Consul 入门-运行

HashiCorp

Consul 是由 HashiCorp 公司开发的，它是一家专注于 DevOps 工具链的公司，旗下的明星级产品包括 Vagrant、Terraform、Vault、Nomad 以及 Consul，这些工具贯穿了持续交付的整个流程。

下载

在Consul 官网可以知道不同系统对应的下载方式

macOS

$ brew tap hashicorp/tap
$ brew install hashicorp/tap/consu

Windows

提供可二进制可执行程序的压缩包，分32位和64位

Linux系

提供相应包管理器的下载方式

• Ubuntu/Debian

$ curl -fsSL https://apt.releases.hashicorp.com/gpg | sudo apt-key add -
$ sudo apt-add-repository "deb [arch=amd64] https://apt.releases.hashicorp.com $(lsb_release -cs) main"
$ sudo apt-get update && sudo apt-get install consul

• CentOS/RHEL

$ sudo yum install -y yum-utils
$ sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/RHEL/hashicorp.repo
$ sudo yum -y install consul

• Fedora

$ sudo dnf install -y dnf-plugins-core
$ sudo dnf config-manager --add-repo https://rpm.releases.hashicorp.com/fedora/hashicorp.repo
$ sudo dnf -y install consul

• Amazon Linux

$ sudo yum install -y yum-utils
$ sudo yum-config-manager --add-repo https://rpm.releases.hashicorp.com/AmazonLinux/hashicorp.repo
$ sudo yum -y install consul

• Homebrew

$ brew tap hashicorp/tap
$ brew install hashicorp/tap/consul

也提供对应操作架构的二进制下载链接

• 32-bit
• 64-bit
• Arm64
• Armelv5
• Armhfv6

另外，Consul 是通过 Golang 编写的开源软件，可以从 Github 上找到源码自行编译。

$ git clone https://github.com/hashicorp/consul.git -depth=1
$ cd consul
$ make tools
$ make dev

运行 Server&Client

回顾上一篇《Consul 入门-初识》，我们知道 Consul 是 C/S 架构以及各端能力

运行 Server

$ consul agent --server=true --ui=true --data-dir=s-data --node=server1 --dev
==> Starting Consul agent...
           Version: '1.9.4'
           Node ID: '34d5bfeb-3ed4-6aa1-f68d-d30950450fc9'
         Node name: 'server1'
        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, Auto-Encrypt-TLS: false

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

可以从输出信息里面看到 Server 节点的一些关键信息以及竞选 Leader 成功（毕竟只有它一个人）

运行 Client

$ consul agent  --data-dir=c-data --join=127.0.0.1:8301 --serf-lan-port=8303 --serf-wan-port=8305  --dns-port=8601 --server-port=8304   --http-port=8503  --server=false --enable-script-checks   --node=client1 --config-dir=config
==> Starting Consul agent...
           Version: '1.9.4'
           Node ID: '2b05ee18-1b09-3b0b-7431-ef79783d9758'
         Node name: 'client1'
        Datacenter: 'dc1' (Segment: '')
            Server: false (Bootstrap: false)
       Client Addr: [127.0.0.1] (HTTP: 8503, HTTPS: -1, gRPC: -1, DNS: 8601)
      Cluster Addr: 10.8.124.122 (LAN: 8303, WAN: 8305)
           Encrypt: Gossip: false, TLS-Outgoing: false, TLS-Incoming: false, Auto-Encrypt-TLS: false
...

程序同样会显示 Client 的一些相信息，由于Server 和 Client 是运行在同一台机器上，默认端口与 Server 的冲突了，所以通过参数--serf-lan-port=8303 --serf-wan-port=8305 --dns-port=8601 --server-port=8304 --http-port=8503 进行了指定。

此时我们观察 Server 端的程序输出内容，可以看到 Client1 与 Server 的连接信息：

  2021-08-29T16:47:10.385+0800 [DEBUG] agent.router.manager: Rebalanced servers, new active server: number_of_servers=1 active_server="server1 (Addr: tcp/127.0.0.1:8300) (DC: dc1)"
  2021-08-29T16:47:10.385+0800 [DEBUG] agent.router.manager: Rebalanced servers, new active server: number_of_servers=1 active_server="server1.dc1 (Addr: tcp/127.0.0.1:8300) (DC: dc1)"
  2021-08-29T16:48:04.265+0800 [DEBUG] agent: Skipping remote check since it is managed automatically: check=serfHealth
  2021-08-29T16:48:04.265+0800 [DEBUG] agent: Node info in sync
  2021-08-29T16:49:18.849+0800 [DEBUG] agent: Skipping remote check since it is managed automatically: check=serfHealth
  2021-08-29T16:49:18.849+0800 [DEBUG] agent: Node info in sync
  2021-08-29T16:49:18.993+0800 [DEBUG] agent.server.memberlist.lan: memberlist: Stream connection from=127.0.0.1:54711
  2021-08-29T16:49:18.993+0800 [INFO]  agent.server.serf.lan: serf: EventMemberJoin: client1 10.8.124.122
  2021-08-29T16:49:18.993+0800 [INFO]  agent.server: member joined, marking health alive: member=client1
  2021-08-29T16:49:19.176+0800 [DEBUG] agent.server.serf.lan: serf: messageJoinType: client1
  2021-08-29T16:49:19.192+0800 [DEBUG] agent.server.serf.lan: serf: messageJoinType: client1
  2021-08-29T16:49:19.294+0800 [DEBUG] agent.server.serf.lan: serf: messageJoinType: client1
  2021-08-29T16:49:19.393+0800 [DEBUG] agent.server.serf.lan: serf: messageJoinType: client1

通过 Consul 的命令可以查看现在的成员情况：

$ consul members
Node     Address             Status  Type    Build  Protocol  DC   Segment
server1  127.0.0.1:8301      alive   server  1.9.4  2         dc1  <all>
client1  10.8.124.122:8303  alive   client  1.9.4  2         dc1  <default>

注册一个服务

我们先用Ctrl-C 暂停 Client 端代码，在配置文件夹config中增加文件redis.json

{
  "service": [
  {
    "name": "redis",
    "tags": ["master"],
    "address": "127.0.0.1",
    "port": 6379,
  }
 ]
}

然后重新运行，可以看到服 redis 服务已经被注册

2021-08-29T17:03:04.556+0800 [INFO]  agent: Synced node info
2021-08-29T17:03:04.556+0800 [INFO]  agent: Synced service: service=redis

来验证一下是否可以通过 Consul 的dns服务找到

$ dig @127.0.0.1 -p 8601 redis.sevice.consul

; <<>> DiG 9.10.6 <<>> @127.0.0.1 -p 8601 redis.sevice.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 39225
;; flags: qr aa rd; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;redis.sevice.consul.		IN	A

;; AUTHORITY SECTION:
consul.			0	IN	SOA	ns.consul. hostmaster.consul. 1630227874 3600 600 86400 0

;; Query time: 0 msec
;; SERVER: 127.0.0.1#8601(127.0.0.1)
;; WHEN: Sun Aug 29 17:04:34 CST 2021
;; MSG SIZE  rcvd: 98