kyaml: initial support for yaml and resource manipulation

kyaml/copyutil/copyutil.go

@@ -0,0 +1,128 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+// The copyutil package contains libraries for copying directories of configuration.
+package copyutil
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"sigs.k8s.io/kustomize/kyaml/sets"
+)
+
+// CopyDir copies a src directory to a dst directory.  CopyDir skips copying the .git directory from the src.
+func CopyDir(src string, dst string) error {
+	return filepath.Walk(src, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		// don't copy the .git dir
+		if path != src {
+			rel := strings.TrimPrefix(path, src)
+			if strings.HasPrefix(rel, string(filepath.Separator)+".git") {
+				return nil
+			}
+		}
+
+		// path is an absolute path, rather than a path relative to src.
+		// e.g. if src is /path/to/package, then path might be /path/to/package/and/sub/dir
+		// we need the path relative to src `and/sub/dir` when we are copying the files to dest.
+		copyTo := strings.TrimPrefix(path, src)
+
+		// make directories that don't exist
+		if info.IsDir() {
+			return os.MkdirAll(filepath.Join(dst, copyTo), info.Mode())
+		}
+
+		// copy file by reading and writing it
+		b, err := ioutil.ReadFile(filepath.Join(src, copyTo))
+		if err != nil {
+			return err
+		}
+		err = ioutil.WriteFile(filepath.Join(dst, copyTo), b, info.Mode())
+		if err != nil {
+			return err
+		}
+
+		return nil
+	})
+}
+
+// Diff returns a list of files that differ between the source and destination.
+//
+// Diff is guaranteed to return a non-empty set if any files differ, but
+// this set is not guaranteed to contain all differing files.
+func Diff(sourceDir, destDir string) (sets.String, error) {
+	// get set of filenames in the package source
+	upstreamFiles := sets.String{}
+	err := filepath.Walk(sourceDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// skip git repo if it exists
+		if strings.Contains(path, ".git") {
+			return nil
+		}
+
+		upstreamFiles.Insert(strings.TrimPrefix(strings.TrimPrefix(path, sourceDir), string(filepath.Separator)))
+		return nil
+	})
+	if err != nil {
+		return sets.String{}, err
+	}
+
+	// get set of filenames in the cloned package
+	localFiles := sets.String{}
+	err = filepath.Walk(destDir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		// skip git repo if it exists
+		if strings.Contains(path, ".git") {
+			return nil
+		}
+
+		localFiles.Insert(strings.TrimPrefix(strings.TrimPrefix(path, destDir), string(filepath.Separator)))
+		return nil
+	})
+	if err != nil {
+		return sets.String{}, err
+	}
+
+	// verify the source and cloned packages have the same set of filenames
+	diff := upstreamFiles.SymmetricDifference(localFiles)
+
+	// verify file contents match
+	for _, f := range upstreamFiles.Intersection(localFiles).List() {
+		fi, err := os.Stat(filepath.Join(destDir, f))
+		if err != nil {
+			return diff, err
+		}
+		if fi.Mode().IsDir() {
+			// already checked that this directory exists in the local files
+			continue
+		}
+
+		// compare upstreamFiles
+		b1, err := ioutil.ReadFile(filepath.Join(destDir, f))
+		if err != nil {
+			return diff, err
+		}
+		b2, err := ioutil.ReadFile(filepath.Join(sourceDir, f))
+		if err != nil {
+			return diff, err
+		}
+		if !bytes.Equal(b1, b2) {
+			diff.Insert(f)
+		}
+	}
+
+	// return the differing files
+	return diff, nil
+}