Golang cli.Context類代碼示例

// mkCommandFunc executes the "mk" command.
func mkCommandFunc(c *cli.Context, ki client.KeysAPI) {
	if len(c.Args()) == 0 {
		handleError(ExitBadArgs, errors.New("key required"))
	}
	key := c.Args()[0]
	value, err := argOrStdin(c.Args(), os.Stdin, 1)
	if err != nil {
		handleError(ExitBadArgs, errors.New("value required"))
	}

	ttl := c.Int("ttl")

	ctx, cancel := contextWithTotalTimeout(c)
	// Since PrevNoExist means that the Node must not exist previously,
	// this Set method always creates a new key. Therefore, mk command
	// succeeds only if the key did not previously exist, and the command
	// prevents one from overwriting values accidentally.
	resp, err := ki.Set(ctx, key, value, &client.SetOptions{TTL: time.Duration(ttl) * time.Second, PrevExist: client.PrevNoExist})
	cancel()
	if err != nil {
		handleError(ExitServerError, err)
	}

	printResponseKey(resp, c.GlobalString("output"))
}

func actionMemberList(c *cli.Context) {
	if len(c.Args()) != 0 {
		fmt.Fprintln(os.Stderr, "No arguments accepted")
		os.Exit(1)
	}
	mAPI := mustNewMembersAPI(c)
	ctx, cancel := contextWithTotalTimeout(c)
	defer cancel()

	members, err := mAPI.List(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}
	leader, err := mAPI.Leader(ctx)
	if err != nil {
		fmt.Fprintln(os.Stderr, "Failed to get leader: ", err)
		os.Exit(1)
	}

	for _, m := range members {
		isLeader := false
		if m.ID == leader.ID {
			isLeader = true
		}
		if len(m.Name) == 0 {
			fmt.Printf("%s[unstarted]: peerURLs=%s\n", m.ID, strings.Join(m.PeerURLs, ","))
		} else {
			fmt.Printf("%s: name=%s peerURLs=%s clientURLs=%s isLeader=%v\n", m.ID, m.Name, strings.Join(m.PeerURLs, ","), strings.Join(m.ClientURLs, ","), isLeader)
		}
	}
}

// deleteRangeCommandFunc executes the "delegeRange" command.
func deleteRangeCommandFunc(c *cli.Context) {
	if len(c.Args()) == 0 {
		panic("bad arg")
	}

	var rangeEnd []byte
	key := []byte(c.Args()[0])
	if len(c.Args()) > 1 {
		rangeEnd = []byte(c.Args()[1])
	}
	conn, err := grpc.Dial(c.GlobalString("endpoint"))
	if err != nil {
		panic(err)
	}
	etcd := pb.NewEtcdClient(conn)
	req := &pb.DeleteRangeRequest{Key: key, RangeEnd: rangeEnd}

	etcd.DeleteRange(context.Background(), req)

	if rangeEnd != nil {
		fmt.Printf("range [%s, %s) is deleted\n", string(key), string(rangeEnd))
	} else {
		fmt.Printf("key %s is deleted\n", string(key))
	}
}

func newClient(c *cli.Context) (client.Client, error) {
	eps, err := getEndpoints(c)
	if err != nil {
		return nil, err
	}

	tr, err := getTransport(c)
	if err != nil {
		return nil, err
	}

	cfg := client.Config{
		Transport:               tr,
		Endpoints:               eps,
		HeaderTimeoutPerRequest: c.GlobalDuration("timeout"),
	}

	uFlag := c.GlobalString("username")
	if uFlag != "" {
		username, password, err := getUsernamePasswordFromFlag(uFlag)
		if err != nil {
			return nil, err
		}
		cfg.Username = username
		cfg.Password = password
	}

	return client.New(cfg)
}

func mustNewMembersAPI(c *cli.Context) client.MembersAPI {
	eps, err := getEndpoints(c)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	tr, err := getTransport(c)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	hc, err := client.NewHTTPClient(tr, eps)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	if !c.GlobalBool("no-sync") {
		ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
		err := hc.Sync(ctx)
		cancel()
		if err != nil {
			fmt.Fprintln(os.Stderr, err.Error())
			os.Exit(1)
		}
	}

	if c.GlobalBool("debug") {
		fmt.Fprintf(os.Stderr, "Cluster-Endpoints: %s\n", strings.Join(hc.Endpoints(), ", "))
	}

	return client.NewMembersAPI(hc)
}

// txnCommandFunc executes the "txn" command.
func txnCommandFunc(c *cli.Context) {
	if len(c.Args()) != 0 {
		panic("unexpected args")
	}

	reader := bufio.NewReader(os.Stdin)

	next := compareState
	txn := &pb.TxnRequest{}
	for next != nil {
		next = next(txn, reader)
	}

	conn, err := grpc.Dial("127.0.0.1:12379")
	if err != nil {
		panic(err)
	}
	etcd := pb.NewEtcdClient(conn)

	resp, err := etcd.Txn(context.Background(), txn)
	if err != nil {
		fmt.Println(err)
	}
	if resp.Succeeded {
		fmt.Println("executed success request list")
	} else {
		fmt.Println("executed failure request list")
	}
}

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

	return client.DeleteDir(key)
}

func mustNewAuthRoleAPI(c *cli.Context) client.AuthRoleAPI {
	hc := mustNewClient(c)

	if c.GlobalBool("debug") {
		fmt.Fprintf(os.Stderr, "Cluster-Endpoints: %s\n", strings.Join(hc.Endpoints(), ", "))
	}

	return client.NewAuthRoleAPI(hc)
}

func mustNewClient(c *cli.Context) client.Client {
	hc, err := newClient(c)
	if err != nil {
		fmt.Fprintln(os.Stderr, err.Error())
		os.Exit(1)
	}

	debug := c.GlobalBool("debug")
	if debug {
		client.EnablecURLDebug()
	}

	if !c.GlobalBool("no-sync") {
		if debug {
			fmt.Fprintf(os.Stderr, "start to sync cluster using endpoints(%s)\n", strings.Join(hc.Endpoints(), ","))
		}
		ctx, cancel := context.WithTimeout(context.Background(), client.DefaultRequestTimeout)
		err := hc.Sync(ctx)
		cancel()
		if err != nil {
			if err == client.ErrNoEndpoints {
				fmt.Fprintf(os.Stderr, "etcd cluster has no published client endpoints.\n")
				fmt.Fprintf(os.Stderr, "Try '--no-sync' if you want to access non-published client endpoints(%s).\n", strings.Join(hc.Endpoints(), ","))
				handleError(ExitServerError, err)
			}

			if isConnectionError(err) {
				handleError(ExitBadConnection, err)
			}

			// fail-back to try sync cluster with peer API. this is for making etcdctl work with etcd 0.4.x.
			// TODO: remove this when we deprecate the support for etcd 0.4.
			eps, serr := syncWithPeerAPI(c, ctx, hc.Endpoints())
			if serr != nil {
				if isConnectionError(serr) {
					handleError(ExitBadConnection, serr)
				} else {
					handleError(ExitServerError, serr)
				}
			}
			err = hc.SetEndpoints(eps)
			if err != nil {
				handleError(ExitServerError, err)
			}
		}
		if debug {
			fmt.Fprintf(os.Stderr, "got endpoints(%s) after sync\n", strings.Join(hc.Endpoints(), ","))
		}
	}

	if debug {
		fmt.Fprintf(os.Stderr, "Cluster-Endpoints: %s\n", strings.Join(hc.Endpoints(), ", "))
	}

	return hc
}

// lsCommandFunc executes the "ls" command.
func lsCommandFunc(c *cli.Context, client *etcd.Client) (*etcd.Response, error) {
	key := "/"
	if len(c.Args()) != 0 {
		key = c.Args()[0]
	}
	recursive := c.Bool("recursive")

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

// rPrint recursively prints out the nodes in the node structure.
func rPrint(c *cli.Context, n *client.Node) {
	if n.Dir && c.Bool("p") {
		fmt.Println(fmt.Sprintf("%v/", n.Key))
	} else {
		fmt.Println(n.Key)
	}

	for _, node := range n.Nodes {
		rPrint(c, node)
	}
}

func mustRoleAPIAndName(c *cli.Context) (client.AuthRoleAPI, string) {
	args := c.Args()
	if len(args) != 1 {
		fmt.Fprintln(os.Stderr, "Please provide a role name")
		os.Exit(1)
	}

	name := args[0]
	api := mustNewAuthRoleAPI(c)
	return api, name
}

func mustUserAPIAndName(c *cli.Context) (client.AuthUserAPI, string) {
	args := c.Args()
	if len(args) != 1 {
		fmt.Fprintln(os.Stderr, "Please provide a username")
		os.Exit(1)
	}

	api := mustNewAuthUserAPI(c)
	username := args[0]
	return api, username
}

// Just like handlePrint but also passed the context of the command
func handleContextualPrint(c *cli.Context, fn handlerFunc, pFn contextualPrintFunc) {
	resp, err := rawhandle(c, fn)

	if err != nil {
		handleError(ErrorFromEtcd, err)
	}

	if resp != nil && pFn != nil {
		pFn(c, resp, c.GlobalString("output"))
	}
}

// handlePrint wraps the command function handlers to parse global flags
// into a client and to properly format the response objects.
func handlePrint(c *cli.Context, fn handlerFunc, pFn printFunc) {
	resp, err := rawhandle(c, fn)

	// Print error and exit, if necessary.
	if err != nil {
		handleError(ErrorFromEtcd, err)
	}

	if resp != nil && pFn != nil {
		pFn(resp, c.GlobalString("output"))
	}
}