allowing to create a builder with other architecture available for li…

…fecycle

Signed-off-by: Juan Bustamante <jbustamante@vmware.com>

internal/builder/lifecycle.go

@@ -120,3 +120,8 @@ func (l *lifecycle) binaries() []string {
 	}
 	return binaries
 }
+
+// SupportedLinuxArchitecture returns true for each binary architecture available at https://github.com/buildpacks/lifecycle/releases/
+func SupportedLinuxArchitecture(arch string) bool {
+	return arch == "arm64" || arch == "ppc64le" || arch == "s390x"
+}

pkg/client/create_builder.go

@@ -254,14 +254,14 @@ func (c *Client) fetchLifecycle(ctx context.Context, config pubbldr.LifecycleCon
 			return nil, errors.Wrapf(err, "%s must be a valid semver", style.Symbol("lifecycle.version"))
 		}
 
-		uri = uriFromLifecycleVersion(*v, os, architecture)
+		uri = c.uriFromLifecycleVersion(*v, os, architecture)
 	case config.URI != "":
 		uri, err = paths.FilePathToURI(config.URI, relativeBaseDir)
 		if err != nil {
 			return nil, err
 		}
 	default:
-		uri = uriFromLifecycleVersion(*semver.MustParse(builder.DefaultLifecycleVersion), os, architecture)
+		uri = c.uriFromLifecycleVersion(*semver.MustParse(builder.DefaultLifecycleVersion), os, architecture)
 	}
 
 	blob, err := c.downloader.Download(ctx, uri)
@@ -405,15 +405,20 @@ func validateModule(kind string, module buildpack.BuildModule, source, expectedI
 	return nil
 }
 
-func uriFromLifecycleVersion(version semver.Version, os string, architecture string) string {
+func (c *Client) uriFromLifecycleVersion(version semver.Version, os string, architecture string) string {
 	arch := "x86-64"
 
 	if os == "windows" {
 		return fmt.Sprintf("https://github.com/buildpacks/lifecycle/releases/download/v%s/lifecycle-v%s+windows.%s.tgz", version.String(), version.String(), arch)
 	}
 
-	if architecture == "arm64" {
+	if builder.SupportedLinuxArchitecture(architecture) {
 		arch = architecture
+	} else {
+		// TODO: Do we want to fail in this case instead of a warning?
+		// I added the warning to help the buildpack authors understand if they builder ended up with a wrong
+		// lifecycle binary.
+		c.logger.Warnf("trying to download a lifecycle binary for an unsupported architecture: %s, using default %s", style.Symbol(architecture), style.Symbol(arch))
 	}
 
 	return fmt.Sprintf("https://github.com/buildpacks/lifecycle/releases/download/v%s/lifecycle-v%s+linux.%s.tgz", version.String(), version.String(), arch)

pkg/image/fetcher.go

@@ -197,6 +197,7 @@ func (f *Fetcher) fetchRemoteImage(name string, target *dist.Target) (imgutil.Im
 				f.logger.Warnf("trying to fetch an image with more than one OS distribution, using %s", style.Symbol(target.Distributions[0].Version))
 			}
 		}
+		f.logger.Debugf("Fetching image %s with platform %v", style.Symbol(name), platform)
 		image, err = remote.NewImage(name, f.keychain, remote.FromBaseImage(name), remote.WithDefaultPlatform(platform))
 	}