Docker Swarm (deprecated)

Coolify v5 will replace Docker Swarm support with native Docker Compose replicas and Coolify's own scaling solution. Until that replacement is available, use multi-server deployments with an external load balancer for new infrastructure that must run across servers.

Existing Coolify v4 deployments

Coolify v4 keeps the existing Swarm controls so you can operate a deployment while planning its replacement.

On a server's Swarm page, Coolify identifies the server as either a Swarm manager or a Swarm worker. A node cannot be marked as both roles in the Coolify interface.

For an application deployed to a Swarm destination, Swarm Configuration includes:

• Replicas for the number of application tasks
• Only Start on Worker nodes to prevent tasks from starting on manager nodes
• Custom Placement Constraints for Docker Swarm placement rules

These settings do not create the Swarm cluster. The manager and worker nodes must already belong to a working Docker Swarm.

Registry and storage requirements

An application deployed to a Swarm destination must have Docker Image configured. The manager pushes the built image to that registry, and every node that may run the application must be able to pull it.

Authenticate the configured server user to the registry on the manager and worker nodes. See Docker registries.

Local Docker volumes belong to one node. If a Swarm task can move between workers, use storage that is available from every eligible node, such as a shared network filesystem or an external storage service supported by the application.

Check an existing cluster

Run the following command on a manager node:

docker node ls

Confirm that:

• one manager reports Leader in MANAGER STATUS
• every required manager and worker reports Ready in STATUS
• each node that may run the application reports Active in AVAILABILITY

Then deploy the application from Coolify and verify the desired task count on a manager node:

docker service ls

The value under REPLICAS should reach the configured replica count. Inspect the service with docker service ps <service-name> when a task does not start.

Move away from Docker Swarm

Plan the replacement before upgrading to Coolify v5. Record the application's image, environment variables, domains, health check, storage, networks, and placement requirements. Then deploy the application to standalone servers and place a load balancer in front of them.

Test the replacement through its public domain before removing the Swarm service. Keep the existing Coolify v4 deployment available until the new setup passes application, data, and failover checks.