Consul入门

最新推荐文章于 2025-07-24 10:10:15 发布

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最新推荐文章于 2025-07-24 10:10:15 发布

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分类专栏： consul 文章标签： consul 服务注册

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Consul简介

Consul有多个组件，但总体而言，它是基础架构中的一款服务发现和配置的工具。它提供了几个关键功能：

服务发现：Consul client 可以提供服务，例如api或mysql，也可以使用Consul client来发现指定服务的提供者。使用DNS或HTTP，应用程序可以轻松找到他们所依赖的服务。
健康检查：Consul client 可以提供任何数量的健康检查，或者与给定的服务（“Web服务器是否返回200 OK”），或与本地节点（“内存利用率是否低于90％”）相关联。可以使用此信息来监控集群运行状况，服务发现组件使用此信息将流量从有问题的主机中移除出去。
KV Store：应用程序可以使用Consul的分层键/值存储，包括动态配置，功能标记，协调，leader选举等等。简单的HTTP API使其易于使用。
多数据中心：Consul支持多个数据中心。这意味着Consul的用户不必担心构建额外的抽象层以扩展到多个区域。
　　Consul旨在对DevOps社区和应用程序开发人员友好，使其成为现代化，弹性基础架构的完美选择。

Consul的安装

打开官网的下载地址
在这里插入图片描述
选择对应的版本进行下载。本文是再Windows环境下的安装与配置。

下载完成后解压会得到一个exe文件。将这个exe文件放在C:\Windows\system32这个目录下面然后打开cmd。
输入consul检擦是否安装完成。

PS C:\Windows\system32> consul
Usage: consul [--version] [--help] <command> [<args>]

Available commands are:
    acl            Interact with Consul's ACLs
    agent          Runs a Consul agent
    catalog        Interact with the catalog
    config         Interact with Consul's Centralized Configurations
    connect        Interact with Consul Connect
    debug          Records a debugging archive for operators
    event          Fire a new event
    exec           Executes a command on Consul nodes
    force-leave    Forces a member of the cluster to enter the "left" state
    info           Provides debugging information for operators.
    intention      Interact with Connect service intentions
    join           Tell Consul agent to join cluster
    keygen         Generates a new encryption key
    keyring        Manages gossip layer encryption keys
    kv             Interact with the key-value store
    leave          Gracefully leaves the Consul cluster and shuts down
    lock           Execute a command holding a lock
    login          Login to Consul using an auth method
    logout         Destroy a Consul token created with login
    maint          Controls node or service maintenance mode
    members        Lists the members of a Consul cluster
    monitor        Stream logs from a Consul agent
    operator       Provides cluster-level tools for Consul operators
    reload         Triggers the agent to reload configuration files
    rtt            Estimates network round trip time between nodes
    services       Interact with services
    snapshot       Saves, restores and inspects snapshots of Consul server state
    tls            Builtin helpers for creating CAs and certificates
    validate       Validate config files/directories
    version        Prints the Consul version
    watch          Watch for changes in Consul

这样就表示安装成功了。

Consul运行与配置

输入consul agent -dev

PS C:\Windows\system32> consul agent -dev
==> Starting Consul agent...
==> Consul agent running!
           Version: 'v1.5.1'
           Node ID: '262ed46b-3d26-8907-3ce9-b094d1eeca7e'
         Node name: 'DESKTOP-FERRARI'
        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:

    2019/07/03 11:44:04 [DEBUG] agent: Using random ID "262ed46b-3d26-8907-3ce9-b094d1eeca7e" as node ID
    2019/07/03 11:44:04 [DEBUG] tlsutil: Update with version 1
    2019/07/03 11:44:04 [DEBUG] tlsutil: OutgoingRPCWrapper with version 1
    2019/07/03 11:44:04 [DEBUG] tlsutil: IncomingRPCConfig with version 1
    2019/07/03 11:44:04 [DEBUG] tlsutil: OutgoingRPCWrapper with version 1
    2019/07/03 11:44:04 [INFO] raft: Initial configuration (index=1): [{Suffrage:Voter ID:262ed46b-3d26-8907-3ce9-b094d1eeca7e Address:127.0.0.1:8300}]
    2019/07/03 11:44:04 [INFO] raft: Node at 127.0.0.1:8300 [Follower] entering Follower state (Leader: "")
    2019/07/03 11:44:04 [INFO] serf: EventMemberJoin: DESKTOP-FERRARI.dc1 127.0.0.1
    2019/07/03 11:44:04 [INFO] serf: EventMemberJoin: DESKTOP-FERRARI 127.0.0.1
    2019/07/03 11:44:04 [INFO] consul: Adding LAN server DESKTOP-FERRARI (Addr: tcp/127.0.0.1:8300) (DC: dc1)
    2019/07/03 11:44:04 [INFO] consul: Handled member-join event for server "DESKTOP-FERRARI.dc1" in area "wan"
    2019/07/03 11:44:04 [DEBUG] agent/proxy: managed Connect proxy manager started
    2019/07/03 11:44:04 [INFO] agent: Started DNS server 127.0.0.1:8600 (tcp)
    2019/07/03 11:44:04 [INFO] agent: Started DNS server 127.0.0.1:8600 (udp)
    2019/07/03 11:44:04 [INFO] agent: Started HTTP server on 127.0.0.1:8500 (tcp)
    2019/07/03 11:44:04 [INFO] agent: started state syncer
    2019/07/03 11:44:04 [INFO] agent: Started gRPC server on 127.0.0.1:8502 (tcp)
    2019/07/03 11:44:04 [WARN] raft: Heartbeat timeout from "" reached, starting election
    2019/07/03 11:44:04 [INFO] raft: Node at 127.0.0.1:8300 [Candidate] entering Candidate state in term 2
    2019/07/03 11:44:04 [DEBUG] raft: Votes needed: 1
    2019/07/03 11:44:04 [DEBUG] raft: Vote granted from 262ed46b-3d26-8907-3ce9-b094d1eeca7e in term 2. Tally: 1
    2019/07/03 11:44:04 [INFO] raft: Election won. Tally: 1
    2019/07/03 11:44:04 [INFO] raft: Node at 127.0.0.1:8300 [Leader] entering Leader state
    2019/07/03 11:44:04 [INFO] consul: cluster leadership acquired
    2019/07/03 11:44:04 [INFO] consul: New leader elected: DESKTOP-FERRARI
    2019/07/03 11:44:04 [INFO] connect: initialized primary datacenter CA with provider "consul"
    2019/07/03 11:44:04 [DEBUG] consul: Skipping self join check for "DESKTOP-FERRARI" since the cluster is too small
    2019/07/03 11:44:04 [INFO] consul: member 'DESKTOP-FERRARI' joined, marking health alive
    2019/07/03 11:44:04 [DEBUG] agent: Skipping remote check "serfHealth" since it is managed automatically
    2019/07/03 11:44:04 [INFO] agent: Synced node info
    2019/07/03 11:44:04 [DEBUG] agent: Node info in sync
    2019/07/03 11:44:05 [DEBUG] agent: Skipping remote check "serfHealth" since it is managed automatically
    2019/07/03 11:44:05 [DEBUG] agent: Node info in sync

出现这样表示运行成功了。

打开 http://127.0.0.1:8500/ui/dc1/services查看consul的运行状态。

在这里插入图片描述

服务注册

创建consul.d的配置文件夹

  mkdir ./consul.d

创建一个服务的.json的配置文件。

 echo '{"service": {"name": "web", "tags": ["rails"], "port": 80}}' > ./consul.d/web.json

重启agent

consul agent -dev -config-dir=./consul.d

==> Starting Consul agent...
...
    [INFO] agent: Synced service 'web'
...

DNS API

dig @127.0.0.1 -p 8600 web.service.consul

;; QUESTION SECTION:
;web.service.consul.        IN  A

;; ANSWER SECTION:
web.service.consul. 0   IN  A   127.0.0.1

再用SRV的方式检查一下

C:\Windows\system32>dig @127.0.0.1 -p 8600 web.service.consul SRV

; <<>> DiG 9.9.7 <<>> @127.0.0.1 -p 8600 web.service.consul SRV
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 63393
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 3
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;web.service.consul.            IN      SRV

;; ANSWER SECTION:
web.service.consul.     0       IN      SRV     1 1 80 DESKTOP-FERRARI.node.dc1.consul.

;; ADDITIONAL SECTION:
DESKTOP-FERRARI.node.dc1.consul. 0 IN   A       127.0.0.1
DESKTOP-FERRARI.node.dc1.consul. 0 IN   TXT     "consul-network-segment="

;; Query time: 0 msec
;; SERVER: 127.0.0.1#8600(127.0.0.1)
;; WHEN: Wed Jul 03 14:14:49 ?D1ú±ê×?ê±?? 2019
;; MSG SIZE  rcvd: 150

可以看到他说已经在一台电脑上注册了这个DNS.

我们还可以使用域名过滤的方式在注册一个

dig @127.0.0.1 -p 8600 rails.web.service.consul

; <<>> DiG 9.9.7 <<>> @127.0.0.1 -p 8600 rails.web.service.consul
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22904
;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 2
;; WARNING: recursion requested but not available

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;rails.web.service.consul.      IN      A

;; ANSWER SECTION:
rails.web.service.consul. 0     IN      A       127.0.0.1

;; ADDITIONAL SECTION:
rails.web.service.consul. 0     IN      TXT     "consul-network-segment="

;; Query time: 0 msec
;; SERVER: 127.0.0.1#8600(127.0.0.1)
;; WHEN: Wed Jul 03 14:16:52 ?D1ú±ê×?ê±?? 2019
;; MSG SIZE  rcvd: 105

再用 HTTP API来查看服务

curl http://localhost:8500/v1/catalog/service/web
[
    {
        "ID": "b9896ed0-77f7-6f47-05d0-a76c32bd592d",
        "Node": "DESKTOP-FERRARI",
        "Address": "127.0.0.1",
        "Datacenter": "dc1",
        "TaggedAddresses": {
            "lan": "127.0.0.1",
            "wan": "127.0.0.1"
        },
        "NodeMeta": {
            "consul-network-segment": ""
        },
        "ServiceKind": "",
        "ServiceID": "web",
        "ServiceName": "web",
        "ServiceTags": [
            "rails"
        ],
        "ServiceAddress": "",
        "ServiceWeights": {
            "Passing": 1,
            "Warning": 1
        },
        "ServiceMeta": {},
        "ServicePort": 80,
        "ServiceEnableTagOverride": false,
        "ServiceProxyDestination": "",
        "ServiceProxy": {},
        "ServiceConnect": {},
        "CreateIndex": 10,
        "ModifyIndex": 10
    }
]

Consul 健康监测

创建两个检测的文件

echo '{"check": {"name": "ping", "args": ["ping", "-c1", "google.com"], "interval": "30s"}}' >./consul.d/ping.json

echo '{"service": {"name": "web", "tags": ["rails"], "port": 80, "check": {"args": ["curl", "localhost"], "interval": "10s"}}}' >./consul.d/web.json

重启一下consul agent

consul agent -dev -config-dir ./consul.d  -enable-script-checks=true

现在来检查一下

curl http://localhost:8500/v1/health/state/critical



StatusCode        : 200
StatusDescription : OK
Content           : [
                        {
                            "Node": "DESKTOP-FERRARI",
                            "CheckID": "service:web",
                            "Name": "Service 'web' check",
                            "Status": "critical",
                            "Notes": "",
                            "Output": "  % Total    %...
RawContent        : HTTP/1.1 200 OK
                    Vary: Accept-Encoding
                    X-Consul-Effective-Consistency: leader
                    X-Consul-Index: 28
                    X-Consul-Knownleader: true
                    X-Consul-Lastcontact: 0
                    Content-Length: 786
                    Content-Type: application/...
Forms             : {}
Headers           : {[Vary, Accept-Encoding], [X-Consul-Effective-Consistency, leader], [X-Consul-Index, 28], [X-Consul
                    -Knownleader, true]...}
Images            : {}
InputFields       : {}
Links             : {}
ParsedHtml        : mshtml.HTMLDocumentClass
RawContentLength  : 786