add porter get command

cli/cmd/get.go

@@ -0,0 +1,77 @@
+package cmd
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	api "github.com/porter-dev/porter/api/client"
+	"github.com/porter-dev/porter/api/types"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v2"
+)
+
+// getCmd represents the "porter get" base command when called
+// without any subcommands
+var getCmd = &cobra.Command{
+	Use:   "get [release]",
+	Args:  cobra.ExactArgs(1),
+	Short: "Fetches a release.",
+	Run: func(cmd *cobra.Command, args []string) {
+		err := checkLoginAndRun(args, get)
+
+		if err != nil {
+			os.Exit(1)
+		}
+	},
+}
+
+var output string
+
+func init() {
+	rootCmd.AddCommand(getCmd)
+
+	getCmd.PersistentFlags().StringVar(
+		&namespace,
+		"namespace",
+		"default",
+		"the namespace of the release",
+	)
+
+	getCmd.PersistentFlags().StringVar(
+		&output,
+		"output",
+		"yaml",
+		"the output format to use (\"yaml\" or \"json\")",
+	)
+}
+
+func get(_ *types.GetAuthenticatedUserResponse, client *api.Client, args []string) error {
+	rel, err := client.GetRelease(context.Background(), config.Project, config.Cluster, namespace, args[0])
+	if err != nil {
+		return err
+	}
+
+	var bytes []byte
+
+	if output == "yaml" {
+		bytes, err = yaml.Marshal(rel)
+
+		if err != nil {
+			return err
+		}
+	} else if output == "json" {
+		bytes, err = json.Marshal(rel)
+
+		if err != nil {
+			return err
+		}
+	} else {
+		return fmt.Errorf("invalid output format: %s", output)
+	}
+
+	fmt.Println(string(bytes))
+
+	return nil
+}