How to Create a Macvlan Network in Docker Swarm

In a Docker Swarm environment, networking configurations play a critical role in ensuring that services communicate effectively. One such configuration is the Macvlan network, which allows containers to appear as physical devices on your network. This setup can be particularly useful for services that require direct access to a physical network. Here’s a step-by-step guide on how to create a Macvlan network in your Docker Swarm cluster.

Step 1: Define the Macvlan Network on the Master Node

The first step involves defining the Macvlan network on the master node of your Docker Swarm. This network will be used across the entire cluster. To create a Macvlan network, you’ll need to specify a subnet, gateway, parent interface, and make the network attachable. Here’s how you can do it:

docker network create -d macvlan \
  --subnet=192.168.0.0/24 \
  --gateway=192.168.0.1 \
  -o parent=eth0 \
  --attachable \
  swarm-macvlan

This command creates a Macvlan network named swarm-macvlan with a subnet of 192.168.0.0/24, a gateway of 192.168.0.1, and attaches it to the eth0 interface of your Docker host. The --attachable flag allows standalone containers to connect to the Macvlan network.

Step 2: Verify the Macvlan Network Creation

After creating the Macvlan network, it’s important to verify its existence and ensure it’s correctly set up. You can inspect the network details using:

docker network inspect swarm-macvlan

This command provides detailed information about the swarm-macvlan network, including its configuration and any connected containers.

To list all networks and confirm that your Macvlan network is among them, use:

docker network ls

This command lists all Docker networks available on your host, and you should see swarm-macvlan listed among them.

Conclusion

Creating a Macvlan network in Docker Swarm enhances your cluster’s networking capabilities, allowing containers to communicate more efficiently with external networks. By following the steps outlined above, you can successfully set up a Macvlan network and integrate it into your Docker Swarm environment. This setup is particularly beneficial for services that require direct access to the network, providing them with the necessary environment to operate effectively.