Swarm Cluster
Initialize, join, unlock, and update a Docker Swarm cluster.
Use the Cluster page to create, join, or leave a Swarm in the selected environment. It is also where you unlock the cluster, rotate join tokens, and update the live Swarm spec.
Initialize a Swarm
Use this when the selected environment isn’t part of a Swarm yet.
- Open Swarm → Cluster.
- Under Initialize Cluster, optionally open Advanced settings and fill in the fields below.
- Click Initialize.
The defaults suit a local or single-network cluster. Change the advanced settings only when your network or security setup needs it.
| Field | What it does |
|---|---|
| Listen address | Address and port the Swarm manager listens on for cluster traffic. |
| Advertise address | Address other nodes use to reach this manager. Set it when the host has several network interfaces. |
| Swarm spec JSON | A full Swarm spec as a JSON object, for settings not covered by the other fields. |
| Auto-lock managers | Encrypts manager data so a restarted manager stays locked until you enter the unlock key. |
| Force new cluster | Creates a new single-manager cluster from this node’s existing Swarm state. Use it to recover a cluster that lost its managers. |
Arcane then shows the rest of the Swarm workspace for that environment.
Join an existing Swarm
Use this to add the selected environment to a cluster that is already running, as a manager or a worker.
- Open Swarm → Cluster.
- Under Join Existing Cluster, enter the remote manager addresses (comma separated), the join token, and optional listen and advertise addresses.
- Click Join.
Easy Join remote environments
When the selected environment is a Swarm manager, Easy Join adds other Remote Environments to its cluster without you copying manager addresses or join tokens.
Start it from Swarm → Cluster → Easy Join, or from a Remote Environment’s detail page or row menu. Only enabled, online environments not already linked to a node of this cluster are offered.
- Select each target environment.
- Choose worker or manager and an availability mode.
- Optionally set listen, advertise, or data-path addresses per target. Leave the manager addresses blank to use the ones Arcane finds in the cluster; any address you enter must be reachable from every selected host.
- Confirm.
The join tokens are never shown. Each target gets its own result in Join results, and a failed target doesn’t undo the others:
| Result | Meaning |
|---|---|
| Joined and verified | The host joined and Arcane linked the environment to its Swarm node. |
| Already a member and verified | The host was already in this cluster. Arcane linked it without rejoining. |
| Joined; verification is still pending | The host joined, but Arcane couldn’t confirm the node in time. Opening Nodes finishes the link later. |
A host that is active in a different cluster is rejected; Arcane doesn’t force it to leave.
Easy Join needs swarm:join on the manager and on every target. The Easy Join button on the Cluster page also needs swarm:nodes and swarm:unlock on the manager.
Leave a cluster
Click Leave Cluster to remove the selected node from the Swarm. Select Force leave if a normal leave fails.
Unlock a locked cluster
If Auto-lock managers is on and a manager restarted, the cluster stays locked until you unlock it.
- Open Swarm → Cluster.
- Enter the unlock key.
- Click Unlock.
Rotate join tokens and the unlock key
The Cluster page shows the worker join token, the manager join token, and the manager unlock key, and can rotate each of them. Treat them like passwords. Rotating one invalidates the old value.
Update the cluster spec
Under Update Swarm Spec, click Load current spec, edit the JSON, and click Update Spec. This changes live cluster scheduling and security settings, so only use it if you know the Docker Swarm setting you are changing.
Cluster actions need a Swarm manager environment and the matching permissions. See Docker Swarm for the permission rules.