Add support for building Maven multimodule projects

pkg/skaffold/build/local/jib_maven.go

@@ -19,7 +19,6 @@ package local
 import (
 	"context"
 	"io"
-	"strings"
 
 	"fmt"
 
@@ -99,8 +98,7 @@ func verifyJibPackageGoal(ctx context.Context, requiredGoal string, workspace st
 	if err != nil {
 		return errors.Wrap(err, "could not obtain jib package goals")
 	}
-	// need to trim last newline
-	goals := strings.Split(strings.TrimSpace(string(stdout)), "\n")
+	goals := util.NonEmptyLines(stdout)
 	logrus.Debugf("jib bound package goals for %s %s: %v (%d)", workspace, a.Module, goals, len(goals))
 	if len(goals) != 1 {
 		return errors.New("skaffold requires a single jib goal bound to 'package'")

pkg/skaffold/jib/jib.go

@@ -19,7 +19,6 @@ package jib
 import (
 	"os/exec"
 	"sort"
-	"strings"
 
 	"os"
 
@@ -36,7 +35,7 @@ func getDependencies(cmd *exec.Cmd) ([]string, error) {
 	}
 
 	// Parses stdout for the dependencies, one per line
-	lines := strings.Split(string(stdout), "\n")
+	lines := util.NonEmptyLines(stdout)
 
 	var deps []string
 	for _, dep := range lines {

pkg/skaffold/util/util.go

@@ -17,6 +17,8 @@ limitations under the License.
 package util
 
 import (
+	"bufio"
+	"bytes"
 	"crypto/rand"
 	"fmt"
 	"io/ioutil"
@@ -227,3 +229,15 @@ func AbsFile(workspace string, filename string) (string, error) {
 	}
 	return filepath.Abs(file)
 }
+
+// NonEmptyLines scans the provided input and returns the non-empty strings found as an array
+func NonEmptyLines(input []byte) []string {
+	var result = []string{}
+	scanner := bufio.NewScanner(bytes.NewReader(input))
+	for scanner.Scan() {
+		if line := scanner.Text(); len(line) > 0 {
+			result = append(result, line)
+		}
+	}
+	return result
+}

pkg/skaffold/util/util_test.go

@@ -193,3 +193,23 @@ func TestAbsFile(t *testing.T) {
 	_, err = AbsFile(tmpDir.Root(), "does-not-exist")
 	testutil.CheckError(t, true, err)
 }
+
+func TestNonEmptyLines(t *testing.T) {
+	var testCases = []struct {
+		in  string
+		out []string
+	}{
+		{"", []string{}},
+		{"a\n", []string{"a"}},
+		{"a\r\n", []string{"a"}},
+		{"a\r\nb", []string{"a", "b"}},
+		{"a\r\nb\n\n", []string{"a", "b"}},
+		{"\na\r\n\n\n", []string{"a"}},
+	}
+	for _, tt := range testCases {
+		t.Run(tt.in, func(t *testing.T) {
+			result := NonEmptyLines([]byte(tt.in))
+			testutil.CheckDeepEqual(t, tt.out, result)
+		})
+	}
+}