Display source of bake definitions when read from environment

While it would make sense to add "from file" to complement "from env,"
 (in the common case of `--file` or using the default), it wouldn't
 provide any real value.

A simpler solution would have been looking for the existence of the
variable at the point where printing happens.  It felt wrong
duplicating the logic.  Executing the same logic (if it was extracted)
wouldn't be as bad, but still not ideal.

A 'correct' solution would be to explicitly track the source of each
definition, which would be clearer and more future-proof.  It didn't
seem like this feature warranted that amount of engineering (with no
known features that might make use of it).

This implementation seemed like a fair compromise; none of the functions
 are exported, and all have only one caller.

I also considered converting prefixing environment values with `env://`
so they could be thought of (and processed like) `cmd://` values.  I
didn't think it would be viewed as a good solution.

Co-authored-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>
Signed-off-by: Roberto Villarreal <rrjjvv@yahoo.com>

Author: rrjjvv

commands/bake.go

@@ -67,7 +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...),
@@ -185,7 +185,7 @@ 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
 	}
@@ -457,12 +457,14 @@ 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 {
@@ -481,7 +483,7 @@ 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),
 	}
@@ -596,7 +598,7 @@ 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
@@ -621,7 +623,11 @@ 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 {

tests/bake.go

@@ -2213,7 +2213,7 @@ target "second" {
 
 		dt, err := cmd.CombinedOutput()
 		require.NoError(t, err, string(dt))
-		require.Contains(t, string(dt), `#1 [internal] load local bake definitions`)
+		require.Contains(t, string(dt), `#1 [internal] load local bake definitions from BUILDX_BAKE_FILE env`)
 		require.Contains(t, string(dt), `#1 reading first.hcl`)
 	})
 
@@ -2230,7 +2230,7 @@ target "second" {
 
 		dt, err := cmd.CombinedOutput()
 		require.NoError(t, err, string(dt))
-		require.Contains(t, string(dt), `#1 [internal] load local bake definitions`)
+		require.Contains(t, string(dt), `#1 [internal] load local bake definitions from BUILDX_BAKE_FILE env`)
 		require.Contains(t, string(dt), `#1 reading first.hcl`)
 		require.NotContains(t, string(dt), "docker-bake.hcl")
 	})
@@ -2249,7 +2249,7 @@ target "second" {
 			withEnv("BUILDX_BAKE_FILE=first.hcl"+string(os.PathListSeparator)+"second.hcl"))
 		dt, err := cmd.CombinedOutput()
 		require.NoError(t, err, string(dt))
-		require.Contains(t, string(dt), `#1 [internal] load local bake definitions`)
+		require.Contains(t, string(dt), `#1 [internal] load local bake definitions from BUILDX_BAKE_FILE env`)
 		require.Contains(t, string(dt), `#1 reading first.hcl`)
 		require.Contains(t, string(dt), `#1 reading second.hcl`)
 	})
@@ -2269,7 +2269,7 @@ target "second" {
 
 		dt, err := cmd.CombinedOutput()
 		require.NoError(t, err, string(dt))
-		require.Contains(t, string(dt), `#1 [internal] load local bake definitions`)
+		require.Contains(t, string(dt), `#1 [internal] load local bake definitions from BUILDX_BAKE_FILE env`)
 		require.Contains(t, string(dt), `#1 reading first.hcl`)
 		require.Contains(t, string(dt), `#1 reading second.hcl`)
 	})
@@ -2294,7 +2294,7 @@ target "second" {
 
 		dt, err := cmd.CombinedOutput()
 		require.NoError(t, err, string(dt))
-		require.Contains(t, string(dt), `#1 [internal] load local bake definitions`)
+		require.Contains(t, string(dt), `#1 [internal] load local bake definitions from BUILDX_BAKE_FILE env`)
 		require.Contains(t, string(dt), `#1 reading first.hcl`)
 		require.Contains(t, string(dt), `#1 reading from stdin`)
 	})