Improve Dockerfile fetching error reporting and "bashbrew children" / "bashbrew from" handling (especially in the case of no "--apply-constraints" flag)

Author: tianon

bashbrew/go/src/bashbrew/cmd-deps.go

@@ -67,13 +67,20 @@ func cmdFamily(parents bool, c *cli.Context) error {
 				continue
 			}
 
-			froms, err := r.DockerFroms(entry)
-			if err != nil {
-				return cli.NewMultiError(fmt.Errorf(`failed fetching/scraping FROM for %q (tags %q)`, r.RepoName, entry.TagsString()), err)
+			entryArches := []string{arch}
+			if !applyConstraints {
+				entryArches = entry.Architectures
 			}
-			for _, from := range froms {
-				for _, tag := range r.Tags("", false, entry) {
-					network.AddEdge(from, tag)
+
+			for _, entryArch := range entryArches {
+				froms, err := r.ArchDockerFroms(entryArch, entry)
+				if err != nil {
+					return cli.NewMultiError(fmt.Errorf(`failed fetching/scraping FROM for %q (tags %q, arch %q)`, r.RepoName, entry.TagsString(), entryArch), err)
+				}
+				for _, from := range froms {
+					for _, tag := range r.Tags("", false, entry) {
+						network.AddEdge(from, tag)
+					}
 				}
 			}
 		}

bashbrew/go/src/bashbrew/cmd-from.go

@@ -28,9 +28,26 @@ func cmdFrom(c *cli.Context) error {
 				continue
 			}
 
-			froms, err := r.DockerFroms(entry)
-			if err != nil {
-				return cli.NewMultiError(fmt.Errorf(`failed fetching/scraping FROM for %q (tags %q)`, r.RepoName, entry.TagsString()), err)
+			entryArches := []string{arch}
+			if !applyConstraints {
+				entryArches = entry.Architectures
+			}
+
+			froms := []string{}
+			for _, entryArch := range entryArches {
+				archFroms, err := r.ArchDockerFroms(entryArch, entry)
+				if err != nil {
+					return cli.NewMultiError(fmt.Errorf(`failed fetching/scraping FROM for %q (tags %q, arch %q)`, r.RepoName, entry.TagsString(), entryArch), err)
+				}
+			ArchFroms:
+				for _, archFrom := range archFroms {
+					for _, from := range froms {
+						if from == archFrom {
+							continue ArchFroms
+						}
+					}
+					froms = append(froms, archFrom)
+				}
 			}
 
 			fromsString := strings.Join(froms, " ")

bashbrew/go/src/bashbrew/docker.go

@@ -55,7 +55,7 @@ var dockerfileMetadataCache = map[string]*dockerfileMetadata{}
 func (r Repo) archDockerfileMetadata(arch string, entry *manifest.Manifest2822Entry) (*dockerfileMetadata, error) {
 	commit, err := r.fetchGitRepo(arch, entry)
 	if err != nil {
-		return nil, err
+		return nil, cli.NewMultiError(fmt.Errorf("failed fetching Git repo for arch %q from entry %q", arch, entry.String()), err)
 	}
 
 	dockerfileFile := path.Join(entry.ArchDirectory(arch), entry.ArchFile(arch))
@@ -70,17 +70,17 @@ func (r Repo) archDockerfileMetadata(arch string, entry *manifest.Manifest2822En
 
 	dockerfile, err := gitShow(commit, dockerfileFile)
 	if err != nil {
-		return nil, err
+		return nil, cli.NewMultiError(fmt.Errorf(`failed "git show" for %q from commit %q`, dockerfileFile, commit), err)
 	}
 	defer dockerfile.Close()
 
 	meta, err := parseDockerfileMetadata(dockerfile)
 	if err != nil {
-		return nil, err
+		return nil, cli.NewMultiError(fmt.Errorf(`failed parsing Dockerfile metadata for %q from commit %q`, dockerfileFile, commit), err)
 	}
 
 	if err := dockerfile.Close(); err != nil {
-		return nil, err
+		return nil, cli.NewMultiError(fmt.Errorf(`failed closing "git show" for %q from commit %q`, dockerfileFile, commit), err)
 	}
 
 	dockerfileMetadataCache[cacheKey] = meta