docker - how to reach another container from a dockerised nginx -

i have nginx in docker container, , nodejs webapp in docker container. nodejs server reachable host server on port 8080.

the nginx docker container listening port 80 (will certificate later, first base must working).

and want subdomain forwarded 8080 nodejs app. lets app1.example.com

from outside can reach app te server ip (or hostname) , port 8080 not on app1.example.com. , work on app1.example.com:8080 (i have opened port 8080 on host server).

i bad gateway nginx message when approaching app1.example.com in first nginx container, how host server proxy pass port 8080 of host server (and not port 8080 of nginx container). looking reverse expose syntax.

the main problem is, of course if use ip , port 127.0.0.1:8080 try on nginx container.... how let nginx container route host 127.0.0.1:8080?

i have tried 0.0.0.0 , defining upstream, been googling lot, , have tried lot of configurations... not yet found working one....

edit found out, command of docker might help:

sudo docker network inspect bridge 

this shows ip address used inside cotainers (in case 172.17..0.2), not sure address stays same every time docker restart... (e.g. server reboot)

edit followning alkaline answer have (but still not working):

my docker-compose.yml file:

version: "2" services:   nginx:     container_name: nginx     image: nginx_img     build: ../docker-nginx-1/     ports:       - "80:80"     networks:       - backbone   nodejs:     container_name: nodejs     image: merites/docker-simple-node-server     build: ../docker-simple-node-server/     networks:     - backbone     expose:      - 8080   networks:     backbone:       driver: bridge 

and nginx (skipped incluse in conf.d folder simplicity):

worker_processes 1;

events { worker_connections 1024; }

http {    sendfile on;    upstream upsrv {       server nodejs:8080;   }    server {      listen 80;     server_name  app1.example.com;      location / {         proxy_pass http://upsrv;     }    } } 

edit 31-08-2016

this migth problem, name not backbone, called after folder started srevice from:

sudo docker network ls 

out puts:

network id          name                       driver              scope 1167c2b0ec31        bridge                     bridge              local                d06ffaf26fe2        dockerservices1_backbone   bridge              local                5e4ec13d790a        host                       host                local                7d1f8c32f259        none                       null                local  

edit 01-09-2016

it might caused way have nginx docker container setup?

this docker file used:

############################################################ # dockerfile build nginx installed containers # based on ubuntu ############################################################  # set base image ubuntu ubuntu  # file author / maintainer maintainer maintaner name  # install nginx  # add application repository url default sources # run echo "deb http://archive.ubuntu.com/ubuntu/ raring main     universe"     >> /etc/apt/sources.list  # update repository run apt-get update  # install necessary tools run apt-get install -y nano wget dialog net-tools  # download , install nginx run apt-get install -y nginx    # remove default nginx configuration file run rm -v /etc/nginx/nginx.conf  # copy configuration file current directory add nginx.conf /etc/nginx/  # append "daemon off;" beginning of configuration run echo "daemon off;" >> /etc/nginx/nginx.conf  # expose ports expose 80  # set default command execute # when creating new container cmd service nginx start 

my final solution 1th sept. 2016

i used compose file now:

version: "2" services:     nginx:       image: nginx       container_name: nginx       volumes:         - ./nginx-configs:/etc/nginx/conf.d       ports:         - "80:80"       networks:         - backbone     nodejs:       container_name: nodejs       image: merites/docker-simple-node-server       build: ../docker-simple-node-server/       networks:         - backbone       expose:          - 8080 networks:   backbone:     driver: bridge 

in project folder, wich run docker-compose -d, added folder named nginx-configs. folder 'override' files in nginx container named /etc/nginx/conf.d

therefor copied default.cfg nginx container before added volume mount. using command:

docker exec -t -i container_name /bin/bash

and cat /etc/nginx/conf.d/default.conf

and added same default.conf in project folder nginx configs.

besides default added app1.conf content:

upstream upsrv1 {     server nodejs:8080; }  server {      listen 80;     server_name  app1.example.com;       location / {         proxy_pass http://upsrv1;     }  } 

this way, can add second app... third , on.

so basics working now...

here's best practice. expose port 80 outside of host. nodejs app can in private network accessible through nginx.

version: "2" services:     nginx:       ...       ports:         - "80:80"       networks:         - backbone     nodejs:       ...       networks:         - backbone       expose:          - 8080  networks:   backbone:     driver: bridge 

in nginx.conf file, upstream servers can listed nodejs:8080. docker daemon resolve correct internal ip.