etcd创建集群并增加节点

下载安装

• 从这下载https://github.com/coreos/etcd/releases/download/v3.3.2/etcd-v3.3.2-linux-amd64.tar.gz
• tar xzvf etcd-v3.3.2-linux-amd64.tar.gz
• cd etcd-v3.3.2-linux-amd64; cp etcd* /user/local/bin/
• 这样即成功添加etcd命令
  etcd –version

运行与搭建

常见命令演示

etcd –version
etcdctl –version

API3的要这样
ETCDCTL_API=3 etcdctl version

启动：etcd
写一个数据与读取一个数据：key:key1 value:helloworld
ETCDCTL_API=3 etcdctl –endpoints=localhost:2379 put helloworld
ETCDCTL_API=3 etcdctl –endpoints=localhost:2379 get key1

单机启动：

etcd --name myetcd1  --listen-client-urls http://0.0.0.0:2379 --advertise-client-urls http://0.0.0.0:2379 --listen-peer-urls http://0.0.0.0:2380 --initial-advertise-peer-urls http://0.0.0.0:2380  --initial-cluster my-etcd-1=http://0.0.0.0:2380

集群启动：

mkdir /var/lib/etcd-{01..04}

etcd --name myetcd1  --listen-client-urls http://0.0.0.0:2379 --data-dir=/var/lib/etcd-01 --advertise-client-urls http://192.168.9.100:2379 --listen-peer-urls http://0.0.0.0:2380 --initial-advertise-peer-urls http://192.168.9.100:2380  --initial-cluster-token etcd-cluster-test --initial-cluster-state new --initial-cluster myetcd1=http://192.168.9.100:2380,myetcd2=http://192.168.9.100:2381,myetcd3=http://192.168.9.100:2382 >>/tmp/etcd01.log 2>&1 &

etcd --name myetcd2  --listen-client-urls http://0.0.0.0:2389 --data-dir=/var/lib/etcd-02 --advertise-client-urls http://192.168.9.100:2389 --listen-peer-urls http://0.0.0.0:2381 --initial-advertise-peer-urls http://192.168.9.100:2381  --initial-cluster-token etcd-cluster-test --initial-cluster-state new --initial-cluster myetcd1=http://192.168.9.100:2380,myetcd2=http://192.168.9.100:2381,myetcd3=http://192.168.9.100:2382 >>/tmp/etcd02.log 2>&1 &

etcd --name myetcd3  --listen-client-urls http://0.0.0.0:2399 --data-dir=/var/lib/etcd-03 --advertise-client-urls http://192.168.9.100:2399 --listen-peer-urls http://0.0.0.0:2382 --initial-advertise-peer-urls http://192.168.9.100:2382  --initial-cluster-token etcd-cluster-test --initial-cluster-state new --initial-cluster myetcd1=http://192.168.9.100:2380,myetcd2=http://192.168.9.100:2381,myetcd3=http://192.168.9.100:2382 >>/tmp/etcd03.log 2>&1 &

用三个端口2380,2381,2382来模拟集群(这三个是成员之间通信),2379,2389,2399是给客户端连接的.服务器IP：192.168.9.100, 如果在本机模拟集群, 可以将192.168.9.100改为0.0.0.0

带advertise参数是广播参数: 如–listen-client-urls和–advertise-client-urls, 前者是Etcd端监听客户端的url,后者是Etcd客户端请求的url, 两者端口是相同的, 只不过后者一般为公网IP, 暴露给外部使用.

查看成员:

etcdctl member list 

使用时需要指定endpoints(默认本地端口2379), 集群时数据会迅速同步:

ETCDCTL_API=3 etcdctl –endpoints=127.0.0.1:2389 put key1 xx 
ETCDCTL_API=3 etcdctl –endpoints=127.0.0.1:2379 get key1

参数说明

–name etcd0：本member的名字

–initial-advertise-peer-urls http://192.168.9.100:2380： 其他member使用，其他member通过该地址与本member交互信息。一定要保证从其他member能可访问该地址。静态配置方式下，该参数的value一定要同时在–initial-cluster参数中存在。memberID的生成受–initial-cluster-token和–initial-advertise-peer-urls影响。

–listen-peer-urls http://0.0.0.0:2380：本member侧使用，用于监听其他member发送信息的地址。ip为全0代表监听本member侧所有接口

–listen-client-urls http://0.0.0.0:2379： 本member侧使用，用于监听etcd客户发送信息的地址。ip为全0代表监听本member侧所有接口

–advertise-client-urls http://192.168.9.100:2379： etcd客户使用，客户通过该地址与本member交互信息。一定要保证从客户侧能可访问该地址

–initial-cluster-token etcd-cluster-2：用于区分不同集群。本地如有多个集群要设为不同。

–initial-cluster myetcd0=http://192.168.9.100:2380,myetcd1=http://192.168.9.100:2381,myetcd2=http://192.168.9.100:2382：本member侧使用。描述集群中所有节点的信息，本member根据此信息去联系其他member。memberID的生成受–initial-cluster-token和–initial-advertise-peer-urls影响。

–initial-cluster-state new：用于指示本次是否为新建集群。有两个取值new和existing。如果填为existing，则该member启动时会尝试与其他member交互。集群初次建立时，要填为new，经尝试最后一个节点填existing也正常，其他节点不能填为existing。集群运行过程中，一个member故障后恢复时填为existing，经尝试填为new也正常。

–data-dir：指定节点的数据存储目录，这些数据包括节点ID，集群ID，集群初始化配置，Snapshot文件，若未指定-wal-dir，还会存储WAL文件；如果不指定会用缺省目录。

–discovery http://192.168.9.100:20003/v2/keys/discovery/78b12ad7-2c1d-40db-9416-3727baf686cb：用于自发现模式下，指定第三方etcd上key地址，要建立的集群各member都会向其注册自己的地址。

　　

使用详细说明

ETCD API有两种, 一种是3, 一种是2, 默认为2, 我们主要用3:

API3:

[root@guods-1 centos]# ETCDCTL_API=3 etcdctl --endpoints=localhost:2379 put key1 helloworld
OK
[root@guods-1 centos]# ETCDCTL_API=3 etcdctl --endpoints=localhost:2379 get key1
key1
helloworld

API2:

[root@guods-1 centos]# etcdctl set key2 helloworld
helloworld
[root@guods-1 centos]# etcdctl get key2
helloworld
命令详解：

[root@guods-1 centos]# ETCDCTL_API=2 etcdctl
NAME:
   etcdctl - A simple command line client for etcd.

USAGE:
   etcdctl [global options] command [command options] [arguments...]

VERSION:
   3.3.2

COMMANDS:
     backup          backup an etcd directory
     cluster-health  check the health of the etcd cluster
     mk              make a new key with a given value
     mkdir           make a new directory
     rm              remove a key or a directory
     rmdir           removes the key if it is an empty directory or a key-value pair
     get             retrieve the value of a key
     ls              retrieve a directory
     set             set the value of a key
     setdir          create a new directory or update an existing directory TTL
     update          update an existing key with a given value
     updatedir       update an existing directory
     watch           watch a key for changes
     exec-watch      watch a key for changes and exec an executable
     member          member add, remove and list subcommands
     user            user add, grant and revoke subcommands
     role            role add, grant and revoke subcommands
     auth            overall auth controls
     help, h         Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --debug                          output cURL commands which can be used to reproduce the request
   --no-sync                        don't synchronize cluster information before sending request
   --output simple, -o simple       output response in the given format (simple, `extended` or `json`) (default: "simple")
   --discovery-srv value, -D value  domain name to query for SRV records describing cluster endpoints
   --insecure-discovery             accept insecure SRV records describing cluster endpoints
   --peers value, -C value          DEPRECATED - "--endpoints" should be used instead
   --endpoint value                 DEPRECATED - "--endpoints" should be used instead
   --endpoints value                a comma-delimited list of machine addresses in the cluster (default: "http://127.0.0.1:2379,http://127.0.0.1:4001")
   --cert-file value                identify HTTPS client using this SSL certificate file
   --key-file value                 identify HTTPS client using this SSL key file
   --ca-file value                  verify certificates of HTTPS-enabled servers using this CA bundle
   --username value, -u value       provide username[:password] and prompt if password is not supplied.
   --timeout value                  connection timeout per request (default: 2s)
   --total-timeout value            timeout for the command execution (except watch) (default: 5s)
   --help, -h                       show help
   --version, -v                    print the version

　　

[root@guods-1 centos]# ETCDCTL_API=3 etcdctl

NAME:
    etcdctl - A simple command line client for etcd3.

USAGE:
    etcdctl

VERSION:
    3.3.2

API VERSION:
    3.3


COMMANDS:
    get         Gets the key or a range of keys
    put         Puts the given key into the store
    del         Removes the specified key or range of keys [key, range_end)
    txn         Txn processes all the requests in one transaction
    compaction      Compacts the event history in etcd
    alarm disarm        Disarms all alarms
    alarm list      Lists all alarms
    defrag          Defragments the storage of the etcd members with given endpoints
    endpoint health     Checks the healthiness of endpoints specified in `--endpoints` flag
    endpoint status     Prints out the status of endpoints specified in `--endpoints` flag
    endpoint hashkv     Prints the KV history hash for each endpoint in --endpoints
    move-leader     Transfers leadership to another etcd cluster member.
    watch           Watches events stream on keys or prefixes
    version         Prints the version of etcdctl
    lease grant     Creates leases
    lease revoke        Revokes leases
    lease timetolive    Get lease information
    lease list      List all active leases
    lease keep-alive    Keeps leases alive (renew)
    member add      Adds a member into the cluster
    member remove       Removes a member from the cluster
    member update       Updates a member in the cluster
    member list     Lists all members in the cluster
    snapshot save       Stores an etcd node backend snapshot to a given file
    snapshot restore    Restores an etcd member snapshot to an etcd directory
    snapshot status     Gets backend snapshot status of a given file
    make-mirror     Makes a mirror at the destination etcd cluster
    migrate         Migrates keys in a v2 store to a mvcc store
    lock            Acquires a named lock
    elect           Observes and participates in leader election
    auth enable     Enables authentication
    auth disable        Disables authentication
    user add        Adds a new user
    user delete     Deletes a user
    user get        Gets detailed information of a user
    user list       Lists all users
    user passwd     Changes password of user
    user grant-role     Grants a role to a user
    user revoke-role    Revokes a role from a user
    role add        Adds a new role
    role delete     Deletes a role
    role get        Gets detailed information of a role
    role list       Lists all roles
    role grant-permission   Grants a key to a role
    role revoke-permission  Revokes a key from a role
    check perf      Check the performance of the etcd cluster
    help            Help about any command

OPTIONS:
      --cacert=""               verify certificates of TLS-enabled secure servers using this CA bundle
      --cert=""                 identify secure client using this TLS certificate file
      --command-timeout=5s          timeout for short running command (excluding dial timeout)
      --debug[=false]               enable client-side debug logging
      --dial-timeout=2s             dial timeout for client connections
  -d, --discovery-srv=""            domain name to query for SRV records describing cluster endpoints
      --endpoints=[127.0.0.1:2379]      gRPC endpoints
  -h, --help[=false]                help for etcdctl
      --hex[=false]             print byte strings as hex encoded strings
      --insecure-discovery[=true]       accept insecure SRV records describing cluster endpoints
      --insecure-skip-tls-verify[=false]    skip server certificate verification
      --insecure-transport[=true]       disable transport security for client connections
      --keepalive-time=2s           keepalive time for client connections
      --keepalive-timeout=6s            keepalive timeout for client connections
      --key=""                  identify secure client using this TLS key file
      --user=""                 username[:password] for authentication (prompt if password is not supplied)
  -w, --write-out="simple"          set the output format (fields, json, protobuf, simple, table)

　　

主要两步：

• 添加节点
• 启动新节点

原本etcd集群

# etcdctl member list
b7124c8d88451: name=myetcd1 peerURLs=http://192.168.9.100:2380 clientURLs=http://192.168.9.100:2379 isLeader=true
235dcf74ed6248d5: name=myetcd3 peerURLs=http://192.168.9.100:2382 clientURLs=http://192.168.9.100:2399 isLeader=false
e35665335259ca10: name=myetcd2 peerURLs=http://192.168.9.100:2381 clientURLs=http://192.168.9.100:2389 isLeader=false

新增节点： 192.168.9.101：2383

必须先设置export ETCDCTL_API=2

# etcdctl member add myetcd4  http://192.168.9.101:2383

Added member named myetcd4 with ID 2644935c1a10c721 to cluster

ETCD_NAME="myetcd4"
ETCD_INITIAL_CLUSTER="myetcd1=http://192.168.9.100:2380,myetcd3=http://192.168.9.100:2382,myetcd4=http://192.168.9.101:2383,myetcd2=http://192.168.9.100:2381"
ETCD_INITIAL_CLUSTER_STATE="existing"

启动新节点：（设置export ETCDCTL_API=3）

# etcd --name myetcd4  --listen-client-urls http://0.0.0.0:2409 --data-dir=/var/lib/etcd-04 --advertise-client-urls http://192.168.9.101:2409 --listen-peer-urls http://0.0.0.0:2383 --initial-advertise-peer-urls http://192.168.9.101:2383  --initial-cluster-token etcd-cluster-test --initial-cluster-state existing --initial-cluster myetcd1=http://192.168.9.100:2380,myetcd2=http://192.168.9.100:2381,myetcd3=http://192.168.9.100:2382,myetcd4=http://192.168.9.101:2383 >>/tmp/etcd04.log 2>&1 &