builder: prevent Dockerfile to leave build context

Signed-off-by: Tibor Vass <teabee89@gmail.com>
This commit is contained in:
Tibor Vass 2015-02-02 16:17:12 -05:00 committed by Arnaud Porterie
parent 198ff76de5
commit 73d5baf585
4 changed files with 132 additions and 35 deletions

View File

@ -39,6 +39,7 @@ import (
"github.com/docker/docker/pkg/parsers/filters"
"github.com/docker/docker/pkg/promise"
"github.com/docker/docker/pkg/signal"
"github.com/docker/docker/pkg/symlink"
"github.com/docker/docker/pkg/term"
"github.com/docker/docker/pkg/timeutils"
"github.com/docker/docker/pkg/units"
@ -147,36 +148,36 @@ func (cli *DockerCli) CmdBuild(args ...string) error {
return err
}
var filename string // path to Dockerfile
var origDockerfile string // used for error msg
filename := *dockerfileName // path to Dockerfile
if *dockerfileName == "" {
// No -f/--file was specified so use the default
origDockerfile = api.DefaultDockerfileName
*dockerfileName = origDockerfile
*dockerfileName = api.DefaultDockerfileName
filename = path.Join(absRoot, *dockerfileName)
} else {
origDockerfile = *dockerfileName
if filename, err = filepath.Abs(*dockerfileName); err != nil {
return err
}
// Verify that 'filename' is within the build context
if !strings.HasSuffix(absRoot, string(os.PathSeparator)) {
absRoot += string(os.PathSeparator)
}
if !strings.HasPrefix(filename, absRoot) {
return fmt.Errorf("The Dockerfile (%s) must be within the build context (%s)", *dockerfileName, root)
}
// Now reset the dockerfileName to be relative to the build context
*dockerfileName = filename[len(absRoot):]
}
if _, err = os.Stat(filename); os.IsNotExist(err) {
return fmt.Errorf("Can not locate Dockerfile: %s", origDockerfile)
origDockerfile := *dockerfileName // used for error msg
if filename, err = filepath.Abs(filename); err != nil {
return err
}
var includes []string = []string{"."}
// Verify that 'filename' is within the build context
filename, err = symlink.FollowSymlinkInScope(filename, absRoot)
if err != nil {
return fmt.Errorf("The Dockerfile (%s) must be within the build context (%s)", origDockerfile, root)
}
// Now reset the dockerfileName to be relative to the build context
*dockerfileName, err = filepath.Rel(filename, absRoot)
if err != nil {
return err
}
if _, err = os.Lstat(filename); os.IsNotExist(err) {
return fmt.Errorf("Cannot locate Dockerfile: %s", origDockerfile)
}
var includes = []string{"."}
excludes, err := utils.ReadDockerIgnore(path.Join(root, ".dockerignore"))
if err != nil {

View File

@ -32,6 +32,7 @@ import (
"github.com/docker/docker/daemon"
"github.com/docker/docker/engine"
"github.com/docker/docker/pkg/fileutils"
"github.com/docker/docker/pkg/symlink"
"github.com/docker/docker/pkg/tarsum"
"github.com/docker/docker/registry"
"github.com/docker/docker/runconfig"
@ -170,16 +171,12 @@ func (b *Builder) Run(context io.Reader) (string, error) {
// Reads a Dockerfile from the current context. It assumes that the
// 'filename' is a relative path from the root of the context
func (b *Builder) readDockerfile(origFile string) error {
filename := filepath.Join(b.contextPath, origFile)
tmpDockerPath := filepath.Dir(filename) + string(os.PathSeparator)
tmpContextPath := filepath.Clean(b.contextPath) + string(os.PathSeparator)
if !strings.HasPrefix(tmpDockerPath, tmpContextPath) {
return fmt.Errorf("Dockerfile (%s) must be within the build context", origFile)
filename, err := symlink.FollowSymlinkInScope(filepath.Join(b.contextPath, origFile), b.contextPath)
if err != nil {
return fmt.Errorf("The Dockerfile (%s) must be within the build context", origFile)
}
fi, err := os.Stat(filename)
fi, err := os.Lstat(filename)
if os.IsNotExist(err) {
return fmt.Errorf("Cannot locate specified Dockerfile: %s", origFile)
}

View File

@ -307,13 +307,14 @@ func TestBuildApiDockerfilePath(t *testing.T) {
tw := tar.NewWriter(buffer)
defer tw.Close()
dockerfile := []byte("FROM busybox")
if err := tw.WriteHeader(&tar.Header{
Name: "Dockerfile",
Size: 11,
Size: int64(len(dockerfile)),
}); err != nil {
t.Fatalf("failed to write tar file header: %v", err)
}
if _, err := tw.Write([]byte("FROM ubuntu")); err != nil {
if _, err := tw.Write(dockerfile); err != nil {
t.Fatalf("failed to write tar file content: %v", err)
}
if err := tw.Close(); err != nil {
@ -322,12 +323,46 @@ func TestBuildApiDockerfilePath(t *testing.T) {
out, err := sockRequestRaw("POST", "/build?dockerfile=../Dockerfile", buffer, "application/x-tar")
if err == nil {
t.Fatalf("Build was supposed to fail")
t.Fatalf("Build was supposed to fail: %s", out)
}
if !strings.Contains(string(out), "must be within the build context") {
t.Fatalf("Didn't complain about leaving build context")
t.Fatalf("Didn't complain about leaving build context: %s", out)
}
logDone("container REST API - check build w/bad Dockerfile path")
}
func TestBuildApiDockerfileSymlink(t *testing.T) {
// Test to make sure we stop people from trying to leave the
// build context when specifying a symlink as the path to the dockerfile
buffer := new(bytes.Buffer)
tw := tar.NewWriter(buffer)
defer tw.Close()
if err := tw.WriteHeader(&tar.Header{
Name: "Dockerfile",
Typeflag: tar.TypeSymlink,
Linkname: "/etc/passwd",
}); err != nil {
t.Fatalf("failed to write tar file header: %v", err)
}
if err := tw.Close(); err != nil {
t.Fatalf("failed to close tar archive: %v", err)
}
out, err := sockRequestRaw("POST", "/build", buffer, "application/x-tar")
if err == nil {
t.Fatalf("Build was supposed to fail: %s", out)
}
// The reason the error is "Cannot locate specified Dockerfile" is because
// in the builder, the symlink is resolved within the context, therefore
// Dockerfile -> /etc/passwd becomes etc/passwd from the context which is
// a nonexistent file.
if !strings.Contains(string(out), "Cannot locate specified Dockerfile: Dockerfile") {
t.Fatalf("Didn't complain about leaving build context: %s", out)
}
logDone("container REST API - check build w/bad Dockerfile symlink path")
}

View File

@ -4630,3 +4630,67 @@ func TestBuildFromOfficialNames(t *testing.T) {
}
logDone("build - from official names")
}
func TestBuildDockerfileOutsideContext(t *testing.T) {
name := "testbuilddockerfileoutsidecontext"
tmpdir, err := ioutil.TempDir("", name)
if err != nil {
t.Fatal(err)
}
defer os.RemoveAll(tmpdir)
ctx := filepath.Join(tmpdir, "context")
if err := os.MkdirAll(ctx, 0755); err != nil {
t.Fatal(err)
}
if err := ioutil.WriteFile(filepath.Join(ctx, "Dockerfile"), []byte("FROM busybox"), 0644); err != nil {
t.Fatal(err)
}
wd, err := os.Getwd()
if err != nil {
t.Fatal(err)
}
defer os.Chdir(wd)
if err := os.Chdir(ctx); err != nil {
t.Fatal(err)
}
if err := ioutil.WriteFile(filepath.Join(tmpdir, "outsideDockerfile"), []byte("FROM busbox"), 0644); err != nil {
t.Fatal(err)
}
if err := os.Symlink("../outsideDockerfile", filepath.Join(ctx, "dockerfile1")); err != nil {
t.Fatal(err)
}
if err := os.Symlink(filepath.Join(tmpdir, "outsideDockerfile"), filepath.Join(ctx, "dockerfile2")); err != nil {
t.Fatal(err)
}
if err := os.Link("../outsideDockerfile", filepath.Join(ctx, "dockerfile3")); err != nil {
t.Fatal(err)
}
if err := os.Link(filepath.Join(tmpdir, "outsideDockerfile"), filepath.Join(ctx, "dockerfile4")); err != nil {
t.Fatal(err)
}
for _, dockerfilePath := range []string{
"../outsideDockerfile",
filepath.Join(ctx, "dockerfile1"),
filepath.Join(ctx, "dockerfile2"),
filepath.Join(ctx, "dockerfile3"),
filepath.Join(ctx, "dockerfile4"),
} {
out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "build", "-t", name, "--no-cache", "-f", dockerfilePath, "."))
if err == nil {
t.Fatalf("Expected error with %s. Out: %s", dockerfilePath, out)
}
deleteImages(name)
}
os.Chdir(tmpdir)
// Path to Dockerfile should be resolved relative to working directory, not relative to context.
// There is a Dockerfile in the context, but since there is no Dockerfile in the current directory, the following should fail
out, _, err := runCommandWithOutput(exec.Command(dockerBinary, "build", "-t", name, "--no-cache", "-f", "Dockerfile", ctx))
if err == nil {
t.Fatalf("Expected error. Out: %s", out)
}
deleteImages(name)
logDone("build - Dockerfile outside context")
}