使用nomad && consul && fabio 建立简单的微服务系统

具体每一个组件的功能就不详细说明了 nomad 一个调度工具，consul 一个服务发现，健康检查多数据中心支持的工具
fabio 一个基于consul的负载均衡&&动态路由工具,对于集成的话，很简单就是定义简单的service tag 便可，格式为：
urlprefix-/ 参考nomad 测试项目 https://github.com/rongfengliang/nomad-demo-template

nomad 安装

比较简单

https://releases.hashicorp.com/nomad/0.8.4/nomad_0.8.4_linux_amd64.zip

consul

比较简单

https://releases.hashicorp.com/consul/1.2.0/consul_1.2.0_linux_amd64.zip

fabio

https://github.com/fabiolb/fabio/releases
下载，配置环境变量便可

启动服务

• consul

  dev 模式

consul agent --dev

• nomad

  dev 模式

nomad agent --dev

• fabio
• consul 配置

配置consul 地址,使用默认的localhost:8500
一个参考配置
# These two lines are example of running fabio with HTTPS certificates
#proxy.cs = cs=lb;type=file;cert=/opt/fabio/certs.d/mydomain_com.ca-bundle.crt;key=/opt/fabio/certs.d/mydomain_com.key
#proxy.addr = :443;cs=lb;tlsmin=tls11;tlsmax=tls12;tlsciphers="0xc02f,0x9f,0xc030,0xc028,0xc014,0x6b,0x39,0x009d,0x0035",#             :80
proxy.addr = :9999
proxy.header.tls = Strict-Transport-Security
proxy.header.tls.value = "max-age=63072000; includeSubDomains"
ui.addr = 10.185.20.180:9998
ui.access = ro
runtime.gogc = 800
log.access.target = stdout
log.access.format =  - - [] ""   ".Referer" ".User-Agent" "" "" "" ""
log.access.level = INFO
registry.consul.addr = 10.185.20.180:8500
proxy.maxconn = 20000

• 部署简单nomad 服务

job "website" {
datacenters = ["dc1"]
type = "service"
update {
max_parallel = 1
min_healthy_time = "10s"
healthy_deadline = "3m"
progress_deadline = "10m"
auto_revert = false
canary = 0
}
migrate {
max_parallel = 1
health_check = "checks"
min_healthy_time = "10s"
healthy_deadline = "5m"
}
group "website" {
count = 1
restart {
attempts = 2
interval = "30m"
delay = "15s"
mode = "fail"
}
ephemeral_disk {
size = 300
}
task "graphql" {
driver = "docker"
config {
image = "dalongrong/mygraphql"
port_map {
website = 80
}
}
resources {
cpu = 500 # 500 MHz
memory = 256 # 256MB
network {
mbits = 10
port "website" {}
}
}
service {
name = "graphql-website"
tags = ["global", "website","graphql","urlprefix-/"]
port = "website"
check {
name = "alive"
type = "http"
interval = "10s"
path = "/"
timeout = "2s"
}
}
}
}
}

参考界面

• nomad
  
• consul
  
• fabio
  
• 进行实例缩放

group "website" {
# The "count" parameter specifies the number of the task groups that should
# be running under this group. This value must be non-negative and defaults
# to 1.
count = 3

效果

总结

三个工具集成起来，开发部署，缩放，版本管理，灰度，若是集成了openresty、 coredns、envoy 的话如更简单。

参考资料

https://www.nomadproject.io/docs/
https://fabiolb.net/quickstart/
https://www.consul.io/docs/index.html
https://github.com/rongfengliang/nomad-demo-template