Merge pull request #3242 from rrjjvv/new-bakefile-env-var

Allow bake files to be specified via environment variable

commands/bake.go

@@ -40,6 +40,11 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 )
 
+const (
+	bakeEnvFileSeparator = "BUILDX_BAKE_PATH_SEPARATOR"
+	bakeEnvFilePath      = "BUILDX_BAKE_FILE"
+)
+
 type bakeOptions struct {
 	files     []string
 	overrides []string
@@ -62,7 +67,7 @@ type bakeOptions struct {
 	listVars    bool
 }
 
-func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in bakeOptions, cFlags commonFlags) (err error) {
+func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in bakeOptions, cFlags commonFlags, filesFromEnv bool) (err error) {
 	mp := dockerCli.MeterProvider()
 
 	ctx, end, err := tracing.TraceCurrentCommand(ctx, append([]string{"bake"}, targets...),
@@ -186,7 +191,7 @@ func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in ba
 		return err
 	}
 
-	files, inp, err := readBakeFiles(ctx, nodes, url, in.files, dockerCli.In(), printer)
+	files, inp, err := readBakeFiles(ctx, nodes, url, in.files, dockerCli.In(), printer, filesFromEnv)
 	if err != nil {
 		return err
 	}
@@ -458,6 +463,15 @@ func bakeCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 		Aliases: []string{"f"},
 		Short:   "Build from a file",
 		RunE: func(cmd *cobra.Command, args []string) error {
+			filesFromEnv := false
+			if len(options.files) == 0 {
+				envFiles, err := bakeEnvFiles(os.LookupEnv)
+				if err != nil {
+					return err
+				}
+				options.files = envFiles
+				filesFromEnv = true
+			}
 			// reset to nil to avoid override is unset
 			if !cmd.Flags().Lookup("no-cache").Changed {
 				cFlags.noCache = nil
@@ -475,7 +489,7 @@ func bakeCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 			options.builder = rootOpts.builder
 			options.metadataFile = cFlags.metadataFile
 			// Other common flags (noCache, pull and progress) are processed in runBake function.
-			return runBake(cmd.Context(), dockerCli, args, options, cFlags)
+			return runBake(cmd.Context(), dockerCli, args, options, cFlags, filesFromEnv)
 		},
 		ValidArgsFunction: completion.BakeTargets(options.files),
 	}
@@ -510,6 +524,37 @@ func bakeCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 	return cmd
 }
 
+func bakeEnvFiles(lookup func(string string) (string, bool)) ([]string, error) {
+	sep, _ := lookup(bakeEnvFileSeparator)
+	if sep == "" {
+		sep = string(os.PathListSeparator)
+	}
+	f, ok := lookup(bakeEnvFilePath)
+	if ok {
+		return cleanPaths(strings.Split(f, sep))
+	}
+	return []string{}, nil
+}
+
+func cleanPaths(p []string) ([]string, error) {
+	var paths []string
+	for _, f := range p {
+		f = strings.TrimSpace(f)
+		if f == "" {
+			continue
+		}
+		if f == "-" {
+			paths = append(paths, f)
+			continue
+		}
+		if _, err := os.Stat(f); err != nil {
+			return nil, err
+		}
+		paths = append(paths, f)
+	}
+	return paths, nil
+}
+
 func saveLocalStateGroup(dockerCli command.Cli, in bakeOptions, targets []string, bo map[string]build.Options) error {
 	l, err := localstate.New(confutil.NewConfig(dockerCli))
 	if err != nil {
@@ -559,7 +604,7 @@ func bakeArgs(args []string) (url, cmdContext string, targets []string) {
 	return url, cmdContext, targets
 }
 
-func readBakeFiles(ctx context.Context, nodes []builder.Node, url string, names []string, stdin io.Reader, pw progress.Writer) (files []bake.File, inp *bake.Input, err error) {
+func readBakeFiles(ctx context.Context, nodes []builder.Node, url string, names []string, stdin io.Reader, pw progress.Writer, filesFromEnv bool) (files []bake.File, inp *bake.Input, err error) {
 	var lnames []string // local
 	var rnames []string // remote
 	var anames []string // both
@@ -584,7 +629,11 @@ func readBakeFiles(ctx context.Context, nodes []builder.Node, url string, names
 
 	if len(lnames) > 0 || url == "" {
 		var lfiles []bake.File
-		progress.Wrap("[internal] load local bake definitions", pw.Write, func(sub progress.SubLogger) error {
+		where := ""
+		if filesFromEnv {
+			where = " from " + bakeEnvFilePath + " env"
+		}
+		progress.Wrap("[internal] load local bake definitions"+where, pw.Write, func(sub progress.SubLogger) error {
 			if url != "" {
 				lfiles, err = bake.ReadLocalFiles(lnames, stdin, sub)
 			} else {