controller: only capture the result when invoked through a controller

This ensures that the code used to capture and evaluated a result is
only executed when built through the controller. Otherwise, no build
result should be recorded.

This ensures that new code added to capture and store the build result
for debugging isn't used when BUILDX_EXPERIMENTAL is not set.

Signed-off-by: Justin Chadwell <me@jedevc.com>

commands/build.go

@@ -211,7 +211,7 @@ func runBuild(dockerCli command.Cli, in buildOptions) error {
 			return errors.Wrap(err, "removing image ID file")
 		}
 	}
-	resp, _, err := cbuild.RunBuild(ctx, dockerCli, opts, os.Stdin, progress, nil)
+	resp, _, err := cbuild.RunBuild(ctx, dockerCli, opts, os.Stdin, progress, nil, false)
 	if err != nil {
 		return err
 	}

controller/build/build.go

@@ -46,7 +46,7 @@ const defaultTargetName = "default"
 // NOTE: When an error happens during the build and this function acquires the debuggable *build.ResultContext,
 // this function returns it in addition to the error (i.e. it does "return nil, res, err"). The caller can
 // inspect the result and debug the cause of that error.
-func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.BuildOptions, inStream io.Reader, progressMode string, statusChan chan *client.SolveStatus) (*client.SolveResponse, *build.ResultContext, error) {
+func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.BuildOptions, inStream io.Reader, progressMode string, statusChan chan *client.SolveStatus, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
 	if in.NoCache && len(in.NoCacheFilter) > 0 {
 		return nil, nil, errors.Errorf("--no-cache and --no-cache-filter cannot currently be used together")
 	}
@@ -179,7 +179,7 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.Build
 		return nil, nil, err
 	}
 
-	resp, res, err := buildTargets(ctx, dockerCli, b.NodeGroup, nodes, map[string]build.Options{defaultTargetName: opts}, progressMode, in.MetadataFile, statusChan)
+	resp, res, err := buildTargets(ctx, dockerCli, b.NodeGroup, nodes, map[string]build.Options{defaultTargetName: opts}, progressMode, in.MetadataFile, statusChan, generateResult)
 	err = wrapBuildError(err, false)
 	if err != nil {
 		// NOTE: buildTargets can return *build.ResultContext even on error.
@@ -193,7 +193,7 @@ func RunBuild(ctx context.Context, dockerCli command.Cli, in controllerapi.Build
 // NOTE: When an error happens during the build and this function acquires the debuggable *build.ResultContext,
 // this function returns it in addition to the error (i.e. it does "return nil, res, err"). The caller can
 // inspect the result and debug the cause of that error.
-func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGroup, nodes []builder.Node, opts map[string]build.Options, progressMode string, metadataFile string, statusChan chan *client.SolveStatus) (*client.SolveResponse, *build.ResultContext, error) {
+func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGroup, nodes []builder.Node, opts map[string]build.Options, progressMode string, metadataFile string, statusChan chan *client.SolveStatus, generateResult bool) (*client.SolveResponse, *build.ResultContext, error) {
 	ctx2, cancel := context.WithCancel(context.TODO())
 	defer cancel()
 
@@ -206,15 +206,20 @@ func buildTargets(ctx context.Context, dockerCli command.Cli, ng *store.NodeGrou
 	}
 
 	var res *build.ResultContext
-	var mu sync.Mutex
-	var idx int
-	resp, err := build.BuildWithResultHandler(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress.Tee(printer, statusChan), func(driverIndex int, gotRes *build.ResultContext) {
-		mu.Lock()
-		defer mu.Unlock()
-		if res == nil || driverIndex < idx {
-			idx, res = driverIndex, gotRes
-		}
-	})
+	var resp map[string]*client.SolveResponse
+	if generateResult {
+		var mu sync.Mutex
+		var idx int
+		resp, err = build.BuildWithResultHandler(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress.Tee(printer, statusChan), func(driverIndex int, gotRes *build.ResultContext) {
+			mu.Lock()
+			defer mu.Unlock()
+			if res == nil || driverIndex < idx {
+				idx, res = driverIndex, gotRes
+			}
+		})
+	} else {
+		resp, err = build.Build(ctx, nodes, opts, dockerutil.NewClient(dockerCli), confutil.ConfigDir(dockerCli), progress.Tee(printer, statusChan))
+	}
 	err1 := printer.Wait()
 	if err == nil {
 		err = err1

controller/local/controller.go

@@ -48,7 +48,7 @@ func (b *localController) Build(ctx context.Context, options controllerapi.Build
 	}
 	defer b.buildOnGoing.Store(false)
 
-	resp, res, buildErr := cbuild.RunBuild(ctx, b.dockerCli, options, in, progressMode, nil)
+	resp, res, buildErr := cbuild.RunBuild(ctx, b.dockerCli, options, in, progressMode, nil, true)
 	// NOTE: RunBuild can return *build.ResultContext even on error.
 	if res != nil {
 		b.buildConfig = buildConfig{

controller/remote/controller.go

@@ -143,7 +143,7 @@ func serveCmd(dockerCli command.Cli) *cobra.Command {
 
 			// prepare server
 			b := NewServer(func(ctx context.Context, options *controllerapi.BuildOptions, stdin io.Reader, statusChan chan *client.SolveStatus) (*client.SolveResponse, *build.ResultContext, error) {
-				return cbuild.RunBuild(ctx, dockerCli, *options, stdin, "quiet", statusChan)
+				return cbuild.RunBuild(ctx, dockerCli, *options, stdin, "quiet", statusChan, true)
 			})
 			defer b.Close()