This guide provides instructions for installing Calico and its prerequisites on a Mesos DC/OS cluster.

Prerequisites

Mesos Master and Agents

You will need to be running a cluster with at least one Mesos master and and at least one Mesos agent (though we recommend having two or more agents).

You can set up a cluster fairly easily by following the DC/OS Vagrant Install guide. It is important to note that if you install from this vagrant script, the Docker version on the machines will be insufficient, so you will need to upgrade to Docker 1.9 or above before launching the Calico service.

We currently support DC/OS 1.7 (with Mesos 0.28.1). We support Centos7 and CoreOS as operating systems for use with the Unified Containerizer and Docker Containerizer.

Etcd

Calico requires an etcd datastore. A service discovery URL is required to access the datastore, which can be configured in the Calico service’s Advanced Install options.

You can quickly spin up an etcd cluster using ths DCOS Universe package as follows (Calico is configured to use the default service discovery URL in this install, so you won’t need to edit this URL in the Calico config):

• Go to the Universe tab in your DC/OS UI.
• Find the etcd package
• Click the Install button
• (Optional) choose Advanced Installation from the pop-up window.
  • In non-production environments used for testing, you might have extremely limited resources available on each host (this is certainly the case for the DCOS vagrant install), so you may want to set all of the mem options to use 50MB or lower (this includes mem and mem-limit).
• Choose Review and Install
• Double-check configuration then click Install.

You can check the status of etcd by visiting the Services tab. You can install Calico once etcd appears with a status of Healthy (note that this could take a few minutes).

Mesos-DNS

Calico is compatible with Mesos-DNS, but requires a minor configuration change to preferentially resolve to a container’s IP address instead of resolving to its host’s. Follow these steps on each master in your cluster to allow containers to be resolvable via their containerized IP:

1. Open /opt/mesosphere/etc/mesos-dns.json with any text editor.
2. Find the line that reads: "IPSources": ["host", "netinfo"]
3. Reverse the order of those two fields: "IPSources": ["netinfo", "host"]
4. Restart mesos-dns with: sudo systemctl restart dcos-mesos-dns

Install Calico

You can easily install Calico from within the DCOS UI.

Install Calico Package

You can now install the Calico package from the Universe tab. To start the install:

• Go to the Universe tab
• Find the Calico package
• Click the Install button then choose Advanced Installation in the pop-up window.

At this point you have a few options:

In non-production environments used for testing, you might have extremely limited resources available on each host (this is certainly the case for the DCOS vagrant install), so you may want to set all of the mem options to use 50MB or lower, as seen in the image below. This will ensure that smaller tasks with low memory requirements will be scheduled immediately. The changes include modifying mem-limit-framework, mem-limit-install, mem-limit-etcd-proxy, mem-limit-node, and mem-limit-libnetwork.

You could also speed up the install by increasing max-concurrent-restarts, allowing Calico to restart the Mesos agent and Docker services on more than one agent at a time. NOTE: This is not generally recommended, but it is fine if you’re bringing up a new system.

After configuring the options:

Click Review and Install, double-check your configuration settings, then choose Install.

Calico will now begin installation on your cluster.

Check Calico Status

It will take a few minutes for Calico to finish installing on your cluster.

Calico runs the following tasks on each agent:

• Configure an Etcd proxy
• Install Docker multi-host networking
• Install Mesos net-modules
• Run the calico-node Docker image
• Run the calico-libnetwork Docker image

You can check the status of each process on each agent by visiting Calico’s status web interface:

• Go to the Services tab
• Find Calico in the list of running services (note that it may take a few minutes for Calico to appear).
• Once the Calico service is Healthy, click the square pop-out icon next to the service name to open the Calico status page in a new tab.

You should see a page that looks like the following:

The webpage may fail to load initially since the Calico service restarts the Docker and Mesos agent services, which will cause a restart of the Calico framework when it happens on the same agent. This is expected and nothing to be concerned about. Once the status page is running, you will see a table where each row represents an agent, including statuses for each of the Calico components installed.

Next Steps

Once all of the Calico components are installed and running, you can start launching tasks with your Mesos cluster.

Get started by checking out our user guides for the Docker Containerizer or the Unified Containerizer, or to learn more about the differences between the two containerizers, check out our Mesos README.