meshrr

Introduction

meshrr is a demonstration-grade scale-out, hierarchically-capable, BGP route reflection methodology using Juniper cRPD and intended for deployment on Kubernetes.

At this time and in the project's raw form, meshrr should not be considered for production environments. Sufficient testing, error handling, and routing daemon configuration best practices have not been implemented. Community contributions to improve these areas are appreciated.

• meshrr
  • Introduction
  • Instructions
    • Prerequisites
    • Usage
    • Environment Variables
  • Containers
  • BGP Group Types
  • Examples
  • Example Commands

Instructions

Prerequisites

1. An operational Kubernetes cluster with sufficient resources for the topology you wish to build.
2. The cRPD software. The current tested version is 23.2R1.13. The software must be available via a private repository or preloaded onto all nodes it may be run on. If using k3s, this can be accomplished with k3s ctr images import junos-routing-crpd-docker-amd64-23.2R1.13.tar.
   • If the import fails, you may need to convert the tarfile into a format that can be imported. You can do so with

     docker load -i junos-routing-crpd-docker-amd64-23.2R1.13.tgz \
      && docker image tag crpd:23.2R1.13 localhost/juniper/crpd:23.2R1.13 \
      && docker image save localhost/juniper/crpd:23.2R1.13 --output=junos-routing-crpd-docker-amd64-23.2R1.13.tar 

3. A cRPD license for the number of nodes you wish to deploy. At the time of writing, Juniper offers free trial licenses. Standard licenses are limited to 16 BGP peers and 4M RIB entries.

Usage

1. (If required) copy a configuration file template from the default templates and edit it to your liking.

2. Either:

   1. Pick an example topology from examples and modify the YAML files as required for your topology. Details for how to use examples and reasonable modifications are below in the Examples section.
   2. Create your own YAML files if you need a completely custom topology.

3. Populate the Kubernetes manifest YAML files with the required information. You will need to, at a minimum, replace the following:

   1. Names of elements
   2. Environment Variables
   3. Licensing mechanism. Examples here currently use a secret exposed as an environment variable in the meshrr-init container which will populate the license into the config. This may be appropriate for bundle licenses where it is appropriate to use the same license file for many similar devices in a deployment or daemonset. You can create this using:

   kubectl create secret generic crpd-license --from-file=crpd-license=<filepath>
   

   Note that <filepath> must point to a file that contains the singular license line and not an entire license file. 4. (If required) Custom configuration Jinja2 templates loaded into ConfigMaps and mapped as volumes. See Examples.

4. (If required - e.g., for 2regions-hrr where only certain nodes should host certain clusters of RRs) Apply appropriate labels to the nodes:

   kubectl label nodes <node> <label1>=<value> <label2>=<value>

5. Apply your configuration:

   kubectl [-n namespace] apply -f <file1>
   kubectl [-n namespace] apply -f <file2>

Environment Variables

Variable	Required for	Optional for	Description
LICENSE_KEY	meshrr-init		License key to be used for the cRPD container; expected to be a single line.
POD_IP	meshrr-init, meshrr		The pod's IP address. Must be set by Kubernetes manifest in all pod templates for all meshrr containers. This does not need to be set for the cRPD containers. (valueFrom: fieldRef: fieldPath: status.podIP)
UPDATE_SECONDS		meshrr	Frequency in seconds that meshrr container will attempt to update crpd container with changes to peers. (Default: 30)

Containers

• Init Container - meshrr-init:
  • run.sh with arg init
  • Creates configuration from default template or mounted template or derives from existing /config/juniper.conf if pod uses persistent storage.
• Container - crpd:
  • Unmodified cRPD image running Juniper cRPD.
• Container - meshrr:
  • Conducts periodic BGP peer configuration changes on crpd container via Netconf.

BGP Group Types

• mesh
  • Discovers peers and connects to all or a limited number of them.
  • Currently, the only BGP peer discovery mode is dns, which uses a Kubernetes headless service DNS A records to detect peers. New peers are added to config, removed peers are removed from config.
  • Supports a max_peers setting, which limits the number of peers added in this group. This is suitable for connections to a higher tier in a hierarchical route reflector / route server topology.
• subtractive
  • This can be seen as a "wildcard". This is suitable for an environment in which not all peers are strictly defined and uses Junos BGP group allow config to permit connections from a range.
  • The allow config is dynamically generated based on the list of all prefixes in the meshrr configuration with all peers from any mesh groups removed.

Examples

• 2regions-hrr
  • Hierarchicial route reflectors broken into two regions with a single core region unifying them.
  • Reachability via static routes and Kubernetes NodeIP Services referencing additional loopbacks on the Kubernetes nodes.
• load-balanced-route-servers
  • EVPN route servers deployed in a full iBGP mesh with each other serving eBGP peers. Intended to scale DCI for multi-region deployment.
  • Reachability for external devices achieved through use of MetalLB in BGP mode.

Example Commands

Command	Description
kubectl [-n NAMESPACE] get pods -o wide	List pods and the nodes on which they run
kubectl [-n NAMESPACE] exec -it POD -c crpd -- cli	Access the CLI of cRPD
kubectl [-n NAMESPACE] exec POD -c crpd -- cli show bgp summary	See the show bgp summary output of a pod
kubectl [-n NAMESPACE] exec POD -c crpd -- cli show bgp group summary |except \"Allow|orlonger|^Default|^$\"	See the status of the neighbor groups of a pod
kubectl [-n NAMESPACE] logs [-f] POD -c meshrr	View the logs from the meshrr sidecar container. -f will follow the logs.
kubectl [-n NAMESPACE] delete pod POD	Delete POD. Because pods should be created by DaemonSet, StatefulSet, or Deployment, a new pod should be recreated in its place; in this context, this may be considered functionally more similar to a "restart" than to a "delete".