etcd-io__etcd/etcdctl/command/get_command.go

/*
   Copyright 2014 CoreOS, Inc.

   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 command

import (
	"errors"
	"fmt"
	"os"

	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/codegangsta/cli"
	"github.com/coreos/etcd/Godeps/_workspace/src/github.com/coreos/go-etcd/etcd"
)

// NewGetCommand returns the CLI command for "get".
func NewGetCommand() cli.Command {
	return cli.Command{
		Name:  "get",
		Usage: "retrieve the value of a key",
		Flags: []cli.Flag{
			cli.BoolFlag{Name: "sort", Usage: "returns result in sorted order"},
			cli.BoolFlag{Name: "consistent", Usage: "send request to the leader, thereby guranteeing that any earlier writes will be seen by the read"},
		},
		Action: func(c *cli.Context) {
			handleGet(c, getCommandFunc)
		},
	}
}

// handleGet handles a request that intends to do get-like operations.
func handleGet(c *cli.Context, fn handlerFunc) {
	handlePrint(c, fn, printGet)
}

// printGet writes error message when getting the value of a directory.
func printGet(resp *etcd.Response, format string) {
	if resp.Node.Dir {
		fmt.Fprintln(os.Stderr, fmt.Sprintf("%s: is a directory", resp.Node.Key))
		os.Exit(1)
	}

	printKey(resp, format)
}

// getCommandFunc executes the "get" command.
func getCommandFunc(c *cli.Context, client *etcd.Client) (*etcd.Response, error) {
	if len(c.Args()) == 0 {
		return nil, errors.New("Key required")
	}
	key := c.Args()[0]
	consistent := c.Bool("consistent")
	sorted := c.Bool("sort")

	// Setup consistency on the client.
	if consistent {
		client.SetConsistency(etcd.STRONG_CONSISTENCY)
	} else {
		client.SetConsistency(etcd.WEAK_CONSISTENCY)
	}

	// Retrieve the value from the server.
	return client.Get(key, sorted, false)
}