Hashicorp Nomad: How to configure one service advertise multiple port

之前在Hashicorp forum看到一个发问 Can a service advertise multiple ports? 所以记录下来。

情境

User在一个task里使用2个port, port name分别是http, metrics, 再向Consul注册一个service, service name为awesome-api, 想要达到2个port注册相同的service,

一般来说会为注册不同的service name如:

...
service {
      name    = "awesome-api-http"
      port    = "http"
    }
    
service {
      name    = "awesome-api-metrics"
      port    = "metrics"
    }
...

User的写法如下:

...
network {
      port "http"    { host_network = "private" }
      port "metrics" {
        host_network = "private"
        static       = "9090"
      }
      //port "metrics" { host_network = "private" }
    }
    
service {
      name    = "awesome-api"
      port    = "http"
      //port  = "metrics"
    }
...

把注解拿掉会报错

Dimension network: reserved port collision metrics=9090 exhausted on [x] nodes

解法

有网友回复可以使用tag来达到这需求:

    service {
      name = "awesome-api"
      port = "http"
      tags = ["http"]
    }

    service {
      name = "awesome-api"
      port = "metrics"
      tags = ["metrics"]
    }

访问的endpoint会变成 http.awesome-api.service.consul 与 metrics.awesome-api.service.consul
这样即可达成一个service多个port的需求