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.NET Core微服务之路:基于Consul最少集群实现服务的注册与发现(一)

Consul介绍

  Consul是HashiCorp公司推出的开源工具[开源地址:https://github.com/hashicorp/consul],用于实现分布式系统的服务发现与配置。
 
  与市面上其他系统比较如下:
 
  总体而言, Consul用Golang实现,因此具有天然可移植性(支持Linux、windows和Mac OS X);安装包仅包含一个可执行文件,方便部署,与Docker等轻量级容器可无缝配合
此外,关于Consul的架构以及相关的角色,如下图所示:
  以Server模式运行的Consul Agent节点用于维护Consul集群的状态,官方建议每个Consul Cluster至少有3个或以上的运行在Server Mode的Agent,Client节点不限。Consul支持多数据中心,每个数据中心的Consul Cluster都会在运行于Server模式下的Agent节点中选出一个Leader节点,这个选举过程通过Consul实现的raft协议保证,多个 Server节点上的Consul数据信息是强一致的。处于Client Mode的Consul Agent节点比较简单,无状态,仅仅负责将请求转发给Server Agent节点。
 

集群搭建

  笔者打算通过五台Centos7来搭建Consul集群,借助VMware Workstation搭建,当然,最主要的是这台虚拟主机一定要相互ping通,最好关闭防火墙,而且,虚拟机也需要和宿主机(实比如笔者的Windows10操作系统)ping通,具体问题和配置可搜索一下,图片如下:

 

  其中130作为leader角色,129和131作为follower角色,当然,在实际环境中,leader的角色不一定是固定的,会随着环境变化而变化(比如网络断了、宕机了等等)这个我们后续来验证。132和133作为客户端,并安装NET Core 2.1环境,再次提示,一定要保证在这个环境中的所有系统相互之间均能Ping通。

 

step1:关闭防火墙

systemctl stop firewalld
systemctl disable firewalld

 

step2:安装consul

wget https://releases.hashicorp.com/consul/1.3.0/consul_1.3.0_linux_amd64.zip
unzip consul_1.3.0_linux_amd64.zip

 

step3:节点1

./consul agent -server -ui -bootstrap-expect=3 -data-dir=/tmp/consul -node=consul-1 -client=0.0.0.0 -bind=192.168.153.129 -datacenter=dc1 #设置129为服务器
bootstrap_expect > 0: expecting 3 servers
==> Starting Consul agent...
==> Consul agent running!
           Version: 'v1.3.0'
           Node ID: 'c612a043-8906-d6e1-8f4b-ef1c8afb371b'
         Node name: 'consul-1'
        Datacenter: 'dc1' (Segment: '<all>')
            Server: true (Bootstrap: false)
       Client Addr: [0.0.0.0] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
      Cluster Addr: 192.168.153.129 (LAN: 8301, WAN: 8302)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false

==> Log data will now stream in as it occurs:

    2018/10/15 04:53:30 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb3777 Address:192.168.153.131:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371a Address:192.168.153.130:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371b Address:192.168.153.129:8300}]
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-1.dc1 192.168.153.129
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-1 192.168.153.129
    2018/10/15 04:53:30 [WARN] agent: Service name "LZZ.DEV.ClientService" will not be discoverable via DNS due to invalid characters. Valid characters include all alpha-numerics and dashes.
    2018/10/15 04:53:30 [WARN] agent: Service name "LZZ.PRO.ClientService" will not be discoverable via DNS due to invalid characters. Valid characters include all alpha-numerics and dashes.
    2018/10/15 04:53:30 [WARN] agent: check 'service:17947fbe-24ee-40e1-8e49-ea42415ada23' has deregister interval below minimum of 1m0s
    2018/10/15 04:53:30 [WARN] agent: check 'service:81d5b247-73d1-4ae5-9d1a-208770ca4e6a' has deregister interval below minimum of 1m0s
    2018/10/15 04:53:30 [INFO] agent: Started DNS server 0.0.0.0:8600 (udp)
    2018/10/15 04:53:30 [INFO] raft: Node at 192.168.153.129:8300 [Follower] entering Follower state (Leader: "")
    2018/10/15 04:53:30 [INFO] serf: Attempting re-join to previously known node: consul-3.dc1: 192.168.153.131:8302
    2018/10/15 04:53:30 [INFO] serf: Attempting re-join to previously known node: LZZ.PRODUCTS.WebServer: 192.168.153.133:8301
    2018/10/15 04:53:30 [INFO] consul: Adding LAN server consul-1 (Addr: tcp/192.168.153.129:8300) (DC: dc1)
    2018/10/15 04:53:30 [INFO] consul: Raft data found, disabling bootstrap mode
    2018/10/15 04:53:30 [INFO] consul: Handled member-join event for server "consul-1.dc1" in area "wan"
    2018/10/15 04:53:30 [WARN] agent/proxy: running as root, will not start managed proxies
    2018/10/15 04:53:30 [INFO] agent: Started DNS server 0.0.0.0:8600 (tcp)
    2018/10/15 04:53:30 [INFO] agent: Started HTTP server on [::]:8500 (tcp)
    2018/10/15 04:53:30 [INFO] agent: started state syncer
    2018/10/15 04:53:30 [INFO] serf: Attempting re-join to previously known node: consul-3: 192.168.153.131:8301
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-3.dc1 192.168.153.131
    2018/10/15 04:53:30 [WARN] memberlist: Refuting an alive message
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-2.dc1 192.168.153.130
    2018/10/15 04:53:30 [INFO] serf: Re-joined to previously known node: consul-3.dc1: 192.168.153.131:8302
    2018/10/15 04:53:30 [INFO] consul: Handled member-join event for server "consul-3.dc1" in area "wan"
    2018/10/15 04:53:30 [INFO] consul: Handled member-join event for server "consul-2.dc1" in area "wan"
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-3 192.168.153.131
    2018/10/15 04:53:30 [WARN] memberlist: Refuting a suspect message (from: consul-1)
    2018/10/15 04:53:30 [INFO] serf: EventMemberJoin: consul-2 192.168.153.130
    2018/10/15 04:53:30 [INFO] serf: Re-joined to previously known node: consul-3: 192.168.153.131:8301
    2018/10/15 04:53:30 [INFO] consul: Adding LAN server consul-3 (Addr: tcp/192.168.153.131:8300) (DC: dc1)
    2018/10/15 04:53:30 [INFO] consul: Adding LAN server consul-2 (Addr: tcp/192.168.153.130:8300) (DC: dc1)

 

  Client Addr的地址是[0.0.0.0],代表本机上的所有IPv4地址。集群地址是:192.168.153.129。稍后我们介绍命令一些主要参数的的作用。
 

step4:节点2

./consul agent -server -ui -bootstrap-expect=3 -data-dir=/tmp/consul -node=consul-2 -client=0.0.0.0 -bind=192.168.153.130 -datacenter=dc1 -join 192.168.153.129 # join 加入到129中
bootstrap_expect > 0: expecting 3 servers
==> Starting Consul agent...
==> Joining cluster...
    Join completed. Synced with 1 initial agents
==> Consul agent running!
           Version: 'v1.3.0'
           Node ID: 'c612a043-8906-d6e1-8f4b-ef1c8afb371a'
         Node name: 'consul-2'
        Datacenter: 'dc1' (Segment: '<all>')
            Server: true (Bootstrap: false)
       Client Addr: [0.0.0.0] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
      Cluster Addr: 192.168.153.130 (LAN: 8301, WAN: 8302)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false

==> Log data will now stream in as it occurs:

    2018/10/15 04:56:36 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb3777 Address:192.168.153.131:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371a Address:192.168.153.130:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371b Address:192.168.153.129:8300}]
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-2.dc1 192.168.153.130
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-2 192.168.153.130
    2018/10/15 04:56:36 [INFO] raft: Node at 192.168.153.130:8300 [Follower] entering Follower state (Leader: "")
    2018/10/15 04:56:36 [INFO] serf: Attempting re-join to previously known node: consul-3.dc1: 192.168.153.131:8302
    2018/10/15 04:56:36 [INFO] serf: Attempting re-join to previously known node: consul-3: 192.168.153.131:8301
    2018/10/15 04:56:36 [INFO] consul: Adding LAN server consul-2 (Addr: tcp/192.168.153.130:8300) (DC: dc1)
    2018/10/15 04:56:36 [INFO] consul: Raft data found, disabling bootstrap mode
    2018/10/15 04:56:36 [INFO] consul: Handled member-join event for server "consul-2.dc1" in area "wan"
    2018/10/15 04:56:36 [WARN] memberlist: Refuting a suspect message (from: consul-2)
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-1 192.168.153.129
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-3 192.168.153.131
    2018/10/15 04:56:36 [INFO] serf: Re-joined to previously known node: consul-3: 192.168.153.131:8301
    2018/10/15 04:56:36 [INFO] consul: Adding LAN server consul-1 (Addr: tcp/192.168.153.129:8300) (DC: dc1)
    2018/10/15 04:56:36 [INFO] consul: Adding LAN server consul-3 (Addr: tcp/192.168.153.131:8300) (DC: dc1)
    2018/10/15 04:56:36 [WARN] memberlist: Refuting a suspect message (from: consul-2.dc1)
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-1.dc1 192.168.153.129
    2018/10/15 04:56:36 [INFO] serf: EventMemberJoin: consul-3.dc1 192.168.153.131
    2018/10/15 04:56:36 [INFO] serf: Re-joined to previously known node: consul-3.dc1: 192.168.153.131:8302
    2018/10/15 04:56:36 [INFO] consul: Handled member-join event for server "consul-1.dc1" in area "wan"
    2018/10/15 04:56:36 [INFO] consul: Handled member-join event for server "consul-3.dc1" in area "wan"
    2018/10/15 04:56:36 [INFO] agent: Started DNS server 0.0.0.0:8600 (udp)
    2018/10/15 04:56:36 [WARN] agent/proxy: running as root, will not start managed proxies
    2018/10/15 04:56:36 [INFO] agent: Started DNS server 0.0.0.0:8600 (tcp)
    2018/10/15 04:56:36 [INFO] agent: Started HTTP server on [::]:8500 (tcp)
    2018/10/15 04:56:36 [INFO] agent: (LAN) joining: [192.168.153.129]
    2018/10/15 04:56:36 [INFO] agent: (LAN) joined: 1 Err: <nil>
    2018/10/15 04:56:36 [INFO] agent: started state syncer
 

step5:节点3

./consul agent -server -ui -bootstrap-expect=3 -data-dir=/tmp/consul -node=consul-3 -client=0.0.0.0 -bind=192.168.153.131 -datacenter=dc1 -join 192.168.153.129
bootstrap_expect > 0: expecting 3 servers
==> Starting Consul agent...
==> Joining cluster...
    Join completed. Synced with 1 initial agents
==> Consul agent running!
           Version: 'v1.3.0'
           Node ID: 'c612a043-8906-d6e1-8f4b-ef1c8afb3777'
         Node name: 'consul-3'
        Datacenter: 'dc1' (Segment: '<all>')
            Server: true (Bootstrap: false)
       Client Addr: [0.0.0.0] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
      Cluster Addr: 192.168.153.131 (LAN: 8301, WAN: 8302)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false

==> Log data will now stream in as it occurs:

    2018/10/15 05:01:15 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb3777 Address:192.168.153.131:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371b Address:192.168.153.129:8300} {Suffrage:Voter ID:c612a043-8906-d6e1-8f4b-ef1c8afb371a Address:192.168.153.130:8300}]
    2018/10/15 05:01:15 [INFO] raft: Node at 192.168.153.131:8300 [Follower] entering Follower state (Leader: "")
    2018/10/15 05:01:15 [INFO] serf: EventMemberJoin: consul-3.dc1 192.168.153.131
    2018/10/15 05:01:15 [INFO] serf: EventMemberJoin: consul-3 192.168.153.131
    2018/10/15 05:01:15 [INFO] serf: Attempting re-join to previously known node: consul-1.dc1: 192.168.153.129:8302
    2018/10/15 05:01:15 [INFO] serf: Attempting re-join to previously known node: consul-1: 192.168.153.129:8301
    2018/10/15 05:01:15 [INFO] consul: Adding LAN server consul-3 (Addr: tcp/192.168.153.131:8300) (DC: dc1)
    2018/10/15 05:01:15 [INFO] consul: Raft data found, disabling bootstrap mode
    2018/10/15 05:01:15 [INFO] consul: Handled member-join event for server "consul-3.dc1" in area "wan"
    2018/10/15 05:01:15 [WARN] agent/proxy: running as root, will not start managed proxies
    2018/10/15 05:01:15 [INFO] agent: Started DNS server 0.0.0.0:8600 (udp)
    2018/10/15 05:01:15 [INFO] agent: Started DNS server 0.0.0.0:8600 (tcp)
    2018/10/15 05:01:15 [INFO] agent: Started HTTP server on [::]:8500 (tcp)
    2018/10/15 05:01:15 [INFO] agent: (LAN) joining: [192.168.153.129]
    2018/10/15 05:01:15 [INFO] serf: EventMemberJoin: consul-1 192.168.153.129
    2018/10/15 05:01:15 [INFO] serf: Re-joined to previously known node: consul-1: 192.168.153.129:8301
    2018/10/15 05:01:15 [INFO] consul: Adding LAN server consul-1 (Addr: tcp/192.168.153.129:8300) (DC: dc1)
    2018/10/15 05:01:15 [INFO] serf: EventMemberJoin: consul-1.dc1 192.168.153.129
    2018/10/15 05:01:15 [INFO] serf: Re-joined to previously known node: consul-1.dc1: 192.168.153.129:8302
    2018/10/15 05:01:15 [INFO] consul: Handled member-join event for server "consul-1.dc1" in area "wan"
    2018/10/15 05:01:15 [INFO] agent: (LAN) joined: 1 Err: <nil>
    2018/10/15 05:01:15 [INFO] agent: started state syncer
 

step6:客户端1

./consul agent -bind 192.168.153.132 -client 192.168.153.132 -data-dir=/tmp/consul -node LZZ.DEV.WebServer -join 192.168.153.129
==> Starting Consul agent...
==> Joining cluster...
    Join completed. Synced with 1 initial agents
==> Consul agent running!
           Version: 'v1.3.0'
           Node ID: 'c7125043-8906-d6e1-8f4b-ef1c8afb371b'
         Node name: 'LZZ.DEV.WebServer'
        Datacenter: 'dc1' (Segment: '')
            Server: false (Bootstrap: false)
       Client Addr: [192.168.153.132] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
      Cluster Addr: 192.168.153.132 (LAN: 8301, WAN: 8302)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false

==> Log data will now stream in as it occurs:

    2018/10/15 05:03:15 [WARN] agent: Node name "LZZ.DEV.WebServer" will not be discoverable via DNS due to invalid characters. Valid characters include all alpha-numerics and dashes.
    2018/10/15 05:03:15 [INFO] serf: EventMemberJoin: LZZ.DEV.WebServer 192.168.153.132
    2018/10/15 05:03:15 [INFO] agent: Started DNS server 192.168.153.132:8600 (udp)
    2018/10/15 05:03:15 [WARN] agent/proxy: running as root, will not start managed proxies
    2018/10/15 05:03:15 [INFO] agent: Started DNS server 192.168.153.132:8600 (tcp)
    2018/10/15 05:03:15 [INFO] agent: Started HTTP server on 192.168.153.132:8500 (tcp)
    2018/10/15 05:03:15 [INFO] agent: (LAN) joining: [192.168.153.129]
    2018/10/15 05:03:15 [INFO] serf: EventMemberJoin: consul-1 192.168.153.129
    2018/10/15 05:03:15 [INFO] serf: EventMemberJoin: consul-3 192.168.153.131
    2018/10/15 05:03:15 [INFO] agent: (LAN) joined: 1 Err: <nil>
    2018/10/15 05:03:15 [INFO] agent: started state syncer
    2018/10/15 05:03:15 [INFO] consul: adding server consul-1 (Addr: tcp/192.168.153.129:8300) (DC: dc1)
    2018/10/15 05:03:15 [INFO] consul: adding server consul-3 (Addr: tcp/192.168.153.131:8300) (DC: dc1)
    2018/10/15 05:03:15 [INFO] agent: Synced node info

 

step6:客户端2

./consul agent -bind 192.168.153.133 -client 192.168.153.133 -data-dir=/tmp/consul -node LZZ.PRO.WebServer -join 192.168.153.129
==> Starting Consul agent...
==> Joining cluster...
    Join completed. Synced with 1 initial agents
==> Consul agent running!
           Version: 'v1.3.0'
           Node ID: '1aa2a043-8906-d6e1-8f4b-ef1c8afb371b'
         Node name: 'LZZ.PRO.WebServer'
        Datacenter: 'dc1' (Segment: '')
            Server: false (Bootstrap: false)
       Client Addr: [192.168.153.133] (HTTP: 8500, HTTPS: -1, gRPC: -1, DNS: 8600)
      Cluster Addr: 192.168.153.133 (LAN: 8301, WAN: 8302)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false

==> Log data will now stream in as it occurs:

    2018/10/15 05:04:26 [WARN] agent: Node name "LZZ.PRO.WebServer" will not be discoverable via DNS due to invalid characters. Valid characters include all alpha-numerics and dashes.
    2018/10/15 05:04:26 [INFO] serf: EventMemberJoin: LZZ.PRO.WebServer 192.168.153.133
    2018/10/15 05:04:26 [INFO] agent: Started DNS server 192.168.153.133:8600 (udp)
    2018/10/15 05:04:26 [WARN] agent/proxy: running as root, will not start managed proxies
    2018/10/15 05:04:26 [INFO] agent: Started DNS server 192.168.153.133:8600 (tcp)
    2018/10/15 05:04:26 [INFO] agent: Started HTTP server on 192.168.153.133:8500 (tcp)
    2018/10/15 05:04:26 [INFO] agent: (LAN) joining: [192.168.153.129]
    2018/10/15 05:04:26 [INFO] serf: EventMemberJoin: LZZ.DEV.WebServer 192.168.153.132
    2018/10/15 05:04:26 [INFO] serf: EventMemberJoin: consul-3 192.168.153.131
    2018/10/15 05:04:26 [INFO] serf: EventMemberJoin: consul-1 192.168.153.129
    2018/10/15 05:04:26 [INFO] agent: (LAN) joined: 1 Err: <nil>
    2018/10/15 05:04:26 [INFO] agent: started state syncer
    2018/10/15 05:04:26 [INFO] consul: adding server consul-3 (Addr: tcp/192.168.153.131:8300) (DC: dc1)
    2018/10/15 05:04:26 [INFO] consul: adding server consul-1 (Addr: tcp/192.168.153.129:8300) (DC: dc1)
    2018/10/15 05:04:26 [INFO] agent: Synced node info

  

  • -node:节点的名称
  • -bind:绑定的一个地址,用于节点之间通信的地址,可以是内外网,必须是可以访问到的地址
  • -server:这个就是表示这个节点是个server
  • -client:这个表示这个节点是个client
  • -bootstrap-expect:这个就是表示期望提供的SERVER节点数目,数目一达到,它就会被激活,然后就是LEADER了
  这样,五台服务器上的consul均已配置和启动完成,接下来我们看看他们之间的关系
 

step7:查看所有consul成员

./consul members
Node               Address               Status  Type    Build  Protocol  DC   Segment
consul-1           192.168.153.129:8301  alive   server  1.3.0  2         dc1  <all>
consul-2           192.168.153.130:8301  failed  server  1.3.0  2         dc1  <all>
consul-3           192.168.153.131:8301  alive   server  1.3.0  2         dc1  <all>
LZZ.DEV.WebServer  192.168.153.132:8301  alive   client  1.3.0  2         dc1  <default>
LZZ.PRO.WebServer  192.168.153.133:8301  alive   client  1.3.0  2         dc1  <default>
   如上可知,129,130,131三台consul的类型均是server类型,而132和133为client类型,极小化的集群搭建成功
 

step8:查看服务成员类型

./consul operator raft list-peers
Node      ID                                    Address               State     Voter  RaftProtocol
consul-3  c612a043-8906-d6e1-8f4b-ef1c8afb3777  192.168.153.131:8300  follower  true   3
consul-2  c612a043-8906-d6e1-8f4b-ef1c8afb371a  192.168.153.130:8300  follower  true   3
consul-1  c612a043-8906-d6e1-8f4b-ef1c8afb371b  192.168.153.129:8300  leader    true   3

   由图中可知,129目前为leader类型,为了验证之前“leader随环境变化而变化”的论证,我特意输入了命令“reboot”,请接着继续看下去。

 

step9:关闭一台服务,测试leader状态

  当129机器重新连上Consul后,我们再输入consul operator raft list-peers,可以看到此时的leader已经变为131的机器上面。
 
Node       ID                                    Address               State     Voter  RaftProtocol
consul-3   c612a043-8906-d6e1-8f4b-ef1c8afb3777  192.168.153.131:8300  leader    true   3
consul-1   c612a043-8906-d6e1-8f4b-ef1c8afb371b  192.168.153.129:8300  follower  true   3
consul-2   c612a043-8906-d6e1-8f4b-ef1c8afb371a  192.168.153.130:8300  follower  true   3
  所以,leader会随着环境的变化而变化,并且但只要超过一半的Server(这里是2/3还活着)还活着,集群是可以正常工作的。这也是为什么像Consul、ZooKeeper这样的分布式管理组件推荐我们使用3个或5个节点以上来部署的原因
 

step10:通过WEB查看服务状态

  我们还可以通过http://192.168.153.129:8500来查看整个集群的状态。

 

  接下来,我们创建一个net core的webApi应用程序,来向consul注册一个服务。
 

创建ASP.NET Core程序

  创建一个ASP.NET Web Application应用程序,项目名称自定

 
 
  创建一个HealthController控制器,用于提示该服务的状态。
using Microsoft.AspNetCore.Mvc;

namespace LZZ.DEV.WebServer.Controllers
{
    [Produces("application/json")]
    [Route("api/Health")]
    public class HealthController : Controller
    {
        [HttpGet]
        public IActionResult Get() => Ok("ok");
    }
}

 

   再创建一个应用程序扩展来建立连接和注册服务,利用Net core的管道灵活特性,我们可以非常容易的建立自己的扩展

using System;
using Consul;
using LZZ.DEV.WebServer.Models;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.Hosting;

namespace LZZ.DEV.WebServer
{
    public static class AppBuilderExtensions
    {
        public static IApplicationBuilder RegisterConsul(this IApplicationBuilder app,
            IApplicationLifetime lifetime,
            ServiceEntity serviceEntity)
        {
            var consulClient = new ConsulClient(x =>
                x.Address = new Uri($"http://{serviceEntity.ConsulIP}:{serviceEntity.ConsulPort}")); //请求注册的 Consul 地址
            var httpCheck = new AgentServiceCheck()
            {
                DeregisterCriticalServiceAfter = TimeSpan.FromSeconds(5), // 服务启动多久后注册
                Interval = TimeSpan.FromSeconds(10), // 健康检查时间间隔,或者称为心跳间隔
                HTTP = $"http://{serviceEntity.IP}:{serviceEntity.Port}/api/health", // 健康检查地址
                Timeout = TimeSpan.FromSeconds(5)    // 超时时间
            };

            // Register service with consul
            var registration = new AgentServiceRegistration()
            {
                Checks = new[] {httpCheck},
                ID = Guid.NewGuid().ToString(),
                Name = serviceEntity.ServiceName,
                Address = serviceEntity.IP,
                Port = serviceEntity.Port,
                Tags =
                    new[] {$"urlprefix-/{serviceEntity.ServiceName}"} // 添加 urlprefix-/servicename 格式的 tag 标签,以便 Fabio 识别
            };

            consulClient.Agent.ServiceRegister(registration).Wait(); // 服务启动时注册,内部实现其实就是使用 Consul API 进行注册(HttpClient发起)
            lifetime.ApplicationStopping.Register(() =>
            {
                consulClient.Agent.ServiceDeregister(registration.ID).Wait(); // 服务停止时取消注册
            });

            return app;
        }
    }
}

 

  当然,我们要使用consual,还需要安装consul依赖包
 
 
   最后,我们在Startup.cs的Configure配置函数中,增加启动时注册本地条目到consual,完整代码如下
 1         public void Configure(IApplicationBuilder app, IHostingEnvironment env, IApplicationLifetime lifetime)
 2         {
 3             app.UseMvc(routes =>
 4             {
 5                 routes.MapRoute(
 6                     name: "default",
 7                     template: "{controller=Home}/{action=Index}/{id?}");
 8             });
 9 
10             var serviceEntity = new ServiceEntity
11             {
12                 IP = "192.168.0.196",
13                 Port = Convert.ToInt32(Configuration["Service:Port"]),
14                 ServiceName = Configuration["Service:Name"],
15                 ConsulIP = Configuration["Consul:IP"],
16                 ConsulPort = Convert.ToInt32(Configuration["Consul:Port"])
17             };
18             app.RegisterConsul(lifetime, serviceEntity);
19         }
  
  appsettings.json配置文件如下:
 1 {
 2   "Service": {
 3     "Name": "LZZ.DEV.ClientService",
 4     "Port": "5000"
 5   },
 6   "Consul": {
 7     "IP": "192.168.0.115",
 8     "Port": "8500"
 9   },
10   "Logging": {
11     "LogLevel": {
12       "Default": "Warning"
13     }
14   },
15   "AllowedHosts": "*"
16 }
  
  好了,我们按下Ctrl+F5启动这个web应用程序瞧瞧。一切顺利,LZZ.DEV.WebServer已经被成功注册到consul中,使用相同方法也注册LZZ.PRO.WebServer到Consul中。
 

 

 

  我们还可以通过http://192.168.153.129:8500/v1/catalog/service/LZZ.PRO.ClientService来访问consul注册这条服务的详细信息。
 
[
  {
    "ID": "c612a043-8906-d6e1-8f4b-ef1c8afb371b",
    "Node": "consul-1",
    "Address": "192.168.153.129",
    "Datacenter": "dc1",
    "TaggedAddresses": {
      "lan": "192.168.153.129",
      "wan": "192.168.153.129"
    },
    "NodeMeta": {
      "consul-network-segment": ""
    },
    "ServiceKind": "",
    "ServiceID": "81d5b247-73d1-4ae5-9d1a-208770ca4e6a",
    "ServiceName": "LZZ.PRO.ClientService",
    "ServiceTags": [
      "urlprefix-/LZZ.PRO.ClientService"
    ],
    "ServiceAddress": "192.168.153.132",
    "ServiceWeights": {
      "Passing": 1,
      "Warning": 1
    },
    "ServiceMeta": {
      
    },
    "ServicePort": 5000,
    "ServiceEnableTagOverride": false,
    "ServiceProxyDestination": "",
    "ServiceProxy": {
      
    },
    "ServiceConnect": {
      
    },
    "CreateIndex": 2632,
    "ModifyIndex": 2632
  }
]

  关注ServiceAddress和ServicePort,即可完成对服务的调用。

 

总结

  本篇主要介绍以最少化的集群创建了一个consul集群,具体各项细节都没深入研究,后续有时间我会慢慢深入,毕竟ASP.NET core天生就是一个做微服务的,感谢博客园的各位大神资料和参考。

 

参考

  田园里的蟋蟀:《Docker & Consul & Fabio & ASP.NET Core 2.0 微服务跨平台实践

 

感谢阅读!!

posted @ 2018-10-14 20:52 另一个老李 阅读(...) 评论(...) 编辑 收藏