stage_executor: history should include heredoc summary correctly

imagebuildah/stage_executor.go

@@ -1943,17 +1943,20 @@ func (s *StageExecutor) getCreatedBy(node *parser.Node, addedContentSummary stri
 		if len(node.Original) > 4 {
 			shArg = node.Original[4:]
 		}
-		if buildArgs != "" {
-			return "|" + strconv.Itoa(len(strings.Split(buildArgs, " "))) + " " + buildArgs + " /bin/sh -c " + shArg + appendCheckSum, nil
-		}
-		result := "/bin/sh -c " + shArg
+
+		heredoc := ""
+		result := ""
 		if len(node.Heredocs) > 0 {
 			for _, doc := range node.Heredocs {
 				heredocContent := strings.TrimSpace(doc.Content)
-				result = result + "\n" + heredocContent
+				heredoc = heredoc + "\n" + heredocContent
 			}
 		}
-		return result + appendCheckSum, nil
+		if buildArgs != "" {
+			result = result + "|" + strconv.Itoa(len(strings.Split(buildArgs, " "))) + " " + buildArgs + " "
+		}
+		result = result + "/bin/sh -c " + shArg + heredoc + appendCheckSum
+		return result, nil
 	case "ADD", "COPY":
 		destination := node
 		for destination.Next != nil {

tests/bud.bats

@@ -542,6 +542,44 @@ _EOF
   expect_output --substring "Cache burst add diff"
 }
 
+@test "bud --layers should not hit cache if heredoc is changed - with ARG" {
+  _prefetch alpine
+  local contextdir=${TEST_SCRATCH_DIR}/bud/platform
+  mkdir -p $contextdir
+
+  cat > $contextdir/Dockerfile << _EOF
+FROM alpine
+ARG key=value
+RUN <<EOF
+echo "Cache burst" >> /hello
+echo "Cache burst second line" >> /hello
+EOF
+RUN cat hello
+_EOF
+
+  # on first run since there is no cache so `Cache burst` must be printed
+  run_buildah build $WITH_POLICY_JSON --layers -t source -f $contextdir/Dockerfile
+  expect_output --substring "Cache burst second line"
+
+  # on second run since there is cache so `Cache burst` should not be printed
+  run_buildah build $WITH_POLICY_JSON --layers -t source -f $contextdir/Dockerfile
+  # output should not contain cache burst
+  assert "$output" !~ "Cache burst second line"
+
+  cat > $contextdir/Dockerfile << _EOF
+FROM alpine
+ARG key=value
+RUN <<EOF
+echo "Cache burst add diff" >> /hello
+EOF
+RUN cat hello
+_EOF
+
+  # on third run since we have changed heredoc so `Cache burst` must be printed.
+  run_buildah build $WITH_POLICY_JSON --layers -t source -f $contextdir/Dockerfile
+  expect_output --substring "Cache burst add diff"
+}
+
 @test "bud build with heredoc content" {
   _prefetch alpine
   run_buildah build -t heredoc $WITH_POLICY_JSON -f $BUDFILES/heredoc/Containerfile .