Swarm Cluster

Create, join, leave, unlock, and tune a Swarm from the Cluster page. It lists every environment you can read with its Swarm role (Manager, Worker, or Not initialized) and the cluster ID for managers. Click Inspect on a row to open that environment’s cluster panel.

An environment outside a Swarm offers initialization and join options.

×

An environment outside a Swarm offers initialization and join options.

Initialize a Swarm

Use this when an environment isn’t in a Swarm yet. Arcane then includes it in the rest of the Swarm workspace.

1. Open Swarm → Cluster and click Inspect on the environment.
2. Under Initialize Cluster, optionally open Advanced settings. The defaults suit a local or single-network cluster.
3. Click Initialize.

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.

Join an existing Swarm

To add an environment to a running cluster as a manager or worker:

1. Open Swarm → Cluster and click Inspect on the environment.
2. Under Join Existing Cluster, enter the remote manager addresses (comma separated), the join token, and optional listen and advertise addresses.
3. Click Join.

Easy Join remote environments

Easy Join adds other Remote Environments to a manager’s cluster without copying addresses or join tokens. Start it from Easy Join on a manager’s row under Swarm → Cluster, 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.

1. Select each target, then choose worker or manager and an availability mode.
2. Optionally set listen, advertise, or data-path addresses per target. Blank manager addresses use the ones Arcane finds in the cluster; any you enter must be reachable from every selected host.
3. Confirm.

Join tokens are never shown. Each target gets its own result in Join results, and one failure 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 active in a different cluster is rejected; Arcane doesn’t force it to leave. Easy Join needs swarm:join on the manager and every target. The Cluster page’s Easy Join button also needs swarm:nodes and swarm:unlock on the manager.

Leave a cluster

In the cluster panel, click Leave Cluster to remove that node. Select Force leave if a normal leave fails.

Unlock a locked cluster

With Auto-lock managers on, a restarted manager keeps the cluster locked until you unlock it. Open Swarm → Cluster, click Inspect on a manager, enter the unlock key, and click Unlock.

Rotate join tokens and the unlock key

A manager’s cluster panel shows and can rotate the worker join token, manager join token, and manager unlock key. 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 scheduling and security settings, so only use it if you know the Docker Swarm setting you’re changing.

Cluster actions need a Swarm manager environment and matching permissions. See Docker Swarm for the rules.