Use nginx as proxy with docker - nginx

Question

I currently try to use nginx as a proxy for elasticsearch engine, all with docker.
My run command for elasticsearch is the following :
docker run --name elasticsearch_5.2.1 \
-d \
elasticsearch:5.2.1
The one for nginx :
docker run --name nginx_1.11.10 \
-p 8200:80 \
-l elasticsearch_5.2.1:elasticsearch \
-v /my.conf:/etc/nginx/nginx.conf:ro \
-d \
nginx:1.11.10
And my nginx config is :
user nginx;
worker_processes 1;
error_log /var/log/nginx/error.log warn;
pid /var/run/nginx.pid;
events {
worker_connections 1024;
}
http {
upstream elasticsearch_proxy {
server elasticsearch:9200;
}
server {
listen 80;
location / {
proxy_pass http://elasticsearch_proxy;
proxy_http_version 1.1;
proxy_set_header Connection "Keep-Alive";
proxy_set_header Proxy-Connection "Keep-Alive";
}
}
}
But, when nginx start, I have this error :
2017/03/01 23:45:47 [emerg] 1#1: host not found in upstream "elasticsearch:9200" in /etc/nginx/nginx.conf:15
nginx: [emerg] host not found in upstream "elasticsearch:9200" in /etc/nginx/nginx.conf:15
I understand that nginx can't found elasticsearch with his alias. But I can't find the problem.
Is there someone who already has this problem ?
Thank you.

Answer 1

You need to create a user network.
docker create network my_app
And then run both containers on that network.
docker run --name elasticsearch_5.2.1 \
-d --network my_app \
elasticsearch:5.2.1
docker run --name nginx_1.11.10 \
-p 8200:80 \
-l elasticsearch_5.2.1:elasticsearch \
--network my_app \
-v /my.conf:/etc/nginx/nginx.conf:ro \
-d \
nginx:1.11.10
Then you should be able to resolve names properly as if they were DNS names.