fmt.Errorf("this version of libcnb is only compatible with buildpack APIs >= %s, <= %s", MinSupportedBPVersion, MaxSupportedBPVersion))
+		return
+	}
+
+	var buildpackPlanPath string
+
+	if API.LessThan(semver.MustParse("0.8")) {
+		if len(config.arguments) != 4 {
+			config.exitHandler.Error(fmt.Errorf("expected 3 arguments and received %d", len(config.arguments)-1))
+			return
+		}
+		ctx.Layers = Layers{config.arguments[1]}
+		ctx.Platform.Path = config.arguments[2]
+		buildpackPlanPath = config.arguments[3]
+	} else {
+		layersDir, ok := os.LookupEnv("CNB_LAYERS_DIR")
+		if !ok {
+			config.exitHandler.Error(fmt.Errorf("expected CNB_LAYERS_DIR to be set"))
+			return
+		}
+		ctx.Layers = Layers{layersDir}
+		ctx.Platform.Path, ok = os.LookupEnv("CNB_PLATFORM_DIR")
+		if !ok {
+			config.exitHandler.Error(fmt.Errorf("expected CNB_PLATFORM_DIR to be set"))
+			return
+		}
+		buildpackPlanPath, ok = os.LookupEnv("CNB_BP_PLAN_PATH")
+		if !ok {
+			config.exitHandler.Error(fmt.Errorf("expected CNB_BP_PLAN_PATH to be set"))
+			return
+		}
+	}
+
 	config.logger.Debugf("Layers: %+v", ctx.Layers)
 
-	ctx.Platform.Path = config.arguments[2]
 	if config.logger.IsDebugEnabled() {
 		config.logger.Debug(PlatformFormatter(ctx.Platform))
 	}
@@ -186,9 +224,8 @@ func Build(build BuildFunc, options ...Option) {
 	ctx.PersistentMetadata = store.Metadata
 	config.logger.Debugf("Persistent Metadata: %+v", ctx.PersistentMetadata)
 
-	file = config.arguments[3]
-	if _, err = toml.DecodeFile(file, &ctx.Plan); err != nil && !os.IsNotExist(err) {
-		config.exitHandler.Error(fmt.Errorf("unable to decode buildpack plan %s\n%w", file, err))
+	if _, err = toml.DecodeFile(buildpackPlanPath, &ctx.Plan); err != nil && !os.IsNotExist(err) {
+		config.exitHandler.Error(fmt.Errorf("unable to decode buildpack plan %s\n%w", buildpackPlanPath, err))
 		return
 	}
 	config.logger.Debugf("Buildpack Plan: %+v", ctx.Plan)
@@ -246,7 +283,7 @@ func Build(build BuildFunc, options ...Option) {
 		file = filepath.Join(ctx.Layers.Path, fmt.Sprintf("%s.toml", layer.Name))
 		config.logger.Debugf("Writing layer metadata: %s <= %+v", file, layer)
 		var toWrite interface{} = layer
-		if API == "0.5" {
+		if API.Equal(semver.MustParse("0.5")) {
 			toWrite = internal.LayerAPI5{
 				Build:    layer.LayerTypes.Build,
 				Cache:    layer.LayerTypes.Cache,
@@ -274,7 +311,7 @@ func Build(build BuildFunc, options ...Option) {
 		}
 	}
 
-	if API != "0.5" && API != "0.6" {
+	if API.GreaterThan(semver.MustParse("0.7")) || API.Equal(semver.MustParse("0.7")) {
 		if err := validateSBOMFormats(ctx.Layers.Path, ctx.Buildpack.Info.SBOMFormats); err != nil {
 			config.exitHandler.Error(fmt.Errorf("unable to validate SBOM\n%w", err))
 			return
@@ -291,14 +328,23 @@ func Build(build BuildFunc, options ...Option) {
 		file = filepath.Join(ctx.Layers.Path, "launch.toml")
 		config.logger.Debugf("Writing application metadata: %s <= %+v", file, launch)
 
-		if API == "0.5" {
+		if API.LessThan(semver.MustParse("0.6")) {
 			for _, process := range launch.Processes {
 				if process.Default {
 					config.exitHandler.Error(fmt.Errorf("unable to set default=true as that is not supported until API version 0.6"))
 				}
 			}
 		}
 
+		if API.LessThan(semver.MustParse("0.8")) {
+			for i, process := range launch.Processes {
+				if process.WorkingDirectory != "" {
+					config.exitHandler.Error(fmt.Errorf("unable to set working-directory=%s because that is not supported until API version 0.8", process.WorkingDirectory))
+					launch.Processes[i].WorkingDirectory = ""
+				}
+			}
+		}
+
 		if err = config.tomlWriter.Write(file, launch); err != nil {
 			config.exitHandler.Error(fmt.Errorf("unable to write application metadata %s\n%w", file, err))
 			return