使用nomad && consul && fabio 建立簡單的微服務系統

具體每一個組件的功能就不詳細說明了 nomad 一個調度工具，consul 一個服務發現，健康檢查多數據中心支持的工具
fabio 一個基於consul的負載均衡&&動態路由工具,對於集成的話，很簡單就是定義簡單的service tag 便可，格式爲：
urlprefix-/ 參考nomad 測試項目 https://github.com/rongfengliang/nomad-demo-template

nomad 安裝

比較簡單

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

consul

比較簡單

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

fabio

https://github.com/fabiolb/fabio/releases
下載，配置環境變量便可

啓動服務

• consul

  dev 模式

consul agent --dev

• nomad

  dev 模式

nomad agent --dev

• fabio
• consul 配置

配置consul 地址,使用默認的localhost:8500
一個參考配置
# 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

• 部署簡單nomad 服務

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"
}
}
}
}
}

參考界面

• nomad
  
• consul
  
• fabio
  
• 進行實例縮放

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

總結

三個工具集成起來，開發部署，縮放，版本管理，灰度，若是集成了openresty、 coredns、envoy 的話如更簡單。

參考資料

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