counting.hcl

service {
  name    = "counting"
  id      = "counting"
  port    = 9003
  address = "127.0.0.2"

  connect {
    sidecar_service {}
  }

  check {
    id       = "counting-check"
    http     = "http://localhost:9003/health"
    method   = "GET"
    interval = "1s"
    timeout  = "1s"
  }
}

dashboard.hcl

service {
  name = "dashboard"
  port = 9002
  address = "127.0.0.1"

  connect {
    sidecar_service {
      proxy {
        upstreams = [
          {
            destination_name = "counting"
            local_bind_port  = 5000
            destination_peer = "dc2"
          },
        ]
      }
    }
  }

  check {
    id       = "dashboard-check"
    http     = "http://localhost:9002/health"
    method   = "GET"
    interval = "1s"
    timeout  = "1s"
  }
}

export-counting.hcl

Kind = "exported-services"
Name = "default"
Services = [
  {
    Name = "counting"
    Consumers = [
      {
        Peer = "dc1"
      }
    ]
  }
]

proxy-defaults.hcl

Kind = "proxy-defaults"
Name = "global"
MeshGateway {
  mode = "local"
}

Prerequisite

• If running on macOS, add an additional IP to loopback

  sudo ifconfig lo0 alias 127.0.0.2
  

• Consul 1.14.3

• A supported envoy binary

Steps

• Start dc1 with dashboard service registered

  consul agent -dev -bind 127.0.0.1 -client 127.0.0.1 -datacenter dc1 -config-file dashboard.hcl
  

• Start dc2 with counting service registered

  consul agent -dev -bind 127.0.0.2 -client 127.0.0.2 -datacenter dc2 -config-file counting.hcl
  

• Generate peering token in dc1

  consul peering generate-token -name dc2 | pbcopy
  

• Establish peering in dc2

  consul peering establish -name dc1 -http-addr 127.0.0.2:8500 -peering-token $(pbpaste)
  

• Run mesh-gateway in dc1

  consul connect envoy -gateway=mesh -register -service "gateway-primary" -address "127.0.0.1:8443" -wan-address "127.0.0.1:8443"
  

• Run mesh-gateway in dc2

  export CONSUL_HTTP_ADDR=http://127.0.0.2:8500
  export CONSUL_GRPC_ADDR=http://127.0.0.2:8502
  consul connect envoy -gateway=mesh -register -service "gateway-secondary" -address "127.0.0.2:8443" -wan-address "127.0.0.2:8443"  -admin-bind 127.0.0.2:19000
  

• Run dummy Python webservers for counting and dashboard

  mkdir -p health
  python3 -m http.server --bind 127.0.0.1 9002
  

  mkdir -p health
  python3 -m http.server --bind 127.0.02 9003
  

• Run dashboard sidecar proxy

  consul connect envoy -sidecar-for dashboard -admin-bind 127.0.0.1:19001
  

• Run counting sidecar proxy

  export CONSUL_HTTP_ADDR=http://127.0.0.2:8500
  export CONSUL_GRPC_ADDR=http://127.0.0.2:8502
  consul connect envoy -sidecar-for counting -admin-bind 127.0.0.2:19001
  

• Export counting to dc1

  consul config write -http-addr 127.0.0.2:8500 export-counting.hcl
  

• Write proxy-defaults to both DCs

  consul config write proxy-defaults.hcl  
  consul config write -http-addr 127.0.0.2:8500 proxy-defaults.hcl