Add without-download flag to update-stemcell

Allows Kiln to skip downloading a release if the remote source can
provide the SHA1 for the release tarball.

internal/commands/update_stemcell.go

@@ -12,16 +12,16 @@ import (
 
 	"github.com/pivotal-cf/kiln/internal/commands/flags"
 	"github.com/pivotal-cf/kiln/internal/component"
-	"github.com/pivotal-cf/kiln/pkg/cargo"
 )
 
 type UpdateStemcell struct {
 	Options struct {
 		flags.Standard
 
-		Version        string `short:"v"   long:"version"               required:"true"    description:"desired version of stemcell"`
-		ReleasesDir    string `short:"rd"  long:"releases-directory"    default:"releases" description:"path to a directory to download releases into"`
-		UpdateReleases bool   `short:"ur"  long:"update-releases"                          description:"finds latest matching releases for new stemcell version"`
+		Version         string `short:"v"   long:"version"               required:"true"    description:"desired version of stemcell"`
+		ReleasesDir     string `short:"rd"  long:"releases-directory"    default:"releases" description:"path to a directory to download releases into"`
+		UpdateReleases  bool   `short:"ur"  long:"update-releases"                          description:"finds latest matching releases for new stemcell version"`
+		WithoutDownload bool   `            long:"without-download"                         description:"updates stemcell releases without downloading releases"`
 	}
 	FS                         billy.Filesystem
 	MultiReleaseSourceProvider MultiReleaseSourceProvider
@@ -69,45 +69,46 @@ func (update UpdateStemcell) Execute(args []string) error {
 	releaseSource := update.MultiReleaseSourceProvider(kilnfile, false)
 
 	for i, rel := range kilnfileLock.Releases {
-		update.Logger.Printf("Updating release %q with stemcell %s %s...", rel.Name, kilnfileLock.Stemcell.OS, trimmedInputVersion)
+		update.Logger.Printf("Updating release %s %s with stemcell %s %s...", rel.Name, rel.Version, kilnfileLock.Stemcell.OS, trimmedInputVersion)
 
 		spec, err := kilnfile.BOSHReleaseTarballSpecification(rel.Name)
 		if err != nil {
 			return err
 		}
+
 		spec.StemcellOS = kilnfileLock.Stemcell.OS
 		spec.StemcellVersion = trimmedInputVersion
 
-		var remote cargo.BOSHReleaseTarballLock
-		if update.Options.UpdateReleases {
-			remote, err = releaseSource.FindReleaseVersion(spec, true)
-		} else {
+		if !update.Options.UpdateReleases {
 			spec.Version = rel.Version
-			remote, err = releaseSource.GetMatchedRelease(spec)
 		}
 
+		remote, err := releaseSource.FindReleaseVersion(spec, true)
 		if err != nil {
-			return fmt.Errorf("while finding release %q, encountered error: %w", rel.Name, err)
+			return fmt.Errorf("while finding release %s %s, encountered error: %w", rel.Name, rel.Version, err)
 		}
+
 		if component.IsErrNotFound(err) {
-			return fmt.Errorf("couldn't find release %q", rel.Name)
+			return fmt.Errorf("couldn't find release %s %s", rel.Name, rel.Version)
 		}
 
 		if remote.RemotePath == rel.RemotePath && remote.RemoteSource == rel.RemoteSource {
-			update.Logger.Printf("No change for release %q\n", rel.Name)
+			update.Logger.Printf("No change for release %s %s\n", rel.Name, rel.Version)
 			continue
 		}
-		lock := &kilnfileLock.Releases[i]
 
+		lock := &kilnfileLock.Releases[i]
 		lock.RemotePath = remote.RemotePath
 		lock.RemoteSource = remote.RemoteSource
 		lock.SHA1 = remote.SHA1
-		if remote.SHA1 == "" || remote.SHA1 == "not-calculated" {
+
+		if !update.Options.WithoutDownload || lock.SHA1 == "" || lock.SHA1 == "not-calculated" {
 			// release source needs to download.
 			local, err := releaseSource.DownloadRelease(update.Options.ReleasesDir, remote)
 			if err != nil {
-				return fmt.Errorf("while downloading release %q, encountered error: %w", rel.Name, err)
+				return fmt.Errorf("while downloading release %s %s, encountered error: %w", rel.Name, rel.Version, err)
 			}
+
 			lock.SHA1 = local.Lock.SHA1
 		}
 	}