Pods scheduled to a node receive an IP address from the node’s Pod CIDR range. At this point pods can not communicate with other pods running on different nodes due to missing network routes.
In this lab you will create a route for each worker node that maps the node’s Pod CIDR range to the node’s internal IP address.
There are other ways to implement the Kubernetes networking model.
In this section you will gather the information required to create routes in the kubernetes-the-hard-way VPC network.
Print the internal IP address and Pod CIDR range for each worker instance:
for instance in worker-0 worker-1 worker-2; do
gcloud compute instances describe ${instance} \
--format 'value[separator=" "](networkInterfaces[0].networkIP,metadata.items[0].value)'
done
output
10.240.0.20 10.200.0.0/24
10.240.0.21 10.200.1.0/24
10.240.0.22 10.200.2.0/24
Create network routes for each worker instance:
for i in 0 1 2; do
gcloud compute routes create kubernetes-route-10-200-${i}-0-24 \
--network kubernetes-the-hard-way \
--next-hop-address 10.240.0.2${i} \
--destination-range 10.200.${i}.0/24
done
List the routes in the kubernetes-the-hard-way VPC network:
gcloud compute routes list --filter "network: kubernetes-the-hard-way"
output
NAME NETWORK DEST_RANGE NEXT_HOP PRIORITY
default-route-77bcc6bee33b5535 kubernetes-the-hard-way 10.240.0.0/24 1000
default-route-b11fc914b626974d kubernetes-the-hard-way 0.0.0.0/0 default-internet-gateway 1000
kubernetes-route-10-200-0-0-24 kubernetes-the-hard-way 10.200.0.0/24 10.240.0.20 1000
kubernetes-route-10-200-1-0-24 kubernetes-the-hard-way 10.200.1.0/24 10.240.0.21 1000
kubernetes-route-10-200-2-0-24 kubernetes-the-hard-way 10.200.2.0/24 10.240.0.22 1000