centos7下Etcd3集羣搭建

時間  2019-11-13
標籤 centos7 centos etcd3 etcd 集羣 搭建 欄目 Tomcat 简体版
原文   原文鏈接

1、環境介紹

etcd主要功能是分佈式的存儲鍵值，優勢很少說了，分佈是集羣，自動選舉等等，自行百度，主要說下配置方法，折騰了幾天，終於優勢眉目了，記錄下操做方法，本文參考了以下連接html

http://www.javashuo.com/article/p-fhxjkzzs-eh.html

http://www.361way.com/etcd-cluster/5468.html

https://n40lab.wordpress.com/2016/08/01/installing-coreos-etcd-server-on-centos-7/linux

 

建立了4個虛擬機，虛擬機中系統爲centos7（虛擬機使用的docker）git

for((i=1,i<5,i++))
do
 docker run -d --name etcd$i --hostname=etcd$i --privileged=true centos7 /usr/sbin/init
 docker exec -it etcd$i bash -c 「yum update -y&& yum install net-tools -y」
done


hostname    ip
etcd1 192.168.0.5
etcd2 192.168.0.6
etcd3 192.168.0.7
etcd4 192.168.0.8
將上述ip表添加到/etc/hosts中

2、etcd安裝與配置

2.1 yum安裝etcd

yum install etcd -ygithub

驗證etcd是否可用

# systemctl enable etcd&&systemctl start etcd
# etcdctl set hello world
world
# etcdctl get hello
world

這裏的集羣模式是指徹底集羣模式，固然也能夠在單機上經過不一樣的端口，部署僞集羣模式，只是那樣作只適合測試環境，生產環境考慮到可用性的話須要將etcd實例分佈到不一樣的主機上，這裏集羣搭建有三種方式，分佈是靜態配置，etcd發現，dns發現。默認配置運行etcd，監聽本地的2379端口，用於與client端交互，監聽2380用於etcd內部交互。etcd啓動時，集羣模式下會用到的參數以下：docker

  1. –name
  2. etcd集羣中的節點名，這裏能夠隨意，可區分且不重複就行
  3. –listen-peer-urls
  4. 監聽的用於節點之間通訊的url，可監聽多個，集羣內部將經過這些url進行數據交互(如選舉，數據同步等)
  5. –initial-advertise-peer-urls
  6. 建議用於節點之間通訊的url，節點間將以該值進行通訊。
  7. –listen-client-urls
  8. 監聽的用於客戶端通訊的url,一樣能夠監聽多個。
  9. –advertise-client-urls
  10. 建議使用的客戶端通訊url,該值用於etcd代理或etcd成員與etcd節點通訊。
  11. –initial-cluster-token etcd-cluster-1
  12. 節點的token值，設置該值後集羣將生成惟一id,併爲每一個節點也生成惟一id,當使用相同配置文件再啓動一個集羣時，只要該token值不同，etcd集羣就不會相互影響。
  13. –initial-cluster
  14. 也就是集羣中全部的initial-advertise-peer-urls 的合集
  15. –initial-cluster-state new
  16. 新建集羣的標誌，初始化狀態使用 new，創建以後改此值爲 existing

yum安裝etcd須要修改兩個配置文件

# vim /lib/systemd/system/etcd.service
[Unit]
Description=Etcd Server
After=network.target
After=network-online.target
Wants=network-online.target

[Service]
Type=notify
WorkingDirectory=/var/lib/etcd/
EnvironmentFile=-/etc/etcd/etcd.conf
User=etcd
# set GOMAXPROCS to number of processors
ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /usr/bin/etcd \
--name=\"${ETCD_NAME}\" \
--data-dir=\"${ETCD_DATA_DIR}\" \
--listen-peer-urls=\"${ETCD_LISTEN_PEER_URLS}\" \
--advertise-client-urls=\"${ETCD_ADVERTISE_CLIENT_URLS}\" \
--initial-cluster-token=\"${ETCD_INITIAL_CLUSTER_TOKEN}\" \
--initial-cluster=\"${ETCD_INITIAL_CLUSTER}\"  \
--initial-cluster-state=\"${ETCD_INITIAL_CLUSTER_STATE}\" \
--listen-client-urls=\"${ETCD_LISTEN_CLIENT_URLS}\""
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

# vim /etc/etcd/etcd.conf
ETCD_NAME=etcd1
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://etcd1:2380"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd02=http://etcd2:2380,etcd03=http://etcd3:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd1:2379"

 

配置好3臺虛擬機以後同時啓動etcd服務

# systemctl start etcd

正常狀況能夠查看到成員列表etcdctl member listvim

# etcdctl member list
3b05c2e4e4c104b4: name=etcd1 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd2 peerURLs=http://etcd2:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd3 peerURLs=http://etcd3:2380 clientURLs=http://etcd2:2379 isLeader=false


2.2 二進制包安裝etcd

yum雖然也能用，仍是二進制包的方法操做簡單些。centos

下載穩定版本的etcd二進制包安全

mkdir /var/lib/etcd;mkdir /etc/etcd; groupadd -r etcd; useradd -r -g etcd -d /var/lib/etcd -s /sbin/nologin -c "etcd user" etcd;chown -R etcd:etcd /var/lib/etcd

ETCD_VERSION=`curl -s -L https://github.com/coreos/etcd/releases/latest | grep linux-amd64\.tar\.gz | grep href | cut -f 6 -d '/' | sort -u`; ETCD_DIR=/opt/etcd-$ETCD_VERSION; mkdir $ETCD_DIR;curl -L https://github.com/coreos/etcd/releases/download/$ETCD_VERSION/etcd-$ETCD_VERSION-linux-amd64.tar.gz | tar xz --strip-components=1 -C $ETCD_DIR; ln -sf $ETCD_DIR/etcd /usr/bin/etcd && ln -sf $ETCD_DIR/etcdctl /usr/bin/etcdctl; etcd --version

四臺虛擬機新建etcd服務啓動腳本bash

[root@etcd1 /]# vim /lib/systemd/system/etcd.service
[Unit]
Description=etcd service
After=network.target

[Service]
Type=notify
WorkingDirectory=/var/lib/etcd/
EnvironmentFile=-/etc/etcd/etcd.conf
User=etcd
ExecStart=/usr/bin/etcd
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

etcd靜態模式集羣配置（即知道須要哪幾臺虛擬機須要創建集羣）etcd1，etcd2與etcd3創建集羣后etcd4加入集羣。
修改etcd1配置文件
[root@etcd1 /]# cat /etc/etcd/etcd.conf
ETCD_NAME=etcd1
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://etcd1:2380"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd02=http://etcd2:2380,etcd03=http://etcd3:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd1:2379"

修改etcd2配置文件
[root@etcd2 /]# cat /etc/etcd/etcd.conf
ETCD_NAME=etcd2
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://etcd2:2380"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd02=http://etcd2:2380,etcd03=http://etcd3:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd2:2379"

修改etcd3配置文件
[root@etcd3 /]# cat /etc/etcd/etcd.conf
ETCD_NAME=etcd3
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://etcd3:2380"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd02=http://etcd2:2380,etcd03=http://etcd3:2380"
ETCD_INITIAL_CLUSTER_STATE="new"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd3:2379"

配置好3臺虛擬機以後同時啓動etcd服務

# systemctl start etcd

正常狀況能夠查看到成員列表etcdctl member list服務器

[root@etcd1 /]# etcdctl member list
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false

etcd配置過程當中遇到的問題，添加節點，刪除節點，備份數據
### 本地鏈接報錯
[root@etcd2 /]# etcdctl member list
Error:  client: etcd cluster is unavailable or misconfigured; error #0: dial tcp 127.0.0.1:2379: getsockopt: connection refused
; error #1: dial tcp 127.0.0.1:4001: getsockopt: connection refused

error #0: dial tcp 127.0.0.1:2379: getsockopt: connection refused
error #1: dial tcp 127.0.0.1:4001: getsockopt: connection refused

若是出現如上的錯誤，是由於ETCD_LISTEN_CLIENT_URLS參數沒有配置http://127.0.0.1:2379而致使的，因此這裏我使用了0.0.0.0表明了監控全部地址。
除此以外仍上述報錯，當配置的很混亂的時候能夠刪掉/var/lib/etcd/中的default.etcd文件,前提是數據不重要哈。還要注意default.etcd文件夾權限改成etcd：etcd

chown -R etcd:etcd default.etcd此步很重要，另外還須要細心檢查/etc/etcd/etcd.conf和/lib/systemd/system/etcd.service是否有錯誤。改完以後再重啓etcd服務（systemctl start etcd）就ok了。

etcd集羣中添加一節點etcd04

在現有集羣etcd三臺虛擬機中任何一臺操做添加新節點etcd04

[root@etcd1 /]# etcdctl member list
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false
[root@etcd1 /]# etcdctl member add etcd04 http://etcd4:2380
Added member named etcd04 with ID ec8c708bb5b2fdc6 to cluster

ETCD_NAME="etcd04"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd03=http://etcd3:2380,etcd02=http://etcd2:2380,etcd04=http://etcd4:2380"
ETCD_INITIAL_CLUSTER_STATE="existing"   
注意此處三條必需要與etcd04配置文件（/etc/etcd/etcd.conf）相符合
[root@etcd1 /]# etcdctl member list
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false
ec8c708bb5b2fdc6[unstarted]: peerURLs=http://etcd4:2380

啓動etcd服務以前修改etcd04配置文件
[root@etcd4 /]# vim /etc/etcd/etcd.conf
ETCD_NAME=etcd04
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
ETCD_LISTEN_PEER_URLS="http://0.0.0.0:2380"
ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
ETCD_INITIAL_ADVERTISE_PEER_URLS="http://etcd4:2380"
ETCD_INITIAL_CLUSTER="etcd01=http://etcd1:2380,etcd02=http://etcd2:2380,etcd03=http://etcd3:2380,etcd04=http://etcd4:2380"
ETCD_INITIAL_CLUSTER_STATE="existing"
ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://etcd4:2379"

若是/var/lib/etcd/中存在default.etcd必定要刪除，否側etcd服務啓動失敗（由於集羣中給etcd04分配的物理id與現有庫中的id不相同）

[root@etcd4 /]# rm -rf /var/lib/etcd/default.etcd/
[root@etcd4 /]# systemctl start etcd        
[root@etcd4 /]# etcdctl member list         #啓動服務後再查詢etcd04已加入集羣中
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false
ec8c708bb5b2fdc6: name=etcd04 peerURLs=http://etcd4:2380 clientURLs=http://etcd4:2379 isLeader=false

etcd集羣中刪除etcd04節點

現有集羣節點是4個

[root@etcd1 /]# etcdctl member list
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
b28ea7a9615a2c72: name=etcd04 peerURLs=http://etcd4:2380 clientURLs=http://etcd4:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false

在除etcd04節點外的任意一臺中操做刪除etcd04節點
[root@etcd1 /]# etcdctl member remove b28ea7a9615a2c72
Removed member b28ea7a9615a2c72 from cluster
[root@etcd1 /]# etcdctl member list
3b05c2e4e4c104b4: name=etcd01 peerURLs=http://etcd1:2380 clientURLs=http://etcd1:2379 isLeader=false
bd388e7810915853: name=etcd03 peerURLs=http://etcd3:2380 clientURLs=http://etcd3:2379 isLeader=true
d282ac2ce600c1ce: name=etcd02 peerURLs=http://etcd2:2380 clientURLs=http://etcd2:2379 isLeader=false

etcd集羣中備份數據

etcd的數據應該算是很安全的，即使出現單點故障，數據也不會丟失，前提是節點不在同一臺服務器中
etcd的數據備份比較。。。網上的方法
etcdctl backup --data-dir /var/lib/etcd/default.etcd/ --backup-dir /home/etcd_backup
備份完以後，發現沒有db文件，好尷尬啊，全部我直接cp了，
cp -r /var/lib/etcd/default.etcd/ /home/etcd_backup

chown -R etcd:etcd default.etcd嗯，就能夠了。

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