[GSoC 2019] kubectl plugin for the Postgres operator (#579)

*  Add a prototype of a kubectl plugin for the Postgres operator
   Work done by Vineeth Pothulapati <vineethpothulapati@outlook.com>
   during Google Summer of Code 2019

kubectl-pg/cmd/create.go

@@ -0,0 +1,76 @@
+/*
+Copyright © 2019 Vineeth Pothulapati <vineethpothulapati@outlook.com>
+
+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 cmd
+
+import (
+	"fmt"
+	"github.com/spf13/cobra"
+	v1 "github.com/zalando/postgres-operator/pkg/apis/acid.zalan.do/v1"
+	PostgresqlLister "github.com/zalando/postgres-operator/pkg/generated/clientset/versioned/typed/acid.zalan.do/v1"
+	"io/ioutil"
+	"k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset/scheme"
+	"log"
+)
+
+// createCmd kubectl pg create.
+var createCmd = &cobra.Command{
+	Use:   "create",
+	Short: "Creates postgres object using manifest file",
+	Long:  `Creates postgres custom resource objects from a manifest file.`,
+	Run: func(cmd *cobra.Command, args []string) {
+		fileName, _ := cmd.Flags().GetString("file")
+		create(fileName)
+	},
+	Example: `
+kubectl pg create -f cluster-manifest.yaml
+`,
+}
+
+// Create postgresql resources.
+func create(fileName string) {
+	config := getConfig()
+	postgresConfig, err := PostgresqlLister.NewForConfig(config)
+	ymlFile, err := ioutil.ReadFile(fileName)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	decode := scheme.Codecs.UniversalDeserializer().Decode
+	obj, _, err := decode([]byte(ymlFile), nil, &v1.Postgresql{})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	postgresSql := obj.(*v1.Postgresql)
+	_, err = postgresConfig.Postgresqls(postgresSql.Namespace).Create(postgresSql)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	fmt.Printf("postgresql %s created.\n", postgresSql.Name)
+}
+
+func init() {
+	createCmd.Flags().StringP("file", "f", "", "manifest file with the cluster definition.")
+	rootCmd.AddCommand(createCmd)
+}