[FEATURE] Plugin System

cmd/plugin/plugin.go

@@ -0,0 +1,54 @@
+/*
+Copyright © 2020-2021 The k3d Author(s)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package plugin
+
+import (
+	l "github.com/rancher/k3d/v4/pkg/logger"
+
+	"github.com/spf13/cobra"
+)
+
+// NewCmdPlugin returns a new cobra command
+func NewCmdPlugin() *cobra.Command {
+
+	// create new cobra command
+	cmd := &cobra.Command{
+		Use:   "plugin",
+		Short: "Manage plugins",
+		Long:  `Manage plugins`,
+		Run: func(cmd *cobra.Command, args []string) {
+			if err := cmd.Help(); err != nil {
+				l.Log().Errorln("Couldn't get help text")
+				l.Log().Fatalln(err)
+			}
+		},
+	}
+
+	// add subcommands
+	cmd.AddCommand(NewCmdPluginInstall())
+	cmd.AddCommand(NewCmdPluginRemove())
+
+	// add flags
+
+	// done
+	return cmd
+}

cmd/plugin/pluginInstall.go

@@ -0,0 +1,161 @@
+/*
+Copyright © 2020-2021 The k3d Author(s)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package plugin
+
+import (
+	"bufio"
+	"log"
+	"os"
+	"path"
+
+	"github.com/rancher/k3d/v4/cmd/util"
+	l "github.com/rancher/k3d/v4/pkg/logger"
+	utils "github.com/rancher/k3d/v4/pkg/util"
+	"github.com/spf13/cobra"
+	"golang.org/x/term"
+)
+
+// NewCmdPluginInstall returns a new cobra command
+func NewCmdPluginInstall() *cobra.Command {
+
+	// create new cobra command
+	cmd := &cobra.Command{
+		Use:   "install PLUGIN [PLUGIN...]",
+		Short: "Install a plugin",
+		Long: `Install a plugin
+
+Examples:
+  To install one plugin, run:
+    k3d plugin install user/plugin
+
+  To install the specific version of a plugin, use:
+    k3d plugin install user/plugin@v0.0.1
+
+  If you have a list of plugins in a file, run:
+    k3d plugin install < plugins.txt
+
+Remarks:
+  If a plugin is already installed, it will be overridden.
+`,
+		Run: func(cmd *cobra.Command, args []string) {
+			warnIfNotATerminal()
+			printHelpIfNoArgs(cmd, args)
+
+			plugins := getPlugins(args)
+
+			// Get the path of the plugin folder
+			pluginDir, err := utils.GetPluginDirOrCreate()
+			if err != nil {
+				l.Log().Fatal(err)
+			}
+
+			// Install all plugins
+			for _, plugin := range plugins {
+				// Get the plugin path
+				pluginPath := path.Join(pluginDir, plugin.Name)
+
+				// Download the plugin
+				l.Log().Infof("Installing plugin %s", plugin.Name)
+				err = util.DownloadPlugin(*plugin, pluginPath)
+				if err != nil {
+					l.Log().Errorf("Unable to download %s@%s", plugin.Name, plugin.Version)
+					l.Log().Fatal(err)
+				}
+
+				l.Log().Debug("Changing file permissions")
+				if err = os.Chmod(pluginPath, 0744); err != nil {
+					l.Log().Errorf("Error while changing file permissions: %s", err)
+				}
+
+				l.Log().Infof("Plugin %s installed successfully", plugin.Name)
+			}
+		},
+	}
+
+	// add subcommands
+
+	// add flags
+
+	// done
+	return cmd
+}
+
+// getPlugins reads plugins from the stdin if it is a file descriptor
+// or from command args
+func getPlugins(pluginNames []string) []*util.Plugin {
+	// Ignore args if adding plugins using stdin
+	if !term.IsTerminal(int(os.Stdin.Fd())) {
+		pluginNames = readPluginsFromStdin()
+	}
+	plugins := parsePlugins(pluginNames)
+
+	return plugins
+}
+
+// parsePlugins reads a list of plugin names and returns the list of corresponding Plugins
+func parsePlugins(pluginNames []string) []*util.Plugin {
+	var plugins = make([]*util.Plugin, len(pluginNames))
+
+	// Read plugins from args
+	for index, pluginName := range pluginNames {
+		plugin, err := util.NewPlugin(pluginName)
+		if err != nil {
+			log.Fatal(err)
+		}
+		plugins[index] = plugin
+	}
+
+	return plugins
+}
+
+// readPluginsFromStdin reads plugin names from os.Stdin.
+// Returns the list of plugin names.
+func readPluginsFromStdin() []string {
+	var pluginNames []string
+
+	scanner := bufio.NewScanner(os.Stdin)
+	scanner.Split(bufio.ScanLines)
+	for scanner.Scan() {
+		if pluginName := scanner.Text(); pluginName != "" {
+			pluginNames = append(pluginNames, pluginName)
+		}
+	}
+
+	return pluginNames
+}
+
+// Log a warning if the stdin is not a terminal
+func warnIfNotATerminal() {
+	if !term.IsTerminal(int(os.Stdin.Fd())) {
+		l.Log().Warn("Stdin detected")
+	}
+}
+
+// Show help and exit if k3d is launched in a terminal and there are 0 args
+func printHelpIfNoArgs(cmd *cobra.Command, args []string) {
+	if term.IsTerminal(int(os.Stdin.Fd())) && len(args) == 0 {
+		if err := cmd.Help(); err != nil {
+			l.Log().Errorln("Couldn't get help text")
+			l.Log().Fatalln(err)
+		}
+	}
+}

cmd/plugin/pluginRemove.go

@@ -0,0 +1,51 @@
+/*
+Copyright © 2020-2021 The k3d Author(s)
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+package plugin
+
+import (
+	l "github.com/rancher/k3d/v4/pkg/logger"
+	"github.com/spf13/cobra"
+)
+
+// NewCmdPluginRemove returns a new cobra command
+func NewCmdPluginRemove() *cobra.Command {
+
+	// create new cobra command
+	cmd := &cobra.Command{
+		Use:   "remove PLUGIN",
+		Short: "Remove a plugin",
+		Long:  `Remove a plugin`,
+		Run: func(cmd *cobra.Command, args []string) {
+			if err := cmd.Help(); err != nil {
+				l.Log().Errorln("Couldn't get help text")
+				l.Log().Fatalln(err)
+			}
+		},
+	}
+
+	// add subcommands
+
+	// add flags
+
+	// done
+	return cmd
+}

cmd/root.go

@@ -38,6 +38,7 @@ import (
 	"github.com/rancher/k3d/v4/cmd/image"
 	"github.com/rancher/k3d/v4/cmd/kubeconfig"
 	"github.com/rancher/k3d/v4/cmd/node"
+	"github.com/rancher/k3d/v4/cmd/plugin"
 	"github.com/rancher/k3d/v4/cmd/registry"
 	cliutil "github.com/rancher/k3d/v4/cmd/util"
 	l "github.com/rancher/k3d/v4/pkg/logger"
@@ -94,6 +95,7 @@ All Nodes of a k3d cluster are part of the same docker network.`,
 	rootCmd.AddCommand(cfg.NewCmdConfig())
 	rootCmd.AddCommand(registry.NewCmdRegistry())
 	rootCmd.AddCommand(debug.NewCmdDebug())
+	rootCmd.AddCommand(plugin.NewCmdPlugin())
 
 	rootCmd.AddCommand(&cobra.Command{
 		Use:   "version",

cmd/util/plugin.go

@@ -0,0 +1,52 @@
+package util
+
+import (
+	"errors"
+	"strings"
+)
+
+type Plugin struct {
+	Name       string
+	Repository string
+	Version    string
+}
+
+// NewPlugin parses plugin parameter into repository name and version
+// and maps the result in a Plugin struct
+//
+// plugin must be formatted as owner/repo or owner/repo@version
+// if no version is specified, latest will be used
+func NewPlugin(plugin string) (*Plugin, error) {
+	splitted := strings.Split(plugin, "@")
+	repository := splitted[0]
+
+	// Use latest if version is not specified
+	version := "latest"
+	if len(splitted) > 1 {
+		version = splitted[1]
+	}
+
+	name, err := parseName(repository)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Plugin{
+		Name:       name,
+		Repository: repository,
+		Version:    version,
+	}, nil
+}
+
+// parseName parses the name of the plugin given the repository
+// return an error if unable to parse the name
+func parseName(repository string) (string, error) {
+	splitted := strings.Split(repository, "/")
+
+	// A plugin name must be formatted as owner/pluginName
+	if len(splitted) != 2 {
+		return "", errors.New("Error parsing the plugin name, it should be formatted as owner/repository")
+	}
+
+	return splitted[1], nil
+}