Merge pull request #199 from thaJeztah/18.09_backport_fix_panic_on_empty_dockerfile

[18.09 backport] fix panic on empty dockerfile

builder/remotecontext/detect.go

@@ -12,6 +12,7 @@ import (
 	"github.com/docker/docker/api/types/backend"
 	"github.com/docker/docker/builder"
 	"github.com/docker/docker/builder/dockerignore"
+	"github.com/docker/docker/errdefs"
 	"github.com/docker/docker/pkg/fileutils"
 	"github.com/docker/docker/pkg/urlutil"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
@@ -34,8 +35,9 @@ func Detect(config backend.BuildConfig) (remote builder.Source, dockerfile *pars
 	case remoteURL == ClientSessionRemote:
 		res, err := parser.Parse(config.Source)
 		if err != nil {
-			return nil, nil, err
+			return nil, nil, errdefs.InvalidParameter(err)
 		}
+
 		return nil, res, nil
 	case urlutil.IsGitURL(remoteURL):
 		remote, dockerfile, err = newGitRemote(remoteURL, dockerfilePath)
@@ -106,7 +108,7 @@ func newURLRemote(url string, dockerfilePath string, progressReader func(in io.R
 	switch contentType {
 	case mimeTypes.TextPlain:
 		res, err := parser.Parse(progressReader(content))
-		return nil, res, err
+		return nil, res, errdefs.InvalidParameter(err)
 	default:
 		source, err := FromArchive(progressReader(content))
 		if err != nil {
@@ -146,11 +148,17 @@ func readAndParseDockerfile(name string, rc io.Reader) (*parser.Result, error) {
 	br := bufio.NewReader(rc)
 	if _, err := br.Peek(1); err != nil {
 		if err == io.EOF {
-			return nil, errors.Errorf("the Dockerfile (%s) cannot be empty", name)
+			return nil, errdefs.InvalidParameter(errors.Errorf("the Dockerfile (%s) cannot be empty", name))
 		}
 		return nil, errors.Wrap(err, "unexpected error reading Dockerfile")
 	}
-	return parser.Parse(br)
+
+	dockerfile, err := parser.Parse(br)
+	if err != nil {
+		return nil, errdefs.InvalidParameter(errors.Wrapf(err, "failed to parse %s", name))
+	}
+
+	return dockerfile, nil
 }
 
 func openAt(remote builder.Source, path string) (driver.File, error) {

integration/build/build_test.go

@@ -474,6 +474,61 @@ RUN for g in $(seq 0 8); do dd if=/dev/urandom of=rnd bs=1K count=1 seek=$((1024
 	assert.Check(t, is.Contains(out.String(), "Successfully built"))
 }
 
+func TestBuildWithEmptyDockerfile(t *testing.T) {
+	ctx := context.TODO()
+	defer setupTest(t)()
+
+	tests := []struct {
+		name        string
+		dockerfile  string
+		expectedErr string
+	}{
+		{
+			name:        "empty-dockerfile",
+			dockerfile:  "",
+			expectedErr: "cannot be empty",
+		},
+		{
+			name: "empty-lines-dockerfile",
+			dockerfile: `
+			
+			
+			
+			`,
+			expectedErr: "file with no instructions",
+		},
+		{
+			name:        "comment-only-dockerfile",
+			dockerfile:  `# this is a comment`,
+			expectedErr: "file with no instructions",
+		},
+	}
+
+	apiclient := testEnv.APIClient()
+
+	for _, tc := range tests {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			buf := bytes.NewBuffer(nil)
+			w := tar.NewWriter(buf)
+			writeTarRecord(t, w, "Dockerfile", tc.dockerfile)
+			err := w.Close()
+			assert.NilError(t, err)
+
+			_, err = apiclient.ImageBuild(ctx,
+				buf,
+				types.ImageBuildOptions{
+					Remove:      true,
+					ForceRemove: true,
+				})
+
+			assert.Check(t, is.Contains(err.Error(), tc.expectedErr))
+		})
+	}
+}
+
 func writeTarRecord(t *testing.T, w *tar.Writer, fn, contents string) {
 	err := w.WriteHeader(&tar.Header{
 		Name:     fn,

vendor.conf

@@ -26,7 +26,7 @@ github.com/imdario/mergo v0.3.6
 golang.org/x/sync 1d60e4601c6fd243af51cc01ddf169918a5407ca
 
 # buildkit
-github.com/moby/buildkit ed4da8b4a9661f278ae8433056ca37d0727c408b # docker-18.09 branch
+github.com/moby/buildkit 05766c5c21a1e528eeb1c3522b2f05493fe9ac47 # docker-18.09 branch
 github.com/tonistiigi/fsutil 2862f6bc5ac9b97124e552a5c108230b38a1b0ca
 github.com/grpc-ecosystem/grpc-opentracing 8e809c8a86450a29b90dcc9efbf062d0fe6d9746
 github.com/opentracing/opentracing-go 1361b9cd60be79c4c3a7fa9841b3c132e40066a7

vendor/github.com/moby/buildkit/frontend/dockerfile/parser/parser.go

@@ -275,6 +275,11 @@ func Parse(rwc io.Reader) (*Result, error) {
 	if len(warnings) > 0 {
 		warnings = append(warnings, "[WARNING]: Empty continuation lines will become errors in a future release.")
 	}
+
+	if root.StartLine < 0 {
+		return nil, errors.New("file with no instructions.")
+	}
+
 	return &Result{
 		AST:         root,
 		Warnings:    warnings,