Nginx反向代理到Golang服务器的Docker问题

Question

I have nginx reverse proxying to a golang server, each in its own docker container and running normally. I keep getting this error in nginx when trying to connect to Go container, BOTH on my local Mac machine and on the production server Linux Debian. It was working on my local Mac machine a week ago and all of a sudden it doesn't anymore

nginx_1  | 2017/09/28 01:29:54 [error] 5#5: *12 upstream timed out (110: Connection timed out) while connecting to upstream, client: 172.23.0.1, server: , request: "GET /api/about HTTP/1.1", upstream: "http://67.199.248.12:8080/api/about", host: "localhost"

can someone explain what's going on here? What is 67.199.248.12 and why isn't Nginx able to ping/connect to the Go container?

here's what's inside /etc/hosts in Go container

127.0.0.1   localhost
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
172.23.0.5  31f4103f002c

here's my nginx.conf

upstream gogo {
  server go:8080 weight=10 max_fails=3 fail_timeout=30s;
}

server {
  listen 80;

  location /api/ {
    resolver            127.0.0.1 valid=30s;
    proxy_pass          http://gogo;
    proxy_redirect      off;
    proxy_set_header    Host $host;
    proxy_set_header    X-Real-IP $remote_addr;
    proxy_set_header    X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header    X-Forwarded-Host $server_name;
  }
}

I'm using docker-compose v3 to run nginx and docker

  nginx:
    restart: always
    image: nginx
    volumes:
      - ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf
    ports:
      - "80:80"
    command: /bin/bash -c "nginx -g 'daemon off;'"

  go:
    build:
      context: ./api
    expose:
      - "8080"
    depends_on:
      - nginx

go code:

func main() {
    router := mux.NewRouter().StrictSlash(true)
    router.HandleFunc("/api/about", About).Methods("GET")
    log.Fatal(http.ListenAndServe(":8080", router))
}

Answer 1

It seems like containers can't ping each other ?

I see two possibilities :

First : Ensure each container are on the same network

docker run --network=host ...

or create a network

docker network create nginx_go
docker run --network=nginx_go ...

Second : Use docker-compose

version: '3.3'

services:
    nginx:
      image: nginx
      # others details like volumes...
    server:
        image: go