Calico Route Reflector Init

An init container that configures a Kubernetes node to act as a Calico BGP route reflector.

Overview

The container performs two tasks that automates the configuration of a node for route reflection:

1. Applies a label to the node which should be used in BGPPeer resources to indicate which nodes should (or should not) peer with this node.
2. Applies an annotation to the node specifying a cluster identifier, indicating that this node is a route reflector.

For a detailed explanation of how route reflectors are configured, see configuring in-cluster route reflectors.

Usage

This should be used as an init container for the calico-node daemonset that will be acting as both a calico-node and a route reflector, thus we recommend two sepearate daemonsets of calico-node:

• One that targets nodes intended to be route reflectors (i.e. masters).
• One that targets the rest of the nodes (i.e. workers).

Example

In this example, we're configuring the masters to be our route reflectors, as part of the choose and labels nodes section of Calico the hard way.

kind: DaemonSet
apiVersion: apps/v1
metadata:
  name: calico-node-master
  namespace: kube-system
spec:
  ...
  template:
    ...
    spec:
      ...
      nodeSelector:
        # Run calico-node-master on masters only.
        node-role.kubernetes.io/master: ""
      tolerations:
        - key: node-role.kubernetes.io/master
          effect: NoSchedule
      initContainers:
        - name: configure-route-reflector
          image: zappi/calico-route-reflector-init:0.1.0
          env:
            # Use the Downward API set the node name.
            - name: KUBERNETES_NODE_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: CALICO_ROUTE_REFLECTOR_LABEL_NAME
              value: "calico-route-reflector"
            - name: CALICO_ROUTE_REFLECTOR_CLUSTER_ID
              value: "1.1.1.1"

Since our masters are already running their own calico-node, we must ensure that our second daemonset only runs on worker nodes.

kind: DaemonSet
apiVersion: apps/v1
metadata:
  name: calico-node
  namespace: kube-system
  ...
spec:
  ...
  template:
    ...
    spec:
      ...
      nodeSelector:
        # Run calico-node on workers only.
        node-role.kubernetes.io/node: ""

Once the two daemonsets are up and running, you can move on to the next step, configuring your peering.

Environment Variables

Name	Description	Example	Required
KUBERNETES_NODE_NAME	The name of the node to be labelled and annotated.	ip-10-24-101-78.ec2.internal	Yes
CALICO_ROUTE_REFLECTOR_LABEL_NAME	The name of the label to be used for peering configuration.	calico-route-reflector	Yes
CALICO_ROUTE_REFLECTOR_LABEL_VALUE	The value of the label to be used for peering configuration.	true	No
CALICO_ROUTE_REFLECTOR_CLUSTER_ID	The cluster identifier to use when annotating the node as a route reflector.	224.0.0.1	Yes

Compatibility

We should be able to support Calico 3.3.0 and later.