Merge pull request #42197 from thaJeztah/20.10_backport_improve_build_errors

[20.10 backport] builder: produce error when using unsupported Dockerfile option

builder/dockerfile/dispatchers.go

@@ -92,6 +92,9 @@ func dispatchLabel(d dispatchRequest, c *instructions.LabelCommand) error {
 // exist here. If you do not wish to have this automatic handling, use COPY.
 //
 func dispatchAdd(d dispatchRequest, c *instructions.AddCommand) error {
+	if c.Chmod != "" {
+		return errors.New("the --chmod option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled")
+	}
 	downloader := newRemoteSourceDownloader(d.builder.Output, d.builder.Stdout)
 	copier := copierFromDispatchRequest(d, downloader, nil)
 	defer copier.Cleanup()
@@ -111,6 +114,9 @@ func dispatchAdd(d dispatchRequest, c *instructions.AddCommand) error {
 // Same as 'ADD' but without the tar and remote url handling.
 //
 func dispatchCopy(d dispatchRequest, c *instructions.CopyCommand) error {
+	if c.Chmod != "" {
+		return errors.New("the --chmod option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled")
+	}
 	var im *imageMount
 	var err error
 	if c.From != "" {
@@ -346,6 +352,12 @@ func dispatchRun(d dispatchRequest, c *instructions.RunCommand) error {
 	if !system.IsOSSupported(d.state.operatingSystem) {
 		return system.ErrNotSupportedOperatingSystem
 	}
+
+	if len(c.FlagsUsed) > 0 {
+		// classic builder RUN currently does not support any flags, so fail on the first one
+		return errors.Errorf("the --%s option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled", c.FlagsUsed[0])
+	}
+
 	stateRunConfig := d.state.runConfig
 	cmdFromArgs, argsEscaped := resolveCmdLine(c.ShellDependantCmdLine, stateRunConfig, d.state.operatingSystem, c.Name(), c.String())
 	buildArgs := d.state.buildArgs.FilterAllowed(stateRunConfig.Env)

builder/dockerfile/dispatchers_test.go

@@ -3,6 +3,7 @@ package dockerfile // import "github.com/docker/docker/builder/dockerfile"
 import (
 	"bytes"
 	"context"
+	"fmt"
 	"runtime"
 	"strings"
 	"testing"
@@ -570,3 +571,40 @@ func TestRunIgnoresHealthcheck(t *testing.T) {
 	assert.NilError(t, dispatch(sb, run))
 	assert.Check(t, is.DeepEqual(expectedTest, sb.state.runConfig.Healthcheck.Test))
 }
+
+func TestDispatchUnsupportedOptions(t *testing.T) {
+	b := newBuilderWithMockBackend()
+	sb := newDispatchRequest(b, '`', nil, NewBuildArgs(make(map[string]*string)), newStagesBuildResults())
+	sb.state.baseImage = &mockImage{}
+	sb.state.operatingSystem = runtime.GOOS
+
+	t.Run("ADD with chmod", func(t *testing.T) {
+		cmd := &instructions.AddCommand{SourcesAndDest: []string{".", "."}, Chmod: "0655"}
+		err := dispatch(sb, cmd)
+		assert.Error(t, err, "the --chmod option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled")
+	})
+
+	t.Run("COPY with chmod", func(t *testing.T) {
+		cmd := &instructions.CopyCommand{SourcesAndDest: []string{".", "."}, Chmod: "0655"}
+		err := dispatch(sb, cmd)
+		assert.Error(t, err, "the --chmod option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled")
+	})
+
+	t.Run("RUN with unsupported options", func(t *testing.T) {
+		cmd := &instructions.RunCommand{
+			ShellDependantCmdLine: instructions.ShellDependantCmdLine{
+				CmdLine:      strslice.StrSlice{"echo foo"},
+				PrependShell: true,
+			},
+		}
+
+		// classic builder "RUN" currently doesn't support any flags, but testing
+		// both "known" flags and "bogus" flags for completeness, and in case
+		// one or more of these flags will be supported in future
+		for _, f := range []string{"mount", "network", "security", "any-flag"} {
+			cmd.FlagsUsed = []string{f}
+			err := dispatch(sb, cmd)
+			assert.Error(t, err, fmt.Sprintf("the --%s option requires BuildKit. Refer to https://docs.docker.com/go/buildkit/ to learn how to build images with BuildKit enabled", f))
+		}
+	})
+}