add contextDir to tar on remote

podman build fails on remote build when using a relative context directory.
This is because the context dir was not being added to the tar, so when remote
the compat build function would not be able to stat the contextDir.

resolves #13293

Signed-off-by: cdoern <cbdoer23@g.holycross.edu>

pkg/bindings/images/build.go

@@ -241,7 +241,9 @@ func Build(ctx context.Context, containerFiles []string, options entities.BuildO
 			params.Add("platform", platform)
 		}
 	}
-	if contextDir, err := filepath.EvalSymlinks(options.ContextDirectory); err == nil {
+	var err error
+	var contextDir string
+	if contextDir, err = filepath.EvalSymlinks(options.ContextDirectory); err == nil {
 		options.ContextDirectory = contextDir
 	}
 
@@ -301,7 +303,6 @@ func Build(ctx context.Context, containerFiles []string, options entities.BuildO
 
 	var (
 		headers http.Header
-		err     error
 	)
 	if options.SystemContext != nil && options.SystemContext.DockerAuthConfig != nil {
 		headers, err = auth.MakeXRegistryAuthHeader(options.SystemContext, options.SystemContext.DockerAuthConfig.Username, options.SystemContext.DockerAuthConfig.Password)
@@ -325,7 +326,7 @@ func Build(ctx context.Context, containerFiles []string, options entities.BuildO
 		}
 	}
 
-	contextDir, err := filepath.Abs(options.ContextDirectory)
+	contextDir, err = filepath.Abs(options.ContextDirectory)
 	if err != nil {
 		logrus.Errorf("Cannot find absolute path of %v: %v", options.ContextDirectory, err)
 		return nil, err
@@ -556,16 +557,27 @@ func nTar(excludes []string, sources ...string) (io.ReadCloser, error) {
 				merr = multierror.Append(merr, err)
 				return
 			}
-
 			err = filepath.Walk(s, func(path string, info os.FileInfo, err error) error {
 				if err != nil {
 					return err
 				}
 
-				if path == s {
+				// check if what we are given is an empty dir, if so then continue w/ it. Else return.
-					return nil // skip root dir
+				// if we are given a file or a symlink, we do not want to exclude it.
+				if info.IsDir() && s == path {
+					var p *os.File
+					p, err = os.Open(path)
+					if err != nil {
+						return err
+					}
+					defer p.Close()
+					_, err = p.Readdir(1)
+					if err != io.EOF {
+						return nil // non empty root dir, need to return
+					} else if err != nil {
+						logrus.Errorf("Error while reading directory %v: %v", path, err)
+					}
 				}
-
 				name := filepath.ToSlash(strings.TrimPrefix(path, s+string(filepath.Separator)))
 
 				excluded, err := pm.Matches(name) // nolint:staticcheck

test/e2e/build_test.go

@@ -734,10 +734,11 @@ RUN ls /dev/test1`, ALPINE)
 		err = os.Mkdir("relative", 0755)
 		Expect(err).To(BeNil())
 		containerFilePath := filepath.Join("relative", "Containerfile")
-		fmt.Println(containerFilePath)
+		err = os.Mkdir("relative/build-root", 0755)
+		Expect(err).To(BeNil())
 		err = ioutil.WriteFile(containerFilePath, []byte(containerFile), 0755)
 		Expect(err).To(BeNil())
-		build := podmanTest.Podman([]string{"build", "-f", "./relative/Containerfile"})
+		build := podmanTest.Podman([]string{"build", "-f", "./relative/Containerfile", "./relative/build-root"})
 		build.WaitWithDefaultTimeout()
 		Expect(build).To(Exit(0))
 		err = os.RemoveAll("relative")