Go语言微：启动Consul

╰+哭是因爲堅強的太久メ 2022-11-20 10:00 195阅读 0赞

## 启动Consul ##

安装配置好Consul以后，我们可以通过简单的命令启动consul。先来看最简单的启动方式：

consul agent -dev

在新终端中，执行如上操作。

![53dc2c47398326651b0a1e89d8350bcc.png][]

hongweiyu@localhost:~$ consul agent -dev
    ==> Starting Consul agent...
    ==> Consul agent running!
               Version: 'v1.5.1'
               Node ID: '808644da-c526-efa2-4f37-fff96168dcd1'
             Node name: 'localhost'
            Datacenter: 'dc1' (Segment: '<all>')
                Server: true (Bootstrap: false)
           Client Addr: [127.0.0.1] (HTTP: 8500, HTTPS: -1, gRPC: 8502, DNS: 8600)
          Cluster Addr: 127.0.0.1 (LAN: 8301, WAN: 8302)
               Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false
    
    ==> Log data will now stream in as it occurs:
    
        2019/06/17 15:36:18 [DEBUG] agent: Using random ID "808644da-c526-efa2-4f37-fff96168dcd1" as node ID
        2019/06/17 15:36:18 [DEBUG] tlsutil: Update with version 1
        2019/06/17 15:36:18 [DEBUG] tlsutil: OutgoingRPCWrapper with version 1
        2019/06/17 15:36:18 [DEBUG] tlsutil: IncomingRPCConfig with version 1
        2019/06/17 15:36:18 [DEBUG] tlsutil: OutgoingRPCWrapper with version 1
        2019/06/17 15:36:18 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:808644da-c526-efa2-4f37-fff96168dcd1 Address:127.0.0.1:8300}]
        2019/06/17 15:36:18 [INFO] raft: Node at 127.0.0.1:8300 [Follower] entering Follower state (Leader: "")
        2019/06/17 15:36:18 [INFO] serf: EventMemberJoin: localhost.dc1 127.0.0.1
        2019/06/17 15:36:18 [INFO] serf: EventMemberJoin: localhost 127.0.0.1
        2019/06/17 15:36:18 [INFO] consul: Handled member-join event for server "localhost.dc1" in area "wan"
        2019/06/17 15:36:18 [INFO] consul: Adding LAN server localhost (Addr: tcp/127.0.0.1:8300) (DC: dc1)
        2019/06/17 15:36:18 [DEBUG] agent/proxy: managed Connect proxy manager started
        2019/06/17 15:36:18 [INFO] agent: Started DNS server 127.0.0.1:8600 (tcp)
        2019/06/17 15:36:18 [INFO] agent: Started DNS server 127.0.0.1:8600 (udp)
        2019/06/17 15:36:18 [INFO] agent: Started HTTP server on 127.0.0.1:8500 (tcp)
        2019/06/17 15:36:18 [INFO] agent: started state syncer
        2019/06/17 15:36:18 [INFO] agent: Started gRPC server on 127.0.0.1:8502 (tcp)
        2019/06/17 15:36:18 [WARN] raft: Heartbeat timeout from "" reached, starting election
        2019/06/17 15:36:18 [INFO] raft: Node at 127.0.0.1:8300 [Candidate] entering Candidate state in term 2
        2019/06/17 15:36:18 [DEBUG] raft: Votes needed: 1
        2019/06/17 15:36:18 [DEBUG] raft: Vote granted from 808644da-c526-efa2-4f37-fff96168dcd1 in term 2. Tally: 1
        2019/06/17 15:36:18 [INFO] raft: Election won. Tally: 1
        2019/06/17 15:36:18 [INFO] raft: Node at 127.0.0.1:8300 [Leader] entering Leader state
        2019/06/17 15:36:18 [INFO] consul: cluster leadership acquired
        2019/06/17 15:36:18 [INFO] consul: New leader elected: localhost
        2019/06/17 15:36:18 [INFO] connect: initialized primary datacenter CA with provider "consul"
        2019/06/17 15:36:18 [DEBUG] consul: Skipping self join check for "localhost" since the cluster is too small
        2019/06/17 15:36:18 [INFO] consul: member 'localhost' joined, marking health alive
        2019/06/17 15:36:18 [DEBUG] agent: Skipping remote check "serfHealth" since it is managed automatically
        2019/06/17 15:36:18 [INFO] agent: Synced node info
        2019/06/17 15:36:18 [DEBUG] agent: Node info in sync
        2019/06/17 15:36:18 [DEBUG] agent: Skipping remote check "serfHealth" since it is managed automatically
        2019/06/17 15:36:18 [DEBUG] agent: Node info in sync
        2019/06/17 15:37:18 [DEBUG] consul: Skipping self join check for "localhost" since the cluster is too small
        2019/06/17 15:37:49 [DEBUG] agent: Skipping remote check "serfHealth" since it is managed automatically
        2019/06/17 15:37:49 [DEBUG] agent: Node info in sync
        2019/06/17 15:38:18 [DEBUG] manager: Rebalanced 1 servers, next active server is localhost.dc1 (Addr: tcp/127.0.0.1:8300) (DC: dc1)
        2019/06/17 15:38:18 [DEBUG] consul: Skipping self join check for "localhost" since the cluster is too small

上面贴出了Consul启动的输出日志，对日志做如下分析和说明：

*  \-dev：dev是consul多种启动模式的一种，dev是development的缩写，代表的是开发模式，该种启动模式仅仅是为了快速便捷的启动单节点consul，比如当前环境。
 *  Consul agent running!：表示该consul节点正常运行起来。
 *  Datacenter:'dc1' 表示当前节点所属的数据中心的名称为dc1。
 *  Server：true（bootstrap：false） 表示该节点属于Server角色。Consul节点统称为agent，有两类：Client、Server。
 *  raft: Heartbeat timeout from "" reached, starting election Raft算法开始进行Leader节点选举。
 *  consul: cluster leadership acquired、consul: New leader elected: localhost Leader节点选举结束，本地唯一的节点被选举为leader节点。
 *  consul: member 'localhost' joined, marking health alive 目前localhost节点是一个健康正常的节点

### 查看consul节点信息 ###

在consul启动后，可以通过命令查看节点的信息。在原有已经启动consul的终端窗口之外，重新开启新的终端窗口，执行如下命令：

consul members

![2abb7605aecaf463caf33df54eb7eb1f.png][]

Node       Address         Status  Type    Build  Protocol  DC   Segment
    localhost  127.0.0.1:8301  alive   server  1.5.1  2         dc1  <all>

输出日志说明： *Address：节点地址 *Status：alive表示节点健康运行 *Type：节点的类型，有两种：server、client *DC：Datacenter的缩写，dc1表示该节点属于Datacenter1

### UI界面访问 ###

终端命令行下启动consul的dev模式后，通过members命令查看节点信息，除此以外，还可以使用Http的浏览器访问的模式，查看节点信息。 consul启动，正常运行后，打开浏览器，在地址栏中键入：http://localhost:8500。可以查看节点信息，如下图：

![c6b3a40e2b1e6c76f628c9a7f17714fd.png][]

![fe2270e843c96a5d4d8197c56c21075e.png][]

### 停止服务 ###

在节点运行终端中执行：ctrl + c，表示退出节点运行。

![33595559b48b63ebb1b498b83e1719c7.png][]

2019/06/17 16:21:43 [INFO] agent: Caught signal:  interrupt
    2019/06/17 16:21:43 [INFO] agent: Graceful shutdown disabled. Exiting
    2019/06/17 16:21:43 [INFO] agent: Requesting shutdown
    2019/06/17 16:21:43 [WARN] agent: dev mode disabled persistence, killing all proxies since we can't recover them
    2019/06/17 16:21:43 [DEBUG] agent/proxy: Stopping managed Connect proxy manager
    2019/06/17 16:21:43 [INFO] consul: shutting down server
    2019/06/17 16:21:43 [WARN] serf: Shutdown without a Leave
    2019/06/17 16:21:43 [WARN] serf: Shutdown without a Leave
    2019/06/17 16:21:43 [INFO] manager: shutting down
    2019/06/17 16:21:43 [INFO] agent: consul server down
    2019/06/17 16:21:43 [INFO] agent: shutdown complete
    2019/06/17 16:21:43 [INFO] agent: Stopping DNS server 127.0.0.1:8600 (tcp)
    2019/06/17 16:21:43 [INFO] agent: Stopping DNS server 127.0.0.1:8600 (udp)
    2019/06/17 16:21:43 [INFO] agent: Stopping HTTP server 127.0.0.1:8500 (tcp)
    2019/06/17 16:21:43 [INFO] agent: Waiting for endpoints to shut down
    2019/06/17 16:21:43 [INFO] agent: Endpoints down
    2019/06/17 16:21:43 [INFO] agent: Exit code: 1

退出节点运行。

### consul dev模式示意图 ###

上诉consul agent -dev模式下的启动与运行consul节点。集群中只包含一个节点，唯一的节点被选举成为Leader节点。

![9eccfd2013a8616f60503999197a6873.png][]

[53dc2c47398326651b0a1e89d8350bcc.png]: /images/20221120/5458eb3522fb425cac1ac11fa2b2563f.png
[2abb7605aecaf463caf33df54eb7eb1f.png]: /images/20221120/ca3f7a3871264bbf814ec41bf84db3df.png
[c6b3a40e2b1e6c76f628c9a7f17714fd.png]: https://img-blog.csdnimg.cn/img_convert/c6b3a40e2b1e6c76f628c9a7f17714fd.png
[fe2270e843c96a5d4d8197c56c21075e.png]: https://img-blog.csdnimg.cn/img_convert/fe2270e843c96a5d4d8197c56c21075e.png
[33595559b48b63ebb1b498b83e1719c7.png]: https://img-blog.csdnimg.cn/img_convert/33595559b48b63ebb1b498b83e1719c7.png
[9eccfd2013a8616f60503999197a6873.png]: https://img-blog.csdnimg.cn/img_convert/9eccfd2013a8616f60503999197a6873.png