Fix symlink path separators (knative#2535) (#967)

When running on Windows the path separators in symlink target is
backslash. This must be fixed up when uploading source code into docker
daemon or into cluster volume.

Signed-off-by: Matej Vašek <[email protected]>

Author: matejvasek

pkg/builders/s2i/builder.go

@@ -295,7 +295,7 @@ func (b *Builder) Build(ctx context.Context, f fn.Function, platforms []fn.Platf
 				}
 			}
 
-			hdr, err := tar.FileInfoHeader(fi, lnk)
+			hdr, err := tar.FileInfoHeader(fi, filepath.ToSlash(lnk))
 			if err != nil {
 				return fmt.Errorf("cannot create tar header: %w", err)
 			}

pkg/pipelines/tekton/pipelines_provider.go

@@ -336,7 +336,7 @@ func sourcesAsTarStream(f fn.Function) *io.PipeReader {
 				}
 			}
 
-			hdr, err := tar.FileInfoHeader(fi, lnk)
+			hdr, err := tar.FileInfoHeader(fi, filepath.ToSlash(lnk))
 			if err != nil {
 				return fmt.Errorf("cannot create a tar header: %w", err)
 			}