Docker-compose can't start apache server - apache

Question

When i'm running sudo docker-compose up inside my dir, i get this error. I'm trying to make a container, that host a php website, where you can do whoami on it.
Thanks
(13)Permission denied: AH00072: make_sock: could not bind to address 0.0.0.0:80
| no listening sockets available, shutting down
| AH00015: Unable to open logs
Dockerfile:
FROM ubuntu:16.04
RUN apt update
RUN apt install -y apache2 php libapache2-mod-php
RUN useradd -d /home/cp/ -m -s /bin/nologin cp
WORKDIR /home/cp
COPY source .
USER cp
ENTRYPOINT service apache2 start && /bin/bash
docker-compose.yml
version: '2'
services:
filebrowser:
build: .
ports:
- '8000:80'
stdin_open: true
tty: true
volumes:
- ./source:/var/www/html
- ./logs:/var/log/apache2

Answer 1

There's a long-standing general rule in Unix-like operating systems that only the root user can open "low" ports 0-1023. Since you're trying to run Apache on the default HTTP port 80, but you're running it as a non-root user, you're getting the "permission denied" error you see.
The absolute easiest answer here is to use a prebuilt image that has PHP and Apache preinstalled. The Docker Hub php image includes a variant of this. You can use a simpler Dockerfile:
FROM php:7.4-apache
# Has Apache, mod-php preinstalled and a correct CMD already,
# so the only thing you need to do is
COPY source /var/www/html
# If you want to run as a non-root user, you can specify
RUN useradd -r -U cp
ENV APACHE_RUN_USER cp
ENV APACHE_RUN_GROUP cp
With the matching docker-compose.yml
version: '3' # version 2 vs 3 doesn't really matter
services:
filebrowser:
build: .
ports:
- '8000:80'
volumes:
- ./logs:/var/log/apache2
If you want to build things up from scratch, the next easiest option would be the Apache User directive: have your container start as root (so it can bind to port 80) but then instruct Apache to switch to the unprivileged user once it's started up. The standard php:...-apache image has an option to do this on its own which I've shown above.