What Container Manager Is and Why It Matters
Docker containers on a Synology NAS mean you can install and run modern server applications in isolated, portable environments, managed through Synology’s Container Manager interface that replaces the older Docker package while still using standard Docker images and documentation. This setup is for home users and small teams who want flexible services without learning command-line Docker, but you should be comfortable with your NAS’s DSM interface and basic file paths before diving in. The real prerequisite is having Container Manager installed from Package Center, which automatically creates a shared docker folder and migrates any existing Docker containers so they survive the transition without extra work. Once that is in place, you get tabs for Projects, Containers, Images, Registry, Networks, and Logs, giving you a clear overview of what’s running and where to configure it.
Setting Up Container Manager and Understanding the Interface
Before you build anything, it helps to know where everything lives. Container Manager is installed from Package Center and replaces the old Docker package rather than sitting alongside it, so your previous containers and images remain intact. Installing it also creates the shared docker folder, which is where all your container projects and data should live. When you open Container Manager, you land on the Overview tab, which shows resource usage and running services, but you can mostly ignore this and focus on the others. The Project tab is where Docker Compose NAS setups happen; the Container tab lists individual containers built through the GUI; Image and Registry handle downloading and viewing images; Network manages container networking, including macvlan interfaces created over SSH; and Log shows events for the package itself. Once you’re familiar with these, the rest of the workflow feels much less mysterious.
Step-by-Step: Creating a Docker Compose Project on Your NAS
On Synology, the Project tab is the easiest way to deploy Docker containers with Docker Compose without command-line expertise. You use the same Compose files you’d see on Docker Hub, but feed them into Container Manager instead of running them over SSH.
- In File Station, open the docker shared folder and create a dedicated subfolder for this container; Container Manager creates docker for you, and every project should live under it.
- Open Container Manager, go to the Project tab, click Create, give the project a meaningful name, and set the path to the folder you just made.
- Choose Create docker-compose.yml and paste the Compose example from the container’s Docker Hub documentation, or upload an existing docker-compose.yml; each container gets its own folder and file.
- Edit the Compose file before saving: set passwords, time zone, ports, and, most importantly, fix volume paths from relative to absolute Synology paths. Then create the project so Container Manager can build it.
Container Manager reads the same Compose syntax you’d use anywhere else, but volume mapping is where many beginners trip up. Once the paths are correct and the project starts cleanly, Docker containers on Synology behave like they do on any other machine; you can stop, start, and update them from the Project tab while keeping the configuration in a single, portable file. A Compose-based setup is easier to move to another host later and simpler to restore if you ever need to rebuild.
Volumes, Networking, and Persistence: Avoiding the Gotchas
Volumes are the main gotcha. Docker documentation often uses relative paths like ./etc-pihole:/etc/pihole, but those do not work on a Synology NAS and cause more failed containers than anything else in Container Manager. You must treat every volume line as local folder : container folder, replacing the left side with an absolute NAS path that includes the volume number, usually starting with /volume1/docker/[project]/…. Container Manager will not create these subfolders for you, so every directory referenced on the left side has to exist in File Station before the project starts, or it fails. These mounted folders hold all of your personal data for each container and are the key locations you should back up because everything else is configuration that can be rebuilt. For networking, use the Network tab to review bridge or host setups; macvlan special cases still require SSH to create, but Container Manager can manage them once they exist.
Troubleshooting Common Synology Container Problems and Final Takeaways
When a Project fails to start, the error is almost always a missing folder or a port conflict. If that happens, first confirm that every local path in the Compose file points to a folder that exists under docker in File Station; if any are missing, create them and re-run the project. Then check port mappings: DSM already uses port 80 for its own reverse proxy, so binding containers to port 80 on the host will collide. Pick alternative ports and adjust your Compose file accordingly. If you need advanced networking such as macvlan, you still have to SSH into the NAS and enable SSH in Control Panel under Terminal & SNMP first. Once your paths and ports are clean, Container Manager builds the project and your containers start reliably. The payoff is worth the initial learning curve: a tidy, Compose-driven library of services you can export, back up, and recreate elsewhere with minimal effort.
