How to access a Docker container without specifying its HTTP port? - docker

Question

I set up a Docker network with a db container, a nextcloud container, and a nginx container. I can access the nextcloud website with 'ip-adress':8080, but I want to access it without specifying port 8080. How can I do that?
This is my docker-compose.yml:
version: '2'
volumes:
nextcloud:
db:
services:
db:
image: mariadb
restart: always
command: --transaction-isolation=READ-COMMITTED --binlog-format=ROW
volumes:
- db:/var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=
- MYSQL_PASSWORD=
- MYSQL_DATABASE=nextcloud
- MYSQL_USER=nextcloud
app:
image: nextcloud:fpm
restart: always
links:
- db
volumes:
- nextcloud:/var/www/html
environment:
- MYSQL_PASSWORD=
- MYSQL_DATABASE=nextcloud
- MYSQL_USER=nextcloud
- MYSQL_HOST=db
web:
image: nginx
restart: always
ports:
- 8080:80
links:
- app
volumes:
- ./nginx.conf:/etc/nginx/nginx.conf:ro
volumes_from:
- app

Answer 1

What you want is to avoid having to specify the port when you request a URI. One way to do that is to use the default port for the protocol you are using (80 for HTTP, 443 for https, 21 for FTP, etc). Then rely on your client to automatically fallback to the default port.
In a Docker Compose configuration file, the syntax for exposing a port is defined as such: <host_port>:<container_port> (see the documentation). That means 8080:80 exposes port 80 from the container on your docker host on port 8080.
In your case, the service is exposing an HTTP server, which means you have to change it to the default port 80 in order to omit it. Update web.services.ports[0] from 8080:80 to 80:80, and you will be able to access nextcloud from 'ip-adress'.