Add a setting for kustomize plugins

This adds an env var-driven configuration for the filesystem path
in which kustomize should expect its plugins (including airshipctl)
to be.  The value defaults to a subfolder off the `.airshipit` folder.

The config is persisted as a singleton rather than a member of
AirshipCTLSettings (or the Config) because
1. the settings object would have had to have been passed around
   a couple dozen additional files/functions,
2. it's reasonable to expect the plugin location to be consistent
   across threads in a multi-threaded, airshipctl-as-library context.

Settings_test.go was moved in to an environment_test package to avoid
a circular import dependency.

Change-Id: Icdd21bd3687ef42492e388af982d7b490af3eff3

pkg/config/constants.go

@@ -51,6 +51,8 @@ const (
 	AirshipDefaultManifestRepoLocation    = "https://opendev.org/airship/" + AirshipDefaultManifestRepo
 	AirshipKubeConfig                     = "kubeconfig"
 	AirshipKubeConfigEnv                  = "AIRSHIP_KUBECONFIG"
+	AirshipPluginPath                     = "kustomize-plugins"
+	AirshipPluginPathEnv                  = "AIRSHIP_KUSTOMIZE_PLUGINS"
 
 	// Modules
 	AirshipDefaultBootstrapImage = "quay.io/airshipit/isogen:latest-debian_stable"

pkg/document/bundle.go

@@ -22,6 +22,7 @@ import (
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/types"
 
+	"opendev.org/airship/airshipctl/pkg/environment"
 	utilyaml "opendev.org/airship/airshipctl/pkg/util/yaml"
 )
 
@@ -85,7 +86,7 @@ func NewBundle(fSys FileSystem, kustomizePath string) (Bundle, error) {
 		LoadRestrictions:     options.LoadRestrictions,
 		DoPrune:              false, // Default
 		PluginConfig: &types.PluginConfig{
-			AbsPluginHome:      kustomizePath,
+			AbsPluginHome:      environment.PluginPath(),
 			PluginRestrictions: types.PluginRestrictionsNone,
 		},
 	}

pkg/environment/settings.go

@@ -17,6 +17,7 @@ package environment
 import (
 	"os"
 	"path/filepath"
+	"sync"
 
 	"github.com/spf13/cobra"
 
@@ -35,6 +36,10 @@ type AirshipCTLSettings struct {
 	Config            *config.Config
 }
 
+// A singleton for the kustomize plugin path configuration
+var pluginPath string
+var pluginPathLock = &sync.Mutex{}
+
 // InitFlags adds the default settings flags to cmd
 func (a *AirshipCTLSettings) InitFlags(cmd *cobra.Command) {
 	flags := cmd.PersistentFlags()
@@ -67,6 +72,7 @@ func (a *AirshipCTLSettings) InitConfig() {
 
 	a.initAirshipConfigPath()
 	a.initKubeConfigPath()
+	initPluginPath()
 
 	err := a.Config.LoadConfig(a.AirshipConfigPath, a.KubeConfigPath)
 	if err != nil {
@@ -116,6 +122,28 @@ func (a *AirshipCTLSettings) initKubeConfigPath() {
 	a.KubeConfigPath = filepath.Join(homeDir, config.AirshipConfigDir, config.AirshipKubeConfig)
 }
 
+// Sets the location to look for kustomize plugins (including airshipctl itself).
+func initPluginPath() {
+	pluginPathLock.Lock()
+	defer pluginPathLock.Unlock()
+
+	// Check if we got the path via ENVIRONMENT variable
+	pluginPath = os.Getenv(config.AirshipPluginPathEnv)
+	if pluginPath != "" {
+		return
+	}
+
+	// Otherwise, we'll try putting it in the home directory
+	homeDir := userHomeDir()
+	pluginPath = filepath.Join(homeDir, config.AirshipConfigDir, config.AirshipPluginPath)
+}
+
+func PluginPath() string {
+	pluginPathLock.Lock()
+	defer pluginPathLock.Unlock()
+	return pluginPath
+}
+
 // userHomeDir is a utility function that wraps os.UserHomeDir and returns no
 // errors. If the user has no home directory, the returned value will be the
 // empty string

pkg/environment/settings_test.go

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-package environment
+package environment_test
 
 import (
 	"os"
@@ -25,12 +25,13 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"opendev.org/airship/airshipctl/pkg/config"
+	"opendev.org/airship/airshipctl/pkg/environment"
 	"opendev.org/airship/airshipctl/testutil"
 )
 
 func TestInitFlags(t *testing.T) {
 	// Get the Environment
-	settings := &AirshipCTLSettings{}
+	settings := &environment.AirshipCTLSettings{}
 	testCmd := &cobra.Command{}
 	settings.InitFlags(testCmd)
 	assert.True(t, testCmd.HasPersistentFlags())
@@ -43,13 +44,15 @@ func TestInitConfig(t *testing.T) {
 		defer cleanup(t)
 		defer setHome(testDir)()
 
-		var testSettings AirshipCTLSettings
+		var testSettings environment.AirshipCTLSettings
 		expectedAirshipConfig := filepath.Join(testDir, config.AirshipConfigDir, config.AirshipConfig)
 		expectedKubeConfig := filepath.Join(testDir, config.AirshipConfigDir, config.AirshipKubeConfig)
+		expectedPluginPath := filepath.Join(testDir, config.AirshipConfigDir, config.AirshipPluginPath)
 
 		testSettings.InitConfig()
 		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath)
 		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath)
+		assert.Equal(t, expectedPluginPath, environment.PluginPath())
 	})
 
 	t.Run("PreferEnvToDefault", func(subTest *testing.T) {
@@ -58,18 +61,22 @@ func TestInitConfig(t *testing.T) {
 		defer cleanup(t)
 		defer setHome(testDir)()
 
-		var testSettings AirshipCTLSettings
+		var testSettings environment.AirshipCTLSettings
 		expectedAirshipConfig := filepath.Join(testDir, "airshipEnv")
 		expectedKubeConfig := filepath.Join(testDir, "kubeEnv")
+		expectedPluginPath := filepath.Join(testDir, "pluginPath")
 
 		os.Setenv(config.AirshipConfigEnv, expectedAirshipConfig)
 		os.Setenv(config.AirshipKubeConfigEnv, expectedKubeConfig)
+		os.Setenv(config.AirshipPluginPathEnv, expectedPluginPath)
 		defer os.Unsetenv(config.AirshipConfigEnv)
 		defer os.Unsetenv(config.AirshipKubeConfigEnv)
+		defer os.Unsetenv(config.AirshipPluginPathEnv)
 
 		testSettings.InitConfig()
 		assert.Equal(t, expectedAirshipConfig, testSettings.AirshipConfigPath)
 		assert.Equal(t, expectedKubeConfig, testSettings.KubeConfigPath)
+		assert.Equal(t, expectedPluginPath, environment.PluginPath())
 	})
 
 	t.Run("PreferCmdLineArgToDefault", func(subTest *testing.T) {
@@ -81,7 +88,7 @@ func TestInitConfig(t *testing.T) {
 		expectedAirshipConfig := filepath.Join(testDir, "airshipCmdLine")
 		expectedKubeConfig := filepath.Join(testDir, "kubeCmdLine")
 
-		testSettings := AirshipCTLSettings{
+		testSettings := environment.AirshipCTLSettings{
 			AirshipConfigPath: expectedAirshipConfig,
 			KubeConfigPath:    expectedKubeConfig,
 		}
@@ -111,7 +118,7 @@ func TestInitConfig(t *testing.T) {
 		defer os.Unsetenv(config.AirshipConfigEnv)
 		defer os.Unsetenv(config.AirshipKubeConfigEnv)
 
-		testSettings := AirshipCTLSettings{
+		testSettings := environment.AirshipCTLSettings{
 			AirshipConfigPath: expectedAirshipConfig,
 			KubeConfigPath:    expectedKubeConfig,
 		}