Add XDG_DATA_DIRS support for using plugins from multiple locs

This allows the user to set their plugin directories in
XDG_DATA_DIRS and based on the precedence, all the locations will
be searched for the particular plugin and be used.

Signed-off-by: Vibhav Bobade <vibhav.bobde@gmail.com>

cmd/helm/load_plugins.go

@@ -58,7 +58,7 @@ func loadPlugins(baseCmd *cobra.Command, out io.Writer) {
 		return
 	}
 
-	found, err := plugin.FindPlugins(settings.PluginsDirectory)
+	found, err := plugin.FindPlugins(settings.PluginsDirectories)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "failed to load plugins: %s", err)
 		return

cmd/helm/plugin_test.go

@@ -78,6 +78,7 @@ func TestManuallyProcessArgs(t *testing.T) {
 
 func TestLoadPlugins(t *testing.T) {
 	settings.PluginsDirectory = "testdata/helmhome/helm/plugins"
+	settings.PluginsDirectories = "testdata/helmhome/helm/plugins"
 	settings.RepositoryConfig = "testdata/helmhome/helm/repositories.yaml"
 	settings.RepositoryCache = "testdata/helmhome/helm/repository"
 
@@ -155,6 +156,86 @@ func TestLoadPlugins(t *testing.T) {
 	}
 }
 
+func TestLoadPluginsFromDifferentLocations(t *testing.T) {
+	settings.PluginsDirectory = "testdata/helmhome/helm/plugins_1"
+	settings.PluginsDirectories = "testdata/helmhome/helm/plugins_1:testdata/helmhome/helm/plugins_2"
+	settings.RepositoryConfig = "testdata/helmhome/helm/repositories.yaml"
+	settings.RepositoryCache = "testdata/helmhome/helm/repository"
+
+	var (
+		out bytes.Buffer
+		cmd cobra.Command
+	)
+	loadPlugins(&cmd, &out)
+
+	envs := strings.Join([]string{
+		"fullenv",
+		"testdata/helmhome/helm/plugins_1/fullenv",
+		"testdata/helmhome/helm/plugins_1",
+		"testdata/helmhome/helm/repositories.yaml",
+		"testdata/helmhome/helm/repository",
+		os.Args[0],
+	}, "\n")
+
+	// Test that the YAML file was correctly converted to a command.
+	tests := []struct {
+		use    string
+		short  string
+		long   string
+		expect string
+		args   []string
+		code   int
+	}{
+		{"args", "echo args", "This echos args", "-a -b -c\n", []string{"-a", "-b", "-c"}, 0},
+		{"echo", "echo stuff", "This echos stuff", "hello\n", []string{}, 0},
+		{"env", "env stuff", "show the env", "env\n", []string{}, 0},
+		{"exitwith", "exitwith code", "This exits with the specified exit code", "", []string{"2"}, 2},
+		{"fullenv", "show env vars", "show all env vars", envs + "\n", []string{}, 0},
+	}
+
+	plugins := cmd.Commands()
+
+	if len(plugins) != len(tests) {
+		t.Fatalf("Expected %d plugins, got %d", len(tests), len(plugins))
+	}
+
+	for i := 0; i < len(plugins); i++ {
+		out.Reset()
+		tt := tests[i]
+		pp := plugins[i]
+		if pp.Use != tt.use {
+			t.Errorf("%d: Expected Use=%q, got %q", i, tt.use, pp.Use)
+		}
+		if pp.Short != tt.short {
+			t.Errorf("%d: Expected Use=%q, got %q", i, tt.short, pp.Short)
+		}
+		if pp.Long != tt.long {
+			t.Errorf("%d: Expected Use=%q, got %q", i, tt.long, pp.Long)
+		}
+
+		// Currently, plugins assume a Linux subsystem. Skip the execution
+		// tests until this is fixed
+		if runtime.GOOS != "windows" {
+			if err := pp.RunE(pp, tt.args); err != nil {
+				if tt.code > 0 {
+					perr, ok := err.(pluginError)
+					if !ok {
+						t.Errorf("Expected %s to return pluginError: got %v(%T)", tt.use, err, err)
+					}
+					if perr.code != tt.code {
+						t.Errorf("Expected %s to return %d: got %d", tt.use, tt.code, perr.code)
+					}
+				} else {
+					t.Errorf("Error running %s: %+v", tt.use, err)
+				}
+			}
+			if out.String() != tt.expect {
+				t.Errorf("Expected %s to output:\n%s\ngot\n%s", tt.use, tt.expect, out.String())
+			}
+		}
+	}
+}
+
 type staticCompletionDetails struct {
 	use       string
 	validArgs []string
@@ -279,6 +360,7 @@ func TestPluginDynamicCompletion(t *testing.T) {
 	}}
 	for _, test := range tests {
 		settings.PluginsDirectory = "testdata/helmhome/helm/plugins"
+		settings.PluginsDirectories = "testdata/helmhome/helm/plugins"
 		runTestCmd(t, []cmdTestCase{test})
 	}
 }

cmd/helm/testdata/helmhome/helm/plugins_1/env/completion.yaml

@@ -0,0 +1,13 @@
+name: env
+commands:
+  - name: list
+    flags:
+    - a
+    - all
+    - log
+  - name: remove
+    validArgs:
+    - all
+    - one
+flags:
+- global

cmd/helm/testdata/helmhome/helm/plugins_1/env/plugin.yaml

@@ -0,0 +1,4 @@
+name: env
+usage: "env stuff"
+description: "show the env"
+command: "echo $HELM_PLUGIN_NAME"

cmd/helm/testdata/helmhome/helm/plugins_1/exitwith/completion.yaml

@@ -0,0 +1,5 @@
+commands:
+  - name: code
+    flags:
+    - a
+    - b

cmd/helm/testdata/helmhome/helm/plugins_1/exitwith/exitwith.sh

@@ -0,0 +1,2 @@
+#!/bin/bash
+exit $*

cmd/helm/testdata/helmhome/helm/plugins_1/exitwith/plugin.yaml

@@ -0,0 +1,4 @@
+name: exitwith
+usage: "exitwith code"
+description: "This exits with the specified exit code"
+command: "$HELM_PLUGIN_DIR/exitwith.sh"

cmd/helm/testdata/helmhome/helm/plugins_1/fullenv/completion.yaml

@@ -0,0 +1,19 @@
+name: wrongname
+commands:
+  - name: empty
+  - name: full
+    commands:
+    - name: more
+      validArgs:
+      - one
+      - two
+      flags:
+      - b
+      - ball
+    - name: less
+      flags:
+      - a
+      - all
+flags:
+- z
+- q

cmd/helm/testdata/helmhome/helm/plugins_1/fullenv/fullenv.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+echo $HELM_PLUGIN_NAME
+echo $HELM_PLUGIN_DIR
+echo $HELM_PLUGINS
+echo $HELM_REPOSITORY_CONFIG
+echo $HELM_REPOSITORY_CACHE
+echo $HELM_BIN

cmd/helm/testdata/helmhome/helm/plugins_1/fullenv/plugin.yaml

@@ -0,0 +1,4 @@
+name: fullenv
+usage: "show env vars"
+description: "show all env vars"
+command: "$HELM_PLUGIN_DIR/fullenv.sh"

cmd/helm/testdata/helmhome/helm/plugins_2/args/args.sh

@@ -0,0 +1,2 @@
+#!/bin/bash
+echo $*

cmd/helm/testdata/helmhome/helm/plugins_2/args/plugin.complete

@@ -0,0 +1,13 @@
+#!/usr/bin/env sh
+
+echo "plugin.complete was called"
+echo "Namespace: ${HELM_NAMESPACE:-NO_NS}"
+echo "Num args received: ${#}"
+echo "Args received: ${@}"
+
+# Final printout is the optional completion directive of the form :<directive>
+if [ "$HELM_NAMESPACE" = "default" ]; then
+    echo ":4"
+else
+    echo ":2"
+fi

cmd/helm/testdata/helmhome/helm/plugins_2/args/plugin.yaml

@@ -0,0 +1,4 @@
+name: args
+usage: "echo args"
+description: "This echos args"
+command: "$HELM_PLUGIN_DIR/args.sh"

cmd/helm/testdata/helmhome/helm/plugins_2/echo/plugin.complete

@@ -0,0 +1,14 @@
+#!/usr/bin/env sh
+
+echo "echo plugin.complete was called"
+echo "Namespace: ${HELM_NAMESPACE:-NO_NS}"
+echo "Num args received: ${#}"
+echo "Args received: ${@}"
+
+# Final printout is the optional completion directive of the form :<directive>
+if [ "$HELM_NAMESPACE" = "default" ]; then
+    # Output an invalid directive, which should be ignored
+    echo ":2222"
+# else
+    # Don't include the directive, to test it is really optional
+fi

cmd/helm/testdata/helmhome/helm/plugins_2/echo/plugin.yaml

@@ -0,0 +1,4 @@
+name: echo
+usage: "echo stuff"
+description: "This echos stuff"
+command: "echo hello"

internal/test/ensure/ensure.go

@@ -20,6 +20,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 	"testing"
 
 	"helm.sh/helm/v3/pkg/helmpath"
@@ -33,6 +34,7 @@ func HelmHome(t *testing.T) func() {
 	os.Setenv(xdg.CacheHomeEnvVar, base)
 	os.Setenv(xdg.ConfigHomeEnvVar, base)
 	os.Setenv(xdg.DataHomeEnvVar, base)
+	os.Setenv(xdg.DataDirsEnvVar, strings.Join([]string{base, os.Getenv(xdg.DataDirsEnvVar)}, ":"))
 	os.Setenv(helmpath.CacheHomeEnvVar, "")
 	os.Setenv(helmpath.ConfigHomeEnvVar, "")
 	os.Setenv(helmpath.DataHomeEnvVar, "")

pkg/cli/environment.go

@@ -26,6 +26,9 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
+
+	"helm.sh/helm/v3/pkg/helmpath/xdg"
 
 	"github.com/spf13/pflag"
 	"k8s.io/cli-runtime/pkg/genericclioptions"
@@ -56,6 +59,8 @@ type EnvSettings struct {
 	RepositoryCache string
 	// PluginsDirectory is the path to the plugins directory.
 	PluginsDirectory string
+	// PluginsDirectories contains colon separated locations to different possible plugin directories
+	PluginsDirectories string
 }
 
 func New() *EnvSettings {
@@ -65,6 +70,8 @@ func New() *EnvSettings {
 		KubeToken:        os.Getenv("HELM_KUBETOKEN"),
 		KubeAPIServer:    os.Getenv("HELM_KUBEAPISERVER"),
 		PluginsDirectory: envOr("HELM_PLUGINS", helmpath.DataPath("plugins")),
+		PluginsDirectories: strings.Join([]string{envOr("HELM_PLUGINS", helmpath.DataPath("plugins")),
+			os.Getenv(xdg.DataDirsEnvVar)}, ":"),
 		RegistryConfig:   envOr("HELM_REGISTRY_CONFIG", helmpath.ConfigPath("registry.json")),
 		RepositoryConfig: envOr("HELM_REPOSITORY_CONFIG", helmpath.ConfigPath("repositories.yaml")),
 		RepositoryCache:  envOr("HELM_REPOSITORY_CACHE", helmpath.CachePath("repository")),

pkg/helmpath/home.go

@@ -26,6 +26,9 @@ func CachePath(elem ...string) string { return lp.cachePath(elem...) }
 // DataPath returns the path where Helm stores data.
 func DataPath(elem ...string) string { return lp.dataPath(elem...) }
 
+// DataDirs returns the paths where Helm can store data.
+func DataDirs(elem string) string { return lp.dataDirs(elem) }
+
 // CacheIndexFile returns the path to an index for the given named repository.
 func CacheIndexFile(name string) string {
 	if name != "" {

pkg/helmpath/lazypath.go

@@ -16,6 +16,7 @@ package helmpath
 import (
 	"os"
 	"path/filepath"
+	"strings"
 
 	"helm.sh/helm/v3/pkg/helmpath/xdg"
 )
@@ -43,10 +44,13 @@ func (l lazypath) path(helmEnvVar, xdgEnvVar string, defaultFn func() string, el
 	// 1. See if a Helm specific environment variable has been set.
 	// 2. Check if an XDG environment variable is set
 	// 3. Fall back to a default
-	base := os.Getenv(helmEnvVar)
+	base := ""
+	if helmEnvVar != "" {
+		base = os.Getenv(helmEnvVar)
 		if base != "" {
 			return filepath.Join(base, filepath.Join(elem...))
 		}
+	}
 	base = os.Getenv(xdgEnvVar)
 	if base == "" {
 		base = defaultFn()
@@ -70,3 +74,10 @@ func (l lazypath) configPath(elem ...string) string {
 func (l lazypath) dataPath(elem ...string) string {
 	return l.path(DataHomeEnvVar, xdg.DataHomeEnvVar, dataHome, filepath.Join(elem...))
 }
+
+// dataDirs defines all the base directories in order of precedence separated by colon
+// relative to which user specific data files can be stored.
+// Not exposed on Helm side but used internally
+func (l lazypath) dataDirs(elem ...string) string {
+	return l.path("", xdg.DataDirsEnvVar, dataDirs, strings.Join(elem, ":"))
+}

pkg/helmpath/lazypath_unix.go

@@ -16,7 +16,11 @@
 package helmpath
 
 import (
+	"os"
 	"path/filepath"
+	"strings"
+
+	"helm.sh/helm/v3/pkg/helmpath/xdg"
 
 	"k8s.io/client-go/util/homedir"
 )
@@ -43,3 +47,7 @@ func configHome() string {
 func cacheHome() string {
 	return filepath.Join(homedir.HomeDir(), ".cache")
 }
+
+func dataDirs() string {
+	return strings.Join([]string{dataHome(), os.Getenv(xdg.DataDirsEnvVar)}, ":")
+}

pkg/helmpath/xdg/xdg.go

@@ -31,4 +31,9 @@ const (
 	// DataHomeEnvVar is the environment variable used by the
 	// XDG base directory specification for the data directory.
 	DataHomeEnvVar = "XDG_DATA_HOME"
+
+	// DataDirsEnvVar is the environment variable contains
+	// preference order set of base directories separated by a
+	// colon ":".
+	DataDirsEnvVar = "XDG_DATA_DIRS"
 )