Ensure working JVM before enabling Jib actions to avoid hangs

integration/build_test.go

@@ -28,6 +28,7 @@ import (
 	"github.com/sirupsen/logrus"
 
 	"github.com/GoogleContainerTools/skaffold/integration/skaffold"
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/build/jib"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/docker"
 	kubectx "github.com/GoogleContainerTools/skaffold/pkg/skaffold/kubernetes/context"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/runner/runcontext"
@@ -112,6 +113,9 @@ func TestBuild(t *testing.T) {
 // TestExpectedBuildFailures verifies that `skaffold build` fails in expected ways
 func TestExpectedBuildFailures(t *testing.T) {
 	MarkIntegrationTest(t, CanRunWithoutGcp)
+	if !jib.JVMFound() {
+		t.Fatal("test requires Java VM")
+	}
 
 	tests := []struct {
 		description string

pkg/skaffold/build/gcb/jib_test.go

@@ -17,6 +17,7 @@ limitations under the License.
 package gcb
 
 import (
+	"os"
 	"path/filepath"
 	"testing"
 
@@ -27,6 +28,12 @@ import (
 	"github.com/GoogleContainerTools/skaffold/testutil"
 )
 
+func TestMain(m *testing.M) {
+	// these tests don't actually require a JVM
+	jib.JVMFound = func() bool { return true }
+	os.Exit(m.Run())
+}
+
 func TestJibMavenBuildSpec(t *testing.T) {
 	tests := []struct {
 		description  string

pkg/skaffold/build/jib/init.go

@@ -85,6 +85,10 @@ type jibJSON struct {
 
 // validate checks if a file is a valid Jib configuration. Returns the list of Config objects corresponding to each Jib project built by the file, or nil if Jib is not configured.
 func validate(path string, enableGradleAnalysis bool) []ArtifactConfig {
+	if !JVMFound() {
+		logrus.Debugf("Skipping Jib for init for %q: no functioning Java VM", path)
+		return nil
+	}
 	// Determine whether maven or gradle
 	var builderType PluginType
 	var executable, wrapper, taskName, searchString, consoleFlag string

pkg/skaffold/build/jib/jib.go

@@ -117,6 +117,10 @@ func GetDependencies(ctx context.Context, workspace string, artifact *latest_v1.
 
 // DeterminePluginType tries to determine the Jib plugin type for the given artifact.
 func DeterminePluginType(workspace string, artifact *latest_v1.JibArtifact) (PluginType, error) {
+	if !JVMFound() {
+		return "", errors.New("no working JVM available")
+	}
+
 	// check if explicitly specified
 	if artifact != nil {
 		if t := PluginType(artifact.Type); t.IsKnown() {

pkg/skaffold/build/jib/jvm.go

@@ -0,0 +1,60 @@
+/*
+Copyright 2021 The Skaffold Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package jib
+
+import (
+	"os/exec"
+	"sync"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/util"
+)
+
+var (
+	// JVMFound is replaceable for testing
+	JVMFound = jvmFound
+
+	// JVMFound() returns true if a Java VM was found and works.
+	resolveJVMOnce sync.Once
+	jvmPresent     bool
+)
+
+// jvmFound returns true if a Java VM was found and works.
+func jvmFound() bool {
+	// Check on demand: performing the check in an init() causes the
+	// check to be run even when no jib functionality was used.
+	resolveJVMOnce.Do(func() {
+		jvmPresent = resolveJVM()
+	})
+	return jvmPresent
+}
+
+// resolveJVM returns true if a Java VM was found and works.  It is intended for
+// `skaffold init` on macOS where calling out to the Maven Wrapper script (mvnw) can
+// hang if there is no installed Java VM found.
+func resolveJVM() bool {
+	// Note that just checking for the existence of `java` is insufficient
+	// as macOS ships with /usr/bin/java that tries to hand off to a JVM
+	// installed in /Library/Java/JavaVirtualMachines
+	cmd := exec.Command("java", "-version")
+	err := util.RunCmd(cmd)
+	if err != nil {
+		logrus.Warnf("Skipping Jib: no JVM: %v failed: %v", cmd.Args, err)
+	}
+	return err == nil
+}

pkg/skaffold/build/jib/jvm_test.go

@@ -0,0 +1,51 @@
+/*
+Copyright 2021 The Skaffold Authors
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package jib
+
+import (
+	"errors"
+	"os"
+	"testing"
+
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/util"
+	"github.com/GoogleContainerTools/skaffold/testutil"
+)
+
+func TestMain(m *testing.M) {
+	// these tests don't actually require a JVM
+	JVMFound = func() bool { return true }
+	os.Exit(m.Run())
+}
+
+func TestResolveJVM(t *testing.T) {
+	tests := []struct {
+		name     string
+		cmd      *testutil.FakeCmd
+		expected bool
+	}{
+		{name: "found", cmd: testutil.CmdRun("java -version"), expected: true},
+		{name: "not found", cmd: testutil.CmdRunErr("java -version", errors.New("not found")), expected: false},
+	}
+	for _, test := range tests {
+		testutil.Run(t, test.name, func(t *testutil.T) {
+			t.Override(&util.DefaultExecCommand, test.cmd)
+
+			result := resolveJVM()
+			t.CheckDeepEqual(test.expected, result)
+		})
+	}
+}