ETCD 单机安装

由于测试的需要，有时需要搭建一个单机版的etcd 环境，为了方便以后搭建查看，现在对单机部署进行记录。

一、部署单机etcd

下载指定版本的etcd
下载地址

ftp://ftp.pbone.net/mirror/archive.fedoraproject.org/fedora/linux/updates/22/x86_64/e/etcd-2.2.5-1.fc22.x86_64.rpm

先判断是否已经安装了etcd，已经安装的话就需要先删除掉，注意权限问题

[vagrant@localhost wae]$ yum list installed | grep etcd

etcd.x86_64                      2.2.-.el7                  installed

[vagrant@localhost wae]$ yum remove etcd.x86_64

Loaded plugins: fastestmirror

You need to be root to perform this command.

[vagrant@localhost wae]$ sudo  yum remove etcd.x86_64

Loaded plugins: fastestmirror

Resolving Dependencies

--> Running transaction check

---> Package etcd.x86_64 :2.2.-.el7 will be erased

--> Finished Dependency Resolution

Dependencies Resolved

===================================================================================================

 Package            Arch                 Version                     Repository               Size

===================================================================================================

Removing:

 etcd               x86_64               2.2.-.el7                 installed                 M

Transaction Summary

===================================================================================================

Remove   Package

Installed size:  M

Is this ok [y/N]: y

Downloading packages:

Running transaction check

Running transaction test

Transaction test succeeded

Running transaction

  Erasing    : etcd-2.2.-.el7.x86_64                                                         /

warning: /etc/etcd/etcd.conf saved as /etc/etcd/etcd.conf.rpmsave

  Verifying  : etcd-2.2.-.el7.x86_64                                                         / 

Removed:

  etcd.x86_64 :2.2.-.el7                                                                        

Complete!

安装下载的rpm包

[vagrant@localhost etcd]$ sudo yum localinstall etcd-2.2.-.fc22.x86_64.rpm

验证安装成功

[vagrant@localhost etcd]$ etcdctl --version

etcdctl version 2.2.

创建一个服务描述文件，放入systemd的服务目录下，一般安装完成都会自动创建

[vagrant@localhost etcd]$ sudo vi /usr/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=\"${ETCD_DATA_DIR}\" --listen-client-urls=\"${ETCD_LISTEN_CLIENT_URLS}\""

Restart=on-failure

LimitNOFILE=

[Install]

WantedBy=multi-user.target

修改etcd的配置
一般默认访问的地址是http://localhost:2379，这边我们可以自定义，因为是单机，我们就直接127.0.0.1，有想法的就端口修改下好了
```
[vagrant@localhost etcd]$ sudo vi /etc/etcd/etcd.conf
```
# [member]
ETCD_NAME=default
ETCD_DATA_DIR="/var/lib/etcd/default.etcd"
#ETCD_WAL_DIR=""
#ETCD_SNAPSHOT_COUNT="10000"
#ETCD_HEARTBEAT_INTERVAL="100"
#ETCD_ELECTION_TIMEOUT="1000"
#ETCD_LISTEN_PEER_URLS="http://localhost:2380"
ETCD_LISTEN_CLIENT_URLS="http://127.0.0.1:4001"
#ETCD_MAX_SNAPSHOTS="5"
#ETCD_MAX_WALS="5"
#ETCD_CORS=""
#
#[cluster]
#ETCD_INITIAL_ADVERTISE_PEER_URLS="http://localhost:2380"
# if you use different ETCD_NAME (e.g. test), set ETCD_INITIAL_CLUSTER value for this name, i.e. "test=http://..."
#ETCD_INITIAL_CLUSTER="default=http://localhost:2380"
#ETCD_INITIAL_CLUSTER_STATE="new"
#ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster"
ETCD_ADVERTISE_CLIENT_URLS="http://127.0.0.1:4001"
#ETCD_DISCOVERY=""
#ETCD_DISCOVERY_SRV=""
#ETCD_DISCOVERY_FALLBACK="proxy"
#ETCD_DISCOVERY_PROXY=""
#
#[proxy]
#ETCD_PROXY="off"
#ETCD_PROXY_FAILURE_WAIT="5000"
#ETCD_PROXY_REFRESH_INTERVAL="30000"
#ETCD_PROXY_DIAL_TIMEOUT="1000"
#ETCD_PROXY_WRITE_TIMEOUT="5000"
#ETCD_PROXY_READ_TIMEOUT="0"
#
#[security]
#ETCD_CERT_FILE=""
#ETCD_KEY_FILE=""
#ETCD_CLIENT_CERT_AUTH="false"
#ETCD_TRUSTED_CA_FILE=""
#ETCD_PEER_CERT_FILE=""
#ETCD_PEER_KEY_FILE=""
#ETCD_PEER_CLIENT_CERT_AUTH="false"
#ETCD_PEER_TRUSTED_CA_FILE=""
#
#[logging]
#ETCD_DEBUG="false"
# examples for -log-package-levels etcdserver=WARNING,security=DEBUG
#ETCD_LOG_PACKAGE_LEVELS=""
如果想要局域网可以访问的话，则将 127.0.0.1 换成宿主机的 ip 即可了，最后外部用 ip 进行接口访问即可。

启动并测试ETCD
首先设置开机启动：systemctl enable etcd

[vagrant@localhost etcd]$ sudo systemctl daemon-reload

[vagrant@localhost etcd]$ sudo systemctl start etcd

[vagrant@localhost etcd]$ sudo  systemctl status etcd

● etcd.service - Etcd Server

   Loaded: loaded (/usr/lib/systemd/system/etcd.service; disabled; vendor preset: disabled)

   Active: active (running) since Fri -- :: UTC; 8s ago

 Main PID:  (etcd)

   Memory: 26.0M

   CGroup: /system.slice/etcd.service

           └─ /usr/bin/etcd --name=default --data-dir=/var/lib/etcd/default.etcd --listen-cl...

Mar  :: localhost.localdomain systemd[]: Starting Etcd Server...

Mar  :: localhost.localdomain systemd[]: Started Etcd Server.

查看集群健康状态

[vagrant@localhost etcd]$ sudo etcdctl cluster-health

member ce2a822cea30bfca is healthy: got healthy result from http://127.0.0.1:4001

cluster is healthy

ok，没有问题

卸载与删除etcd

[vagrant@localhost wae]$ yum list installed | grep etcd

etcd.x86_64                      2.2.-.el7                  installed

[vagrant@localhost wae]$ yum remove etcd.x86_64

二、接口测试

etcd的数据形式是以健对值方式存在的。

通过接口获取版本信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/version -XGET

{"etcdserver":"2.2.5","etcdcluster":"2.2.0"}

更新一个健对值信息，并通过 ke y获取到 value

[vagrant@localhost etcd]$ etcdctl set /tmp/message wozainali

wozainali

[vagrant@localhost etcd]$ etcdctl get /tmp/message

wozainali

设置的方式：etcdctl set key value
获取的方式：etcdctl get key

通过接口获取健对值信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XGET

{"action":"get","node":{"key":"/tmp/message","value":"wozainali","modifiedIndex":,"createdIndex":}}

再看看详细的请求信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XGET

{"action":"get","node":{"key":"/tmp/message","value":"wozainali","modifiedIndex":,"createdIndex":}}

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XGET -vv

* About to connect() to 127.0.0.1 port  (#)

*   Trying 127.0.0.1...

* Connected to 127.0.0.1 (127.0.0.1) port  (#)

> GET /v2/keys/tmp/message HTTP/1.1

> User-Agent: curl/7.29.

> Host: 127.0.0.1:

> Accept: */*

>

< HTTP/1.1 200 OK

< Content-Type: application/json

< X-Etcd-Cluster-Id: 7e27652122e8b2ae

< X-Etcd-Index: 12

< X-Raft-Index: 37173

< X-Raft-Term: 3

< Date: Fri, 09 Mar 2018 09:16:15 GMT

< Content-Length: 104

<

{"action":"get","node":{"key":"/tmp/message","value":"wozainali","modifiedIndex":12,"createdIndex":12}}

* Connection #0 to host 127.0.0.1 left intact

通过接口更新一个健对值信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XPUT -d value=nihaoha

{"action":"set","node":{"key":"/tmp/message","value":"nihaoha","modifiedIndex":,"createdIndex":},"prevNode":{"key":"/tmp/message","value":"wozainali","modifiedIndex":,"createdIndex":}}

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XGET

{"action":"get","node":{"key":"/tmp/message","value":"nihaoha","modifiedIndex":,"createdIndex":}}

我们看到更新的时候，会有两条记录，一条是当前记录，一条是之前的记录，多次更新也只会保留最近的信息，获取的时候默认获取最新的信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XPUT -d value=wowowow

{"action":"set","node":{"key":"/tmp/message","value":"wowowow","modifiedIndex":,"createdIndex":},"prevNode":{"key":"/tmp/message","value":"nihaoha","modifiedIndex":,"createdIndex":}}

具体复杂的操作需要去看官方文档，这边只做了解使用。https://coreos.com/etcd/docs/latest/v2/api.html

通过接口删除健对值信息

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XDELETE

{"action":"delete","node":{"key":"/tmp/message","modifiedIndex":,"createdIndex":},"prevNode":{"key":"/tmp/message","value":"wowowow","modifiedIndex":,"createdIndex":}}

[vagrant@localhost etcd]$ curl http://127.0.0.1:4001/v2/keys/tmp/message -XGET

{"errorCode":,"message":"Key not found","cause":"/tmp/message","index":}

可以看到删除之后，重新去获取该 key 的值，提示Key not found，证明我们删除成功了。

以上就是，简单的指定etcd单机安装，以及api的几个简单应用。

三、问题

在修改访问ip问局域网ip之后发现，使用 etcdctl 进行操作的时候会出现如下错误

[vagrant@localhost etcd]$ etcdctl ls

Error:  dial tcp 127.0.0.1:: getsockopt: connection refused

[vagrant@localhost etcd]$

[vagrant@localhost etcd]$

[vagrant@localhost etcd]$ etcdctl cluster-health

cluster may be unhealthy: failed to list members

Error:  client: etcd cluster is unavailable or misconfigured

error #: dial tcp 127.0.0.1:: getsockopt: connection refused

error #: dial tcp 127.0.0.1:: getsockopt: connection refused

查询之后，发现应该是 ETCD_LISTEN_CLIENT_URLS 没有写入 http://127.0.0.1:4001 的原因，追加配置 http://127.0.0.1:4001，重新试一下

[vagrant@localhost etcd]$ etcdctl ls

/test

/test123

/tmp

/test1223

[vagrant@localhost etcd]$ etcdctl cluster-health

member ce2a822cea30bfca is healthy: got healthy result from http://192.168.10.50:4001

cluster is healthy

[vagrant@localhost etcd]$

现在就可以了。
注意，添加配置的时候，用英文的逗号隔开.