nginx-proxy for more than one node app docker

Question

i am trying nginx reverse proxy multiple container .

i have 2 container which have node add one listen on 8085 and other on 8086 i want them to access by

node.app1.com

node.app2.com

so i used jwilder/nginx-proxy:latest which will sit in fount of both of these container and will act as revers proxy . so here is my compose.yml file.

docker-compose.yml

version: "3"
services:
  node-proxy:
    build:  ./node-proxy
    container_name : node-proxy
    restart : always
    volumes:  
        -  /var/run/docker.sock:/tmp/docker.sock:ro
    ports:
      - 80:80
      - 443:443
  node-app1:
    build:  ./app1
    container_name : node-app1
    restart: always
    environment:
      VIRTUAL_HOST: node.app1.com
    depends_on:
      - node-proxy
  node-app2:
    build:  ./app2
    container_name : node-app2
    restart: always
    environment:
      VIRTUAL_HOST: node.app2.com
    depends_on:
      - node-proxy

./node-proxy/Dockerfile

FROM jwilder/nginx-proxy:latest

./app1/app1.js

var http = require("http");

http.createServer(function (request, response) {

   response.writeHead(200, {'Content-Type': 'text/plain'});
   response.end('Hello World 1\n');
}).listen(8085);

./app1/Dockerfile

FROM node:6.11
WORKDIR /app2
COPY app1.js .
CMD node app1.js
Expose 8085

./app2/app2.js

var http = require("http");

http.createServer(function (request, response) {

   response.writeHead(200, {'Content-Type': 'text/plain'});
   response.end('Hello World 2\n');
}).listen(8086);

./app2/Dockerfile

FROM node:6.11
WORKDIR /app2
COPY app2.js .
CMD node app2.js
Expose 8086

So when i do

docker-compose up

all my containers are up and running

but when do node.app1.com --> it say's unknown host .

so to check wether request is coming to proxy i tryed calling http://localhost from browser and it says 503

i also checked nginx.config in side container by

docker exec -it node-proxy_id bash

cat /etc/nginx/conf.d/

and its there but i think when i do node.app1.com request not coming to proxy . i am not getting where i have missed , can some one help me out with this .

Thanks for your time

So are your node apps running on both 172.18.0.4:8086 and 172.18.0.3:8085 respectively? Can I see the configuration file that you use to make them as such? — Kent Shikama
– Kent Shikama, Commented Aug 20, 2017 at 9:43
yes both of my hello word node app are running fine , with exposed port specified in Dockerfile which is shared above . — Abhi Adr
– Abhi Adr, Commented Aug 21, 2017 at 17:16
Yeah I do see where port 8086 and 8085 come from but where do the ip addresses 172.18.0.4 and 172.18.0.3 come from? — Kent Shikama
– Kent Shikama, Commented Aug 22, 2017 at 12:14
it's a container IP which is generated automatically when we do compose up . — Abhi Adr
– Abhi Adr, Commented Aug 27, 2017 at 5:30

Mathias · Accepted Answer · 2017-08-22 12:20:51Z

3

+25

Look at the ports of your app / Dockerfile:

./app1/app1.js

}).listen(8085);

and

./app1/Dockerfile

Expose 8086

they are missmatching.

The part i was missing is that jwilder/nginx-proxy is reflecting docker to look for containers that needs to be proxied.

Original post:

I guess that your problem is that reverse proxy container cannot reach each app. Therefor remove the depends_on from node-app1 and node-app2 and add in node-proxy:

links:
 - node-app1
 - node-app2

The reverse proxy requires both apps to be started and not the other way around. Also use links instead of depends_on.

From the docs:

depends_on

Express dependency between services, which has two effects:

docker-compose up will start services in dependency order. In the following example, db and redis will be started before web.

docker-compose up SERVICE will automatically include SERVICE’s dependencies. In the following example, docker-compose up web will also create and start db and redis.

links

Containers for the linked service will be reachable at a hostname identical to the alias, or the service name if no alias was specified.

Links also express dependency between services in the same way as depends_on, so they determine the order of service startup.

I'm also not sure how you get to the IP addresses of this containers in your proxy config. You can use (as it says in the documentation) the alias or service name instead. (in your case node-app1 and node-app2)

edited Aug 22, 2017 at 12:20

answered Aug 20, 2017 at 14:45

Mathias

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5 Comments

Abhi Adr Over a year ago

see the last image in nginx.config where configuration is generated based on config of compose..yml file . i have manually went in side proxy container and ping with the domain provide , it's working fine ( so reverse proxy container is able to reach both app1 and app2 container ) the problem here is my hosts file dose note resolve the domain name provided in VIRTUAL_HOST [ as show in 1st image of question , request is coming to proxy when i tried calling localhost from browser and it says 503 ]

Abhi Adr Over a year ago

IF I MANUALLY EDIT the hosts file of the system like this > Then it's Working Fine >>>>>> 127.0.0.1 localhost 127.0.0.1 node.app1.com 127.0.0.1 node.app2.com >>>>> but it's not practical editing DNS ( hosts file ) every time i change the value of VIRTUAL_HOST.

Mathias Over a year ago

I guess as you defined the dependency in the wrong way it is probably working in some strange cases. Have you tried to use links in the proxy service?

Abhi Adr Over a year ago

yea i have tried with links , but still it is not working ! :(

Mathias Over a year ago

You have a port missmatch in your app and docker file. Updated the answer.

James Yang · Accepted Answer · 2017-08-29 06:05:49Z

1

When you set links or depends_on to the other services, docker-compose will set up other services host name as its container_name in same docker network by default.

In your case, I would suggest to add links as @Mathias respond for.

version: "3"
services:
  node-app1:
    build:  ./app1
    container_name : node-app1
    restart: always
    expose:
      - "8085"
    environment:
      VIRTUAL_HOST: node.app1.com
  node-app2:
    build:  ./app2
    container_name : node-app2
    restart: always
    expose:
      - "8086"
    environment:
      VIRTUAL_HOST: node.app2.com
  node-proxy:
    build:  ./node-proxy
    container_name : node-proxy
    restart : always
    links:
        - node-app1
        - node-app2
    volumes:
        -  /var/run/docker.sock:/tmp/docker.sock:ro
    ports:
        - 80:80
        - 443:443

Updated:

I noticed that Nginx config have upstream directive to hold multiple host names. You should be able to curl the node-app1 as:

$ curl -H 'Host: node.app1.com' localhost
Hello World 1

You can also modify last line in etc/hosts file in your node-proxy container as:

172.20.0.4 [docker-network-alias] node.app1.com node.app2.com

Then you should be able to visit http://node.app1.com directly inside your node-proxy container.

Here's a tutorial to set up nginx virtual hosts on ubuntu 16 04

Comment I:

In my understanding, the nginx-proxy is tend to proxy request to back-end service which does not have to register a hostname in /etc/hosts file. So we fire a request with Host header which is a virtual hostname in Nginx upstream block.

The nginx-proxy have done this part for you when you create the environment variable VIRTUAL_HOST in each app container setting. But it does not mean we can directly visit the node.app1.com in our browser and expect the request will be proxied and respond by node-app1 container.

Back to request forwarding part, the request come to localhost at port 80/443 which is listened by Nginx. Nginx then check the Host header to go into specific location block. That is why you cannot directly visit http://node.app1.com in your browser, because that hostname is never be really registered in etc/hosts, so it will never be addressed by any server, app, or our nginx-proxy.

If we want to visit thay hostname by browser, the extra setting for etc/hosts is needed.

The nginx-proxy project supply some template setting, so you might able to get the IP of app containers and its VIRTUAL_HOST environment then append it to /etc/hosts file. But in such way this would be directly visit to node app server instead of proxy from nginx-proxy.

Without production level concern, I would suggest to append app domains in etc/hosts file at last line which is set by nginx-proxy, then it should work as you expected. Otherwise the work for hostname dynamic binding from nginx-proxy templates is necessary.

edited Aug 29, 2017 at 6:05

answered Aug 27, 2017 at 6:07

James Yang

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7 Comments

Mathias Over a year ago

check out the image of the reverse proxy. github.com/jwilder/nginx-proxy This image is searching in docker (thats why the docker socket is mounted) for services it can proxy. It also takes care of the dependencies to the containers

James Yang Over a year ago

From docker host: curl -H 'Host: node.app1.com' localhost should work as well. But if we must visit via http://node.app1.com, DNS setup should be necessary. Provided your DNS is setup to forward foo.bar.com to the host running nginx-proxy, the request will be routed to a container with the VIRTUAL_HOST env var set. - https://github.com/jwilder/nginx-proxy

Abhi Adr Over a year ago

it's working when i added entry in dns hosts file with the respective domain with out making any changes to compose file , but shouldn't it worked with out that .

Abhi Adr Over a year ago

@JamesYang before making entry to DNS hosts file i tried : From docker host: curl -H 'Host: node.app1.com' localhost which is working fine but , if i do not make any entry in hosts file and if i hit node.app1.com from browser request is not coming to nginx-proxy but with localhost if i try to hit request it's coming in nginx-proxy.

Abhi Adr Over a year ago

with node.app1.com in browser i can see the err server DNS address could not be found.

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nginx-proxy for more than one node app docker

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./app1/Dockerfile

./app2/app2.js

./app2/Dockerfile

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docker-compose.yml

./node-proxy/Dockerfile

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./app1/Dockerfile

./app2/app2.js

./app2/Dockerfile

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