Go使用etcd

1. 概述

在上一篇文章 etcd学习中我们搭建好了 Etcd 集群，并使用 etcdctl 进行了大部分命令的测试，这篇文章，将使用 golang 来对接 etcd 的这些命令。

go get go.etcd.io/etcd/client/v3

以下是各个模块及命令的使用情况，所有代码托管在 Github ：

模块	命令	说明	进度
version	version	查看版本信息	—
endpoint	endpoint status	查看节点状态	✅
	endpoint hashkv	查看节点历史hash	✅
	endpoint health	查看节点健康状况	—
member	member list	获取成员列表	✅
	member add	添加成员	✅
	member update	更新成员	✅
	member promote	提升学习者成员为常规成员	✅
	member remove	移除成员	✅
move-leader	move-leader	将节点设为leader	✅
auth	auth status	查看当前鉴权开启状态	✅
	auth disable	禁用鉴权	✅
	auth enable	启用鉴权	✅
role	role list	获取角色列表	✅
	role add	添加角色	✅
	role get	查看角色信息	✅
	role delete	删除角色	✅
	role grant-permission	角色授权	✅
	role revoke-permission	撤销角色授权	✅
user	user add	添加用户	✅
	user list	用户列表	✅
	user get	获取用户信息	✅
	user delete	删除用户	✅
	user passwd	修改密码	✅
	user grant-role	用户绑定角色	✅
	user revoke-role	撤销用户角色	✅
lease	lease list	租约列表	✅
	lease grant	生成租约	✅
	lease revoke	撤销租约	✅
	lease timetolive	查看租约期限信息	✅
	lease keep-alive	保持租约不过期	✅
normal	put	设置kv	✅
	get	查看kv	✅
	del	删除kv	✅
	watch	监听key	✅
txn	txn	开启事务	✅
lock	lock	分布式锁	✅
snapshot	snapshot save	保存快照	✅
	snapshot status	校验快照	—
	snapshot restore	从快照恢复	—
alarm	alarm list	获取警报列表	✅
	alarm disarm	解除警报	✅
check	check datascale	检查内存使用情况	✅
	check perf	查看集群性能	✅
other	compaction	压缩 etcd 中的事件历史	—
	completion	生成完成脚本	—
	defrag	对具有给定端点的 etcd 成员的存储进行碎片整理	—
	elect	观察并参与leader选举	—
	make-mirror	在目标 etcd 集群上创建镜像	—

2. 使用

代码中 helper.PrintJSON(res) 只是一个简单的封装打印的方法，目的就是将响应结果打印为 json。

package helper

import (
	"encoding/json"
	"fmt"
)

// PrintJSON 打印Json
func PrintJSON(v interface{}) {
	b, _ := json.Marshal(v)
	fmt.Printf("%s\n", b)
}

2.1 endpoint

endpoint 封装了 endpoint status 和 endpoint hashkv 两个命令的方法，如下：

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
)

// Status 查看状态
func Status() error {
	for _, v := range cli.Endpoints() {
		res, err := cli.Status(ctx, v)
		if err != nil {
			return err
		}
		helper.PrintJSON(res)
	}
	return nil
}

// HashKV 查看节点历史hash
func HashKV() error {
	for _, v := range cli.Endpoints() {
		res, err := cli.HashKV(ctx, v, 0)
		if err != nil {
			return err
		}
		helper.PrintJSON(res)
	}
	return nil
}

2.2 member / move-leader

package base

import "github.com/jormin/etcd-demo/pkg/helper"

// MemberList 节点列表
func MemberList() error {
	res, err := cli.MemberList(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MemberAdd 添加常规节点
func MemberAdd(peerAddrs []string) error {
	res, err := cli.MemberAdd(ctx, peerAddrs)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MemberAddLearner 添加学习者节点
func MemberAddLearner(peerAddrs []string) error {
	res, err := cli.MemberAddAsLearner(ctx, peerAddrs)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MemberUpdate 成员更新
func MemberUpdate(id uint64, peerAddrs []string) error {
	res, err := cli.MemberUpdate(ctx, id, peerAddrs)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MemberPromote 提升学习者节点为常规节点
func MemberPromote(id uint64) error {
	res, err := cli.MemberPromote(ctx, id)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MemberRemove 删除成员
func MemberRemove(id uint64) error {
	res, err := cli.MemberRemove(ctx, id)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// MoveLeader 提升为leader
func MoveLeader(id uint64) error {
	res, err := cli.MoveLeader(ctx, id)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.3 auth

package base

import "github.com/jormin/etcd-demo/pkg/helper"

// AuthStatus 获取鉴权开启状态
func AuthStatus() error {
	res, err := cli.AuthStatus(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// AuthDisable 关闭鉴权
func AuthDisable() error {
	res, err := cli.AuthDisable(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// AuthEnable 启动鉴权
func AuthEnable() error {
	res, err := cli.AuthEnable(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.4 role

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// RoleList 获取角色列表
func RoleList() error {
	res, err := cli.RoleList(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// RoleAdd 添加角色
func RoleAdd(role string) error {
	res, err := cli.RoleAdd(ctx, role)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// RoleGet 获取角色信息
func RoleGet(role string) error {
	res, err := cli.RoleGet(ctx, role)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// RoleDelete 删除角色
func RoleDelete(role string) error {
	res, err := cli.RoleDelete(ctx, role)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// RoleGrantPermission 赋予角色权限
func RoleGrantPermission(role string, key, rangeEnd string, permType clientv3.PermissionType) error {
	res, err := cli.RoleGrantPermission(ctx, role, key, rangeEnd, permType)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// RoleRevokePermission 撤销角色权限
func RoleRevokePermission(role string, key, rangeEnd string) error {
	res, err := cli.RoleRevokePermission(ctx, role, key, rangeEnd)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.5 user

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// UserList 获取用户列表
func UserList() error {
	res, err := cli.UserList(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserAdd 添加用户
func UserAdd(name, password string) error {
	res, err := cli.UserAdd(ctx, name, password)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserAddWithOptions 使用选项添加用户
func UserAddWithOptions(name, password string, options *clientv3.UserAddOptions) error {
	res, err := cli.UserAddWithOptions(ctx, name, password, options)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserChangePasswd 修改密码
func UserChangePasswd(name, password string) error {
	res, err := cli.UserChangePassword(ctx, name, password)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserGet 获取用户信息
func UserGet(name string) error {
	res, err := cli.UserGet(ctx, name)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserDelete 删除用户
func UserDelete(name string) error {
	res, err := cli.UserDelete(ctx, name)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserGrantRole 赋予用户角色
func UserGrantRole(name, role string) error {
	res, err := cli.UserGrantRole(ctx, name, role)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// UserRevokeRole 撤销用户角色
func UserRevokeRole(name, role string) error {
	res, err := cli.UserRevokeRole(ctx, name, role)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.6 lease

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// LeaseList 获取租约列表
func LeaseList() error {
	res, err := cli.Leases(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// LeaseGrant 生成租约
func LeaseGrant(ttl int64) error {
	res, err := cli.Grant(ctx, ttl)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// LeaseRevoke 撤销租约
func LeaseRevoke(id int64) error {
	res, err := cli.Revoke(ctx, clientv3.LeaseID(id))
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// LeaseTimeToLive 租约信息
func LeaseTimeToLive(id int64, opts ...clientv3.LeaseOption) error {
	res, err := cli.TimeToLive(ctx, clientv3.LeaseID(id), opts...)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// LeaseKeepAlive 保持租约不过期
func LeaseKeepAlive(id int64) error {
	res, err := cli.KeepAlive(ctx, clientv3.LeaseID(id))
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// LeaseKeepAliveOnce 更新租约一次
func LeaseKeepAliveOnce(id int64) error {
	res, err := cli.KeepAliveOnce(ctx, clientv3.LeaseID(id))
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.7 normal

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// Put 设置值
func Put(key, val string, opts ...clientv3.OpOption) error {
	res, err := cli.Put(ctx, key, val, opts...)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// Get 获取值
func Get(key string, opts ...clientv3.OpOption) error {
	res, err := cli.Get(ctx, key, opts...)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// Delete 删除键值对
func Delete(key string, opts ...clientv3.OpOption) error {
	res, err := cli.Delete(ctx, key, opts...)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// Watch 监听
func Watch(key string, opts ...clientv3.OpOption) {
	ch := cli.Watch(ctx, key, opts...)
	for v := range ch {
		for _, val := range v.Events {
			helper.PrintJSON(val)
		}
	}
}

2.8 txn

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// Txn 事务
func Txn(cmp []clientv3.Cmp, success []clientv3.Op, fail []clientv3.Op) error {
	txn := cli.Txn(ctx)
	for _,cs := range cmp {
		txn.If(cs)
	}
	for _,op := range success {
		txn.Then(op)
	}
	for _,op := range fail {
		txn.Else(op)
	}
	res, err := txn.Commit()
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

2.9 lock

package base

import (
	"go.etcd.io/etcd/client/v3/concurrency"
)

// Mutex 分布式锁
func Mutex(ttl int64, pfx string) (*concurrency.Mutex, error) {
	res, err := cli.Grant(ctx, ttl)
	if err != nil {
		return nil, err
	}
	s, err := concurrency.NewSession(
		cli, concurrency.WithContext(ctx), concurrency.WithTTL(int(ttl)), concurrency.WithLease(res.ID),
	)
	if err != nil {
		return nil, err
	}
	return concurrency.NewMutex(s, pfx), nil
}

2.10 snapshot

package base

import (
	clientv3 "go.etcd.io/etcd/client/v3"
	"go.etcd.io/etcd/client/v3/snapshot"
)

// SnapshotSave 生成快照
func SnapshotSave(cfg clientv3.Config, dbPath string) error {
	err := snapshot.Save(ctx, nil, cfg, dbPath)
	if err != nil {
		return err
	}
	return nil
}

2.11 alarm

package base

import (
	"github.com/jormin/etcd-demo/pkg/helper"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// AlarmList 获取警报列表
func AlarmList() error {
	res, err := cli.AlarmList(ctx)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}

// AlarmDisarm 解除警报
func AlarmDisarm(m *clientv3.AlarmMember) error {
	res, err := cli.AlarmDisarm(ctx, m)
	if err != nil {
		return err
	}
	helper.PrintJSON(res)
	return nil
}