Calico Docker BIRD Route Reflector image

Introduction

This directory contains the build scripts to create a Calico BIRD Route Reflector image that can be used to set up a cluster of Route Reflectors with a [Calico Docker][calico-docker] cluster of nodes.

The default target of the Makefile creates a Docker image called calico/routereflector, the Calico DockerHub repo creates a publically accessible image of the same name. If you just wish to use the current Route Reflector image, then you will not need to build the image locally.

For more details, refer to the main Calico documentation.

Route reflector cluster

When starting a cluster of route reflectors, the Calico BIRD Route Reflector takes care of creating a full mesh between all of the route reflectors in the cluster. When adding a new Route Reflector instance, add an entry into etcd. All Route Reflector instances watch for new Route Reflectors and update their peerings accordingly.

Route reflector peering with Calico Docker nodes

The Calico BIRD Route Reflector image hooks into the same etcd datastore used by the Calico Docker nodes to determine which nodes to peer with.

The peering between the Calico Docker nodes and each Route Reflector is entirely configured on the Calico Docker nodes (using [calicoctl][calicoctl]), and not through any additional Route Reflector configuration.

Using the Route Reflector image (with etcd datastore)

Starting up a Route Reflector

On your Route Reflector host, ensure you have [Docker v1.6][docker] or greater installed.

Run the following command to start the Route Reflector container image.

docker run -privileged -net=host -d                                \ 
           -e IP=<IPv4_RR>                                         \
           [-e IP6=<IPv6_RR>]                                      \
           -e ETCD_ENDPOINTS=<http://ETCD_IP:PORT>                 \
           calico/routereflector

Where:

[] indicates an optional parameter
<IPv4_RR> is the IPv4 address of the RR host (the BIRD instance binds to the hosts IPv4 address)
<IPv6_RR> is the optional IPv6 address of the RR host (the BIRD6 instance binds to the hosts IPv6 address)
<ETCD_IP:PORT> is the colon separated IPv4 address and port of an etcd node in the etcd cluster.

Adding the Route Reflector into etcd

Add an entry in etcd for this Route Reflector. This tells the Route Reflector to participate in peering, and provides enough information to allow the Route Reflector instances to automatically form a full BGP mesh.

The configuration for the Route Reflector is stored for IPv4 at:

/calico/bgp/v1/rr_v4/<RR IPv4 address>

and IPv6 at:

/calico/bgp/v1/rr_v6/<RR IPv6 address>

In all cases, the data is a JSON blob in the form:

    {
      "ip": "<IP address of BGP Peer>",
      "cluster_id": "<Cluster ID for this RR (see notes)>"
    }

To add this entry into etcd, you could use the following commands:

# IPv4 entries
curl -L http://<ETCD_IP:PORT>:2379/v2/keys/calico/bgp/v1/rr_v4/<IPv4_RR> -XPUT -d value="{\"ip\":\"<IPv4_RR>\",\"cluster_id\":\"<CLUSTER_ID>\"}"

# IPv6 entries
curl -L http://<ETCD_IP:PORT>:2379/v2/keys/calico/bgp/v1/rr_v6/<IPv6_RR> -XPUT -d value="{\"ip\":\"<IPv6_RR>\",\"cluster_id\":\"<CLUSTER_ID>\"}"

See below for details about large networks and the use and format of the cluster ID.

Repeat the above instructions for every Route Reflector in the cluster.

Route Reflector with TLS/SSL Etcd

If you are running secure etcd, you will need to pass in additional options and set environment variables for the certificate and key files associated with your etcd instance.

When starting the Route Reflector container image, you need to mount the certificate files and environment variable filepaths for each file:

docker run --privileged --net=host -d                              \
           -e IP=<IPv4_RR>                                         \
           [-e IP6=<IPv6_RR>]                                      \
           -e ETCD_ENDPOINTS=<https://ETCD_IP:PORT>                \
           -v <FULL_PATH_TO_CERT_DIR>:<MOUNT_DIR>                  \
           -e ETCD_CA_CERT_FILE=<MOUNT_DIR>/<CA_FILE>              \
           -e ETCD_CERT_FILE=<MOUNT_DIR>/<CERT_FILE>               \
           -e ETCD_KEY_FILE=<MOUNT_DIR>/<KEY_FILE>                 \
           calico/routereflector

Where <FULL_PATH_TO_CERT_DIR> is a directory on the host that contains the certificate files (you can mount multiple directories with additional -v <DIR> parameters if they are in separate directories, but be sure to choose different <MOUNT_DIR> locations if this is the case).

You will also need to pass the certificate and key files as parameters in the curl statement when adding entries:

# IPv4 entries
curl --cacert <path_to_ca_cert> --cert <path_to_cert> --key <path_to_key> -L https://<ETCD_IP:PORT>:2379/v2/keys/calico/bgp/v1/rr_v4/<IPv4_RR> -XPUT -d value="{\"ip\":\"<IPv4_RR>\",\"cluster_id\":\"<CLUSTER_ID>\"}"
# IPv6 entries
curl --cacert <path_to_ca_cert> --cert <path_to_cert> --key <path_to_key> -L https://<ETCD_IP:PORT>:2379/v2/keys/calico/bgp/v1/rr_v6/<IPv6_RR> -XPUT -d value="{\"ip\":\"<IPv6_RR>\",\"cluster_id\":\"<CLUSTER_ID>\"}"

Using the Route Reflector image (with Kubernetes API datastore)

If you are using Kuberenetes as the datastore for Calico, the routereflector image does support this, but only for a single route reflector. It is not possible with this image to set up a cluster of route reflectors.

Starting up the Route Reflector