cmd: fix possible skipped defers for build and bake

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

.golangci.yml

@@ -49,7 +49,6 @@ linters:
         - "assignOp"
         - "appendAssign"
         - "singleCaseSwitch"
-        - "exitAfterDefer" # FIXME
     gosec:
       excludes:
         - G204

cmd/buildx/main.go

@@ -7,6 +7,7 @@ import (
 	"path/filepath"
 
 	"github.com/docker/buildx/commands"
+	"github.com/docker/buildx/util/cobrautil"
 	"github.com/docker/buildx/util/desktop"
 	"github.com/docker/buildx/version"
 	"github.com/docker/cli/cli"
@@ -101,6 +102,13 @@ func main() {
 		os.Exit(sterr.StatusCode)
 	}
 
+	// Check for ExitCodeError, which is used to exit with a specific code
+	// without printing an error message.
+	var exitCodeErr cobrautil.ExitCodeError
+	if errors.As(err, &exitCodeErr) {
+		os.Exit(int(exitCodeErr))
+	}
+
 	for _, s := range solvererrdefs.Sources(err) {
 		s.Print(cmd.Err())
 	}

commands/bake.go

@@ -24,6 +24,7 @@ import (
 	"github.com/docker/buildx/builder"
 	"github.com/docker/buildx/localstate"
 	"github.com/docker/buildx/util/buildflags"
+	"github.com/docker/buildx/util/cobrautil"
 	"github.com/docker/buildx/util/cobrautil/completion"
 	"github.com/docker/buildx/util/confutil"
 	"github.com/docker/buildx/util/desktop"
@@ -448,7 +449,7 @@ func runBake(ctx context.Context, dockerCli command.Cli, targets []string, in ba
 	}
 
 	if exitCode != 0 {
-		os.Exit(exitCode)
+		return cobrautil.ExitCodeError(exitCode)
 	}
 
 	return nil

commands/build.go

@@ -384,10 +384,10 @@ func runBuild(ctx context.Context, dockerCli command.Cli, options buildOptions)
 		}
 	}
 	if opts.CallFunc != nil {
-		if exitcode, err := printResult(dockerCli.Out(), opts.CallFunc, resp.ExporterResponse, options.target, inputs); err != nil {
+		if exitCode, err := printResult(dockerCli.Out(), opts.CallFunc, resp.ExporterResponse, options.target, inputs); err != nil {
 			return err
-		} else if exitcode != 0 {
+		} else if exitCode != 0 {
-			os.Exit(exitcode)
+			return cobrautil.ExitCodeError(exitCode)
 		}
 	}
 	if v, ok := resp.ExporterResponse["frontend.result.inlinemessage"]; ok {

util/cobrautil/error.go

@@ -0,0 +1,15 @@
+package cobrautil
+
+import (
+	"fmt"
+)
+
+type ExitCodeError int
+
+func (e ExitCodeError) Error() string {
+	return fmt.Sprintf("exiting with code %d", int(e))
+}
+
+func (e ExitCodeError) Unwrap() error {
+	return nil
+}