OS: CentOS 8
Docker Containers: drupal:latest & mariadb:latest
I've been trying to learn Docker containerization by making a Drupal container connect to a MariaDB container for almost two weeks now, and couldn't figure out what was wrong.
I just ran:
systemctl stop firewalld and it finally worked! Yes, I know this is a bad thing to do, which is why I'm here. None of the tutorials I've found said anything about opening firewall ports for docker.
I did find a few online tutorials, specifically for opening docker services, but none of them worked. Most of them told me to run:
firewall-cmd --permanent --zone=trusted --add-interface=docker0, but that didn't work. It was only when I shut down the firewall completely that the install actually started working.
Can any one please explain what I need to run to keep the firewall running, but allowing the containers to communicate with each other? It would also help if you gave a brief explanation as to what each command is doing, as firewall rules are still kind of cryptic to me.
Here's what I've run to set this up:
docker network create -d bridge meow
docker run \
-e MYSQL_ROOT_PASSWORD=admin \
-e MYSQL_DATABASE=drupal \
-e MYSQL_USER=drupal \
-e MYSQL_PASSWORD=drupal \
--network meow \
--name mariadb \
-d mariadb:latest
docker run \
-p 80:80 \
--network meow \
--name drupal \
-d drupal:latest
systemctl stop firewalld
Please note, I want to learn how docker works before I add new tools like docker-compose. So I may be trying to do this the hard way (I don't know yet), but I would just like to figure this out before I learn new things.
Thanks.
