From df185c88a579fd68b118617ea5f7988d912cc3ad Mon Sep 17 00:00:00 2001
From: Jerome Petazzoni <jerome.petazzoni@gmail.com>
Date: Sat, 13 Apr 2019 04:30:22 -0500
Subject: [PATCH] Add shell snippet generating route commands

---
 slides/k8s/cni.md | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/slides/k8s/cni.md b/slides/k8s/cni.md
index 16ddfeba..319e39d5 100644
--- a/slides/k8s/cni.md
+++ b/slides/k8s/cni.md
@@ -499,6 +499,32 @@ What does that mean?
 
 ---
 
+class: extra-details
+
+## Other ways to distribute routing tables
+
+- We don't need kube-router and BGP to distribute routes
+
+- The list of nodes (and associated `podCIDR` subnets) is available through the API
+
+- This shell snippet generates the commands to add all required routes on a node:
+
+```bash
+NODES=$(kubectl get nodes -o name | cut -d/ -f2)
+for DESTNODE in $NODES; do
+  if [ "$DESTNODE" != "$HOSTNAME" ]; then
+    echo $(kubectl get node $DESTNODE -o go-template="
+      route add -net {{.spec.podCIDR}} gw {{(index .status.addresses 0).address}}")
+  fi
+done
+```
+
+- This could be useful for embedded platforms with very limited resources
+
+  (or lab environments for learning purposes)
+
+---
+
 # Interconnecting clusters
 
 - We assigned different Cluster CIDRs to each cluster