Install Portainer Agent with Docker Swarm on Linux

Introduction

Portainer uses the Portainer Agent container to communicate with the Portainer Server instance and provide access to the node's resources. This document will outline how to install the Portainer Agent on your node and how to connect to it from your Portainer Server instance. If you do not have a working Portainer Server instance yet, please refer to the Portainer Server installation guide first.

To get started, you will need:

• The latest version of Docker installed and working.

• Swarm mode enabled and working, including the overlay network for the swarm service communication.

• sudo access on the manager node of your swarm cluster.

• The manager and worker nodes must be able to communicate with each other over port 9001. In addition, the Portainer Server installation must be able to reach the nodes on port 9001. If this is not possible, we advise looking at the Edge Agent instead.

The installation instructions also make the following assumptions about your environment:

• Your environment meets our requirements. While Portainer may work with other configurations, it may require configuration changes or have limited functionality.

• You are accessing Docker via Unix sockets. Connecting via TCP is not supported in Docker Swarm.

• SELinux is disabled on the machine running Docker.

• Docker is running as root. Portainer with rootless Docker has some limitations, and requires additional configuration.

• If your nodes are using DNS records to communicate, that all records are resolvable across the cluster.

• You have not set a custom AGENT_SECRET on your Portainer Server instance. If you have, you will need to provide that secret to your agent by adding it to the stack file:

  environment:

  - AGENT_SECRET: yoursecret

Deploying the Agent

Only do this once for your environment, regardless of how many nodes are in the cluster. You do not need to add each node as an individual environment in Portainer. Adding just one node (we recommend the manager node) will allow Portainer to manage the entire cluster. Adding each node as a separate environment will also consume more of your licensed node count than you may expect.

From the menu select Environments then click Add environment.

Next, select Docker as the environment type then click Start Wizard. Select the Agent option and the Linux tab. Copy the command, then run it on the manager node of your Docker Swarm cluster.

You must run the command on the Docker Swarm cluster before entering the environment details.

The deployment command will return something similar to:

Creating network portainer-agent_portainer_agent
Creating service portainer-agent_agent

To validate the Agent is running, you can run the following command:

 docker service ls

the result of which should look something like this:

ID                  NAME                    MODE                REPLICAS            IMAGE                    PORTS
tshb6ee2710s        portainer-agent_agent   global              1/1                 portainer/agent:latest

Once the Portainer Agent has been successfully deployed on the cluster, you can complete the rest of the environment configuration.

Finishing the configuration

Once the Agent is running on the Docker Swarm cluster, enter the environment details using the table below as a guide.

Only do this once for your environment, regardless of how many nodes are in the cluster. You do not need to add each node as an individual environment in Portainer. Adding just one node (we recommend the manager node) will allow Portainer to manage the entire cluster. Adding each node as a separate environment will also consume more of your licensed node count than you may expect.

Field	Overview
Name	Give the environment a descriptive name.
Environment address	Enter the IP or DNS name at which the Portainer Server instance can reach the environment along with the port (9001).

As an optional step you can expand the More settings section and categorize the environment by adding it to a group or tagging it for better searchability.

When you're ready, click Connect. If you have other environments to configure click Next to proceed, otherwise click Close to return to the list of environments.