Enable architecture specific dependencies

go.mod

@@ -14,6 +14,7 @@ require (
 	github.com/dsnet/compress v0.0.2-0.20210315054119-f66993602bf5
 	github.com/gabriel-vasile/mimetype v1.4.7
 	github.com/google/uuid v1.6.0
+	github.com/onsi/ginkgo v1.16.5 // indirect
 	github.com/onsi/gomega v1.34.1
 	github.com/pelletier/go-toml v1.9.5
 	github.com/sclevine/spec v1.4.0

go.sum

@@ -1108,6 +1108,7 @@ github.com/fsnotify/fsnotify v1.4.7/go.mod h1:jwhsz4b93w/PPRr/qN1Yymfu8t87LnFCMo
 github.com/fsnotify/fsnotify v1.4.9/go.mod h1:znqG4EE+3YCdAaPaxE2ZRY/06pZUdp0tY4IgpuI1SZQ=
 github.com/fsnotify/fsnotify v1.5.1/go.mod h1:T3375wBYaZdLLcVNkcVbzGHY7f1l/uK5T5Ai1i3InKU=
 github.com/fsnotify/fsnotify v1.5.4/go.mod h1:OVB6XrOHzAwXMpEM7uPOzcehqUV2UqJxmVXmkdnm1bU=
+github.com/fsnotify/fsnotify v1.6.0 h1:n+5WquG0fcWoWp6xPWfHdbskMCQaFnG6PfBrh1Ky4HY=
 github.com/fsnotify/fsnotify v1.6.0/go.mod h1:sl3t1tCWJFWoRz9R8WJCbQihKKwmorjAbSClcnxKAGw=
 github.com/fullsailor/pkcs7 v0.0.0-20190404230743-d7302db945fa/go.mod h1:KnogPXtdwXqoenmZCw6S+25EAm2MkxbG0deNDu4cbSA=
 github.com/fxamacker/cbor/v2 v2.4.0/go.mod h1:TA1xS00nchWmaBnEIxPSE5oHLuJBAVvqrtAnWBwBCVo=
@@ -1657,6 +1658,7 @@ github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLA
 github.com/nwaples/rardecode v1.1.0 h1:vSxaY8vQhOcVr4mm5e8XllHWTiM4JF507A0Katqw7MQ=
 github.com/nwaples/rardecode v1.1.0/go.mod h1:5DzqNKiOdpKKBH87u8VlvAnPZMXcGRhxWkRpHbbfGS0=
 github.com/nxadm/tail v1.4.4/go.mod h1:kenIhsEOeOJmVchQTgglprH7qJGnHDVpk1VPCcaMI8A=
+github.com/nxadm/tail v1.4.8 h1:nPr65rt6Y5JFSKQO7qToXr7pePgD6Gwiw05lkbyAQTE=
 github.com/nxadm/tail v1.4.8/go.mod h1:+ncqLTQzXmGhMZNUePPaPqPvBxHAIsmXswZKocGu+AU=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/olekukonko/tablewriter v0.0.0-20170122224234-a0225b3f23b5/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=
@@ -3100,6 +3102,7 @@ gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/square/go-jose.v2 v2.2.2/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
 gopkg.in/square/go-jose.v2 v2.3.1/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
 gopkg.in/square/go-jose.v2 v2.5.1/go.mod h1:M9dMgbHiYLoDGQrXy7OpJDJWiKiU//h+vD76mk0e1AI=
+gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7 h1:uRGJdciOHaEIrze2W8Q3AKkepLTh2hOroT7a+7czfdQ=
 gopkg.in/tomb.v1 v1.0.0-20141024135613-dd632973f1e7/go.mod h1:dt/ZhP58zS4L8KSrWDmTeBkI65Dw0HsyUHuEVlX15mw=
 gopkg.in/warnings.v0 v0.1.2 h1:wFXVbFY8DY5/xOe1ECiWdKCzZlxgshcYVNkBHstARME=
 gopkg.in/warnings.v0 v0.1.2/go.mod h1:jksf8JmL6Qr/oQM2OXTHunEvvTAsrWBLb6OOjuVWRNI=

postal/buildpack.go

@@ -74,6 +74,9 @@ type Dependency struct {
 	// StripComponents behaves like the --strip-components flag on tar command
 	// removing the first n levels from the final decompression destination.
 	StripComponents int `toml:"strip-components"`
+
+	// ARCH is the architecture of this dependency
+	Arch string `toml:"arch"`
 }
 
 func parseBuildpack(path, name string) ([]Dependency, string, error) {

postal/service.go

@@ -4,8 +4,10 @@ import (
 	"errors"
 	"fmt"
 	"io"
+	"os"
 	"path/filepath"
 	"regexp"
+	"runtime"
 	"sort"
 	"strings"
 	"time"
@@ -52,15 +54,17 @@ type ErrNoDeps struct {
 	id                string
 	version           string
 	stack             string
+	arch              string
 	supportedVersions []string
 }
 
 // Error implements the error.Error interface
 func (e *ErrNoDeps) Error() string {
-	return fmt.Sprintf("failed to satisfy %q dependency version constraint %q: no compatible versions on %q stack. Supported versions are: [%s]",
+	return fmt.Sprintf("failed to satisfy %q dependency version constraint %q: no compatible versions on %q stack with architecture %q. Supported versions are: [%s]",
 		e.id,
 		e.version,
 		e.stack,
+		e.arch,
 		strings.Join(e.supportedVersions, ", "),
 	)
 }
@@ -147,6 +151,10 @@ func (s Service) Resolve(path, id, version, stack string) (Dependency, error) {
 			continue
 		}
 
+		if !isCorrectArch(dependency) {
+			continue
+		}
+
 		sVersion, err := semver.NewVersion(dependency.Version)
 		if err != nil {
 			return Dependency{}, err
@@ -160,7 +168,7 @@ func (s Service) Resolve(path, id, version, stack string) (Dependency, error) {
 	}
 
 	if len(compatibleVersions) == 0 {
-		return Dependency{}, &ErrNoDeps{id, version, stack, supportedVersions}
+		return Dependency{}, &ErrNoDeps{id, version, stack, archFromSystem(), supportedVersions}
 	}
 
 	stacksForVersion := map[string][]string{}
@@ -220,6 +228,25 @@ func (s Service) Resolve(path, id, version, stack string) (Dependency, error) {
 	return compatibleVersions[0], nil
 }
 
+func isCorrectArch(dep Dependency) bool {
+	systemArch := archFromSystem()
+
+	if systemArch == "amd64" && dep.Arch == "" {
+		return true
+	}
+
+	return systemArch == dep.Arch
+}
+
+func archFromSystem() string {
+	archFromEnv, ok := os.LookupEnv("BP_ARCH")
+	if !ok {
+		archFromEnv = runtime.GOARCH
+	}
+
+	return archFromEnv
+}
+
 func stringSliceContains(slice []string, str string) bool {
 	for _, s := range slice {
 		if s == str {

postal/service_test.go

@@ -23,6 +23,7 @@ import (
 	//nolint Ignore SA1019, usage of deprecated package within a deprecated test case
 	"github.com/paketo-buildpacks/packit/v2/paketosbom"
 
+	. "github.com/onsi/ginkgo"
 	. "github.com/onsi/gomega"
 )
 
@@ -115,6 +116,12 @@ strip-components = 1
 		service = postal.NewService(transport).
 			WithDependencyMappingResolver(mappingResolver).
 			WithDependencyMirrorResolver(mirrorResolver)
+
+		Expect(os.Setenv("BP_ARCH", "amd64")).To(Succeed())
+	})
+
+	AfterEach(func() {
+		Expect(os.Unsetenv("BP_ARCH")).To(Succeed())
 	})
 
 	context("Resolve", func() {
@@ -310,6 +317,85 @@ version = "4.5.6"
 			})
 		})
 
+		context("when there architecture specific versions", func() {
+			it.Before(func() {
+				err := os.WriteFile(path, []byte(`
+[metadata]
+[metadata.default-versions]
+some-entry = "1.2.x"
+
+[[metadata.dependencies]]
+id = "some-entry"
+sha256 = "some-sha-amd64"
+stacks = ["*"]
+uri = "some-uri"
+version = "1.2.3"
+arch = "amd64"
+
+[[metadata.dependencies]]
+id = "some-entry"
+sha256 = "some-sha-arm"
+stacks = ["*"]
+uri = "some-uri"
+version = "1.2.3"
+arch = "arm"
+
+[[metadata.dependencies]]
+id = "some-other-entry"
+sha256 = "some-other-sha"
+stacks = ["*"]
+uri = "some-uri"
+version = "1.2.4"
+
+`), 0600)
+				Expect(err).NotTo(HaveOccurred())
+			})
+
+			context("BP_ARCH=amd64", func() {
+				it.Before(func() {
+					Expect(os.Setenv("BP_ARCH", "amd64")).To(Succeed())
+				})
+
+				it.After(func() {
+					Expect(os.Unsetenv("BP_ARCH")).To(Succeed())
+				})
+
+				it("picks the dependency with the correct arch", func() {
+					dependency, err := service.Resolve(path, "some-entry", "1.2.3", "some-stack")
+					Expect(err).NotTo(HaveOccurred())
+					Expect(dependency.SHA256).To(Equal("some-sha-amd64"))
+				})
+
+				it("picks the dependency with the no arch", func() {
+					dependency, err := service.Resolve(path, "some-other-entry", "1.2.4", "some-stack")
+					Expect(err).NotTo(HaveOccurred())
+					Expect(dependency.SHA256).To(Equal("some-other-sha"))
+				})
+			})
+
+			context("BP_ARCH=arm", func() {
+				it.Before(func() {
+					Expect(os.Setenv("BP_ARCH", "arm")).To(Succeed())
+				})
+
+				it.After(func() {
+					Expect(os.Unsetenv("BP_ARCH")).To(Succeed())
+				})
+
+				it("picks the dependency with the correct arch", func() {
+					dependency, err := service.Resolve(path, "some-entry", "1.2.3", "some-stack")
+					Expect(err).NotTo(HaveOccurred())
+					Expect(dependency.SHA256).To(Equal("some-sha-arm"))
+				})
+
+				it("fails if no dependency with the correct arch is found", func() {
+					_, err := service.Resolve(path, "some-other-entry", "1.2.4", "some-stack")
+					Expect(err).To(MatchError(ContainSubstring("failed to satisfy")))
+					Expect(err).To(MatchError(ContainSubstring("\"arm\"")))
+				})
+			})
+		})
+
 		context("when both a wildcard stack constraint and a specific stack constraint exist for the same dependency version", func() {
 			it.Before(func() {
 				err := os.WriteFile(path, []byte(`
@@ -429,7 +515,7 @@ version = "1.2.3"
 					expectedErr := &postal.ErrNoDeps{}
 					_, err := service.Resolve(path, "some-entry", "9.9.9", "some-stack")
 					Expect(errors.As(err, &expectedErr)).To(BeTrue())
-					Expect(err).To(MatchError(ContainSubstring("failed to satisfy \"some-entry\" dependency version constraint \"9.9.9\": no compatible versions on \"some-stack\" stack. Supported versions are: [1.2.3, 4.5.6]")))
+					Expect(err).To(MatchError(ContainSubstring("failed to satisfy \"some-entry\" dependency version constraint \"9.9.9\": no compatible versions on \"some-stack\" stack with architecture \"amd64\". Supported versions are: [1.2.3, 4.5.6]")))
 				})
 			})
 		})