LuXeria Infrastructure Docker Compose Files

This repository contains the Docker Compose deployments used in our infrastructure. All deployments are found in /var/data/Deployments.

Host-mounted Volumes

When specifying the host part of a volumes section, please use one of the following two patterns:

• ./config:/var/app/config:ro: For read-only configuration files which can be committed to git. They will be stored in the same directory as the docker-compose.yaml file.
• ${LUX_VOLUMES:?}/data:/var/app/data: For application data that the container may write to, and for sensitive configuration (e.g. credentials). Those will be stored in a separate directory outside the git tree.

On our server, the LUX_VOLUMES environment is set to /var/data/Volumes in /etc/environment (for user sessions) and in the systemd service file below (for systemd). For local testing, you may set it to a different directory.

The :? part of ${LUX_VOLUMES:?} will make docker compose commands error out if the variable is not set.

Please do not use Docker external named volumes, as they are harder to inspect, backup and transfer between hosts.

Managing services via systemd

All deployments are managed via the docker-compose@ systemd service unit. Please make sure that the docker compose up command of a deployment does not depend on resources owned by other services, since this systemd unit starts all services in parallel.

To make sure a newly deployment is supervised by systemd after boot, run the following command (e.g. for a deployment stored in the foobar/ folder):

$ systemctl enable docker-compose@foobar.service

The service unit behind all of this is found in /etc/systemd/system/docker-compose@.service:

[Unit]
Description=%i service with docker compose
Requires=docker.service
After=docker.service

[Service]
Type=oneshot
RemainAfterExit=true
Environment=LUX_VOLUMES=/var/data/Volumes
WorkingDirectory=/var/data/Deployments/%i
ExecStart=/usr/bin/docker compose up -d --remove-orphans
ExecStop=/usr/bin/docker compose down
TimeoutStartSec=5m

[Install]
WantedBy=multi-user.target

Docker Configuration

The /etc/docker/daemon.json on the host looks as follows:

{
  "default-address-pools" : [
    {
      "base" : "172.18.0.0/16",
      "size" : 24
    }
  ],
  "log-driver": "journald"
}

Rationale

default-address-pools:

We use different default address pool to

1. avoid overlap with other routable subnets in the 172.16.0.0/12 range
2. use smaller default subnets (/24 instead of /16) to preserve IP space

You can still manually create docker networks outside of this default subnet using docker network create --ip-range.

log-driver:

Using journald for logging ensures logs are persistently stored independently of the Docker lifecycle. To inspect the logs for a particular container, run:

journalctl CONTAINER_NAME=foobar