Nextcloud with podman rootless containers and user systemd services. Part II - Nextcloud pod

Jan 28, 2021 08:30 · 733 words · 4 minute read

Running a rootless Nextcloud pod 🔗

Instead of running Nextcloud as independant containers, I’ve decided to leverage one of the multiple podman features which is being able to run multiple containers as a pod (like a kubernetes pod!)

The main benefit to me of doing so is they they use a single network namespace, meaning all the containers running in the same pod can reach each other using localhost and you only need to expose the web interface. So for instance the mysql or redis traffic doesn’t leave the pod. Pretty cool huh?

First thing first, I created a folder to host some data, scripts, etc. as:

export PODNAME="nextcloud"
mkdir -p ~/containers/nextcloud/{db,nginx,html}

Where:

  • db will host the database
  • nginx contains the custom nginx.conf file
  • html will host the Nextcloud content

And created an empty pod exposing port 8080/tcp only

podman pod create --hostname ${PODNAME} --name ${PODNAME} -p 8080:80

Next step… start adding containers by running them with the --pod flag.

MariaDB container 🔗

podman run \
  -d --restart=always --pod=${PODNAME} \
  -e MYSQL_ROOT_PASSWORD="myrootpass" \
  -e MYSQL_DATABASE="nextcloud" \
  -e MYSQL_USER="nextcloud" \
  -e MYSQL_PASSWORD="mynextcloudpass" \
  -v ${HOME}/containers/nextcloud/db:/var/lib/mysql:Z \
  --name=${PODNAME}-db docker.io/library/mariadb:latest \
  --transaction-isolation=READ-COMMITTED --binlog-format=ROW

As you careful reader has probably observed, I didn’t used the -p flag to expose the container to the outside world… because running it in a pod makes it reachable as localhost 3306/tcp port.

Selinux disclaimer 🔗

The :z and :Z flags are important if you use SElinux… because you use SElinux right ?

Quoting the podman-run man :

To change a label in the container context, you can add either of two suffixes :z or :Z to the volume mount. These suffixes tell Podman to relabel file objects on the shared volumes. The z option tells Podman that two containers share the volume content. As a result, Podman labels the content with a shared content label. Shared volume labels allow all containers to read/write content. The Z option tells Podman to label the content with a private unshared label.

Redis 🔗

podman run \
  -d --restart=always --pod=${PODNAME} \
  --name=${PODNAME}-redis docker.io/library/redis:alpine \
  redis-server --requirepass yourpassword

It will listen into the 6379/tcp port ONLY within the pod.

Nextcloud App 🔗

podman run \
  -d --restart=always --pod=${PODNAME} \
  -e REDIS_HOST="localhost" \
  -e REDIS_HOST_PASSWORD="yourpassword" \
  -e MYSQL_HOST="localhost" \
  -e MYSQL_USER="nextcloud" \
  -e MYSQL_PASSWORD="mynextcloudpass" \
  -e MYSQL_DATABASE="nextcloud" \
  -v ${HOME}/containers/nextcloud/html:/var/www/html:z \
  --name=${PODNAME}-app docker.io/library/nextcloud:fpm-alpine

It will listen into the 9000/tcp port ONLY within the pod.

Nextcloud Cron 🔗

podman run \
  -d --restart=always --pod=${PODNAME} \
  -v ${HOME}/containers/nextcloud/html:/var/www/html:z \
  --entrypoint=/cron.sh \
  --name=${PODNAME}-cron docker.io/library/nextcloud:fpm-alpine

Nginx 🔗

I’ve copied the ‘official’ nginx.conf to the proper location:

curl -o ~/containers/nextcloud/nginx/nginx.conf https://raw.githubusercontent.com/nextcloud/docker/master/.examples/docker-compose/with-nginx-proxy/mariadb-cron-redis/fpm/web/nginx.conf 

Then to run the container:

podman run \
  -d --restart=always --pod=${PODNAME} \
  -v ${HOME}/containers/nextcloud/html:/var/www/html:ro,z \
  -v ${HOME}/containers/nextcloud/nginx/nginx.conf:/etc/nginx/nginx.conf:ro,Z \
  --name=${PODNAME}-nginx docker.io/library/nginx:alpine

It will listen into the 80/tcp port… and as the pod expose that port as 8080/tcp in the host, you will be able to reach the app!

Nextcloud installation 🔗

Once all the pods are up and running, it is time to tweak the Nextcloud default deployment to fit our environment:

  • Connect to the nextcloud-app container:
podman exec -it -u www-data nextcloud-app /bin/sh
  • Perform the installation:
php occ maintenance:install \
  --database "mysql" \
  --database-host "127.0.0.1" \
  --database-name "nextcloud" \
  --database-user "nextcloud" \
  --database-pass "mynextcloudpass" \
  --admin-pass "password" \
  --data-dir "/var/www/html"
  • Configure a few settings such as the trusted domains:
php occ config:system:set \
  trusted_domains 1 --value=192.168.1.98
php occ config:system:set \
  trusted_domains 2 --value=nextcloud.example.com
php occ config:system:set \
  overwrite.cli.url --value "https://nextcloud.example.com"
php occ config:system:set \
  overwriteprotocol --value "https"

NextCloud resets the data directory permissions to 770, but nginx requires to access that folder, otherwise it complains about file not found. I tried to use --group-add flags to force group allocation of the user running both nginx and nextcloud but they run as root and then they change to a different user (www-data and nginx) so the group is not inherited…

php occ config:system:set \
  check_data_directory_permissions --value="false" --type=boolean

The reason behind the directory permissions is here .

sudo chmod 775 ~/containers/nextcloud/html
podman pod restart nextcloud

Firewall 🔗

In order to be able to reach the pod from the outside world, you just need to open the 8080/tcp port as:

sudo firewall-cmd --add-port=8080/tcp
sudo firewall-cmd --add-port=8080/tcp --permanent

At this point, you have a proper Nextcloud pod running in your box that you can start using!!!

Next post 🔗

In the next post I will explain how I managed to fix some issues I found while using Nextcloud and NFS.

You can read it here