Merge pull request #3819 from giggsoff/dirty-fix

Append dirty tag with content hash

src/cmd/linuxkit/pkglib/git.go

@@ -3,10 +3,13 @@ package pkglib
 // Thin wrappers around git CLI invocations
 
 import (
+	"bufio"
+	"crypto/sha256"
 	"fmt"
 	"io"
 	"os"
 	"os/exec"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -83,6 +86,32 @@ func (g git) isWorkTree(pkg string) (bool, error) {
 	return false, fmt.Errorf("unexpected output from git rev-parse --is-inside-work-tree: %s", tf)
 }
 
+func (g git) contentHash() (string, error) {
+	hash := sha256.New()
+	out, err := g.commandStdout(nil, "ls-files")
+	if err != nil {
+		return "", err
+	}
+	scanner := bufio.NewScanner(strings.NewReader(strings.TrimSpace(out)))
+	for scanner.Scan() {
+		f, err := os.Open(filepath.Join(g.dir, scanner.Text()))
+		if err != nil {
+			return "", err
+		}
+		if _, err := io.Copy(hash, f); err != nil {
+			_ = f.Close()
+			return "", err
+		}
+		if err = f.Close(); err != nil {
+			return "", err
+		}
+	}
+	if err = scanner.Err(); err != nil {
+		return "", err
+	}
+	return fmt.Sprintf("%x", hash.Sum(nil)), nil
+}
+
 func (g git) treeHash(pkg, commit string) (string, error) {
 	// we have to check if pkg is at the top level of the git tree,
 	// if that's the case we need to use tree hash from the commit itself

src/cmd/linuxkit/pkglib/pkglib.go

@@ -250,7 +250,15 @@ func NewFromCLI(fs *flag.FlagSet, args ...string) ([]Pkg, error) {
 				}
 
 				if dirty {
-					pkgHash += "-dirty"
+					contentHash, err := git.contentHash()
+					if err != nil {
+						return nil, err
+					}
+					if len(contentHash) < 7 {
+						return nil, fmt.Errorf("unexpected hash len: %d", len(contentHash))
+					}
+					// construct <ls-tree>-dirty-<content hash> tag
+					pkgHash += fmt.Sprintf("-dirty-%s", contentHash[0:7])
 				}
 			}
 		}