build: use buildkit's gitutil package to detect remote files

BuildKit's gitutil package behaves slightly differently than moby's
urlutil, so we should rely on BuildKit's gitutil when detecting URLs to
avoid cases of accidentally producing invalid build requests that can
confuse users.

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

bake/bake.go

@@ -18,7 +18,6 @@ import (
 	"github.com/docker/buildx/util/buildflags"
 	"github.com/docker/buildx/util/platformutil"
 	"github.com/docker/cli/cli/config"
-	"github.com/docker/docker/builder/remotecontext/urlutil"
 	hcl "github.com/hashicorp/hcl/v2"
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/session/auth/authprovider"
@@ -884,7 +883,7 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 		dockerfilePath = *t.Dockerfile
 	}
 
-	if !isRemoteResource(contextPath) && !path.IsAbs(dockerfilePath) {
+	if !build.IsRemoteURL(contextPath) && !path.IsAbs(dockerfilePath) {
 		dockerfilePath = path.Join(contextPath, dockerfilePath)
 	}
 
@@ -1040,10 +1039,6 @@ func removeDupes(s []string) []string {
 	return s[:i]
 }
 
-func isRemoteResource(str string) bool {
-	return urlutil.IsGitURL(str) || urlutil.IsURL(str)
-}
-
 func parseOutputType(str string) string {
 	csvReader := csv.NewReader(strings.NewReader(str))
 	fields, err := csvReader.Read()

build/build.go

@@ -1278,7 +1278,6 @@ func LoadInputs(ctx context.Context, d driver.Driver, inp Inputs, pw progress.Wr
 				target.LocalDirs["context"] = inp.ContextPath
 			}
 		}
-
 	case isLocalDir(inp.ContextPath):
 		target.LocalDirs["context"] = inp.ContextPath
 		switch inp.DockerfilePath {
@@ -1290,8 +1289,7 @@ func LoadInputs(ctx context.Context, d driver.Driver, inp Inputs, pw progress.Wr
 			dockerfileDir = filepath.Dir(inp.DockerfilePath)
 			dockerfileName = filepath.Base(inp.DockerfilePath)
 		}
-
-	case urlutil.IsGitURL(inp.ContextPath), urlutil.IsURL(inp.ContextPath):
+	case IsRemoteURL(inp.ContextPath):
 		if inp.DockerfilePath == "-" {
 			dockerfileReader = inp.InStream
 		}
@@ -1346,7 +1344,7 @@ func LoadInputs(ctx context.Context, d driver.Driver, inp Inputs, pw progress.Wr
 			continue
 		}
 
-		if urlutil.IsGitURL(v.Path) || urlutil.IsURL(v.Path) || strings.HasPrefix(v.Path, "docker-image://") || strings.HasPrefix(v.Path, "target:") {
+		if IsRemoteURL(v.Path) || strings.HasPrefix(v.Path, "docker-image://") || strings.HasPrefix(v.Path, "target:") {
 			target.FrontendAttrs["context:"+k] = v.Path
 			continue
 		}

build/utils.go

@@ -8,6 +8,8 @@ import (
 	"strings"
 
 	"github.com/docker/cli/opts"
+	"github.com/docker/docker/builder/remotecontext/urlutil"
+	"github.com/moby/buildkit/util/gitutil"
 	"github.com/pkg/errors"
 )
 
@@ -20,6 +22,16 @@ const (
 	mobyHostGatewayName = "host-gateway"
 )
 
+func IsRemoteURL(c string) bool {
+	if urlutil.IsURL(c) {
+		return true
+	}
+	if _, err := gitutil.ParseGitRef(c); err == nil {
+		return true
+	}
+	return false
+}
+
 func isLocalDir(c string) bool {
 	st, err := os.Stat(c)
 	return err == nil && st.IsDir()

commands/build.go

@@ -14,6 +14,7 @@ import (
 	"strings"
 
 	"github.com/containerd/console"
+	"github.com/docker/buildx/build"
 	"github.com/docker/buildx/controller"
 	cbuild "github.com/docker/buildx/controller/build"
 	"github.com/docker/buildx/controller/control"
@@ -29,7 +30,6 @@ import (
 	"github.com/docker/cli/cli"
 	"github.com/docker/cli/cli/command"
 	dockeropts "github.com/docker/cli/opts"
-	"github.com/docker/docker/builder/remotecontext/urlutil"
 	"github.com/docker/docker/pkg/ioutils"
 	"github.com/moby/buildkit/client"
 	"github.com/moby/buildkit/exporter/containerimage/exptypes"
@@ -670,7 +670,7 @@ func dockerUlimitToControllerUlimit(u *dockeropts.UlimitOpt) *controllerapi.Ulim
 // and replaces them to absolute paths.
 func resolvePaths(options *controllerapi.BuildOptions) (_ *controllerapi.BuildOptions, err error) {
 	if options.ContextPath != "" && options.ContextPath != "-" {
-		if !urlutil.IsGitURL(options.ContextPath) && !urlutil.IsURL(options.ContextPath) {
+		if !build.IsRemoteURL(options.ContextPath) {
 			options.ContextPath, err = filepath.Abs(options.ContextPath)
 			if err != nil {
 				return nil, err
@@ -685,7 +685,7 @@ func resolvePaths(options *controllerapi.BuildOptions) (_ *controllerapi.BuildOp
 	}
 	var contexts map[string]string
 	for k, v := range options.NamedContexts {
-		if urlutil.IsGitURL(v) || urlutil.IsURL(v) || strings.HasPrefix(v, "docker-image://") {
+		if build.IsRemoteURL(v) || strings.HasPrefix(v, "docker-image://") {
 			// url prefix, this is a remote path
 		} else if strings.HasPrefix(v, "oci-layout://") {
 			// oci layout prefix, this is a local path