refactor down to one file, as the implementation is the same

cmd/list.go

@@ -0,0 +1,127 @@
+/*
+Copyright © 2019 Zee Ahmed <zee@simplyzee.dev>
+
+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 cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+
+	"github.com/spf13/cobra"
+)
+
+const (
+	binaryListURL = "https://api.github.com/repos/kubernetes/kubernetes/releases?per_page=100"
+)
+
+var (
+	remote bool
+)
+
+type kubectlVersion struct {
+	TagName string `json:"tag_name"`
+}
+
+var listCmd = &cobra.Command{
+	Use:   "list",
+	Short: "List downloaded kubectl binaries",
+	Run: func(cmd *cobra.Command, args []string) {
+		var versions []kubectlVersion
+		if remote {
+			fmt.Println("Fetching remote versions ...")
+			versions = fetchRemoteVersions()
+		} else {
+			versions = fetchLocalVersions()
+
+			if len(versions) > 0 {
+				fmt.Println("Installed kubectl versions:")
+			} else {
+				fmt.Println("No versions installed. See 'kubemngr list --remote' for available versions.")
+			}
+		}
+
+		for _, version := range versions {
+			// only show stable releases
+			filterStable := strings.NewReplacer(
+				"-rc.1", "",
+				"-beta.2", "",
+				"-beta.1", "",
+				"-alpha.3", "",
+				"-alpha.2", "",
+				"-alpha.1", "",
+				"-rc.2", "",
+				"-rc.3", "",
+			)
+			stable := filterStable.Replace(version.TagName)
+
+			fmt.Println(stable)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(listCmd)
+	listCmd.Flags().BoolVar(&remote, "remote", false, "Get versions from remote")
+}
+
+// fetchLocalVersions - List available installed kubectl versions
+func fetchLocalVersions() []kubectlVersion {
+	homeDir, err := os.UserHomeDir()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	kubectl, err := ioutil.ReadDir(homeDir + "/.kubemngr/")
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	list := []kubectlVersion{}
+	for _, files := range kubectl {
+		file := files.Name()
+		version := strings.Replace(file, "kubectl-", "", -1)
+		list = append(list, kubectlVersion{TagName: version})
+	}
+
+	return list
+}
+
+// fetchRemoteVersions lists Kubectl binaries available at the configured remote location
+func fetchRemoteVersions() []kubectlVersion {
+	res, err := http.Get(binaryListURL)
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer res.Body.Close()
+
+	body, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	list := []kubectlVersion{}
+	jsonErr := json.Unmarshal(body, &list)
+	if jsonErr != nil {
+		log.Fatal(jsonErr)
+	}
+
+	return list
+}