script.txt

# Create deployment and service
kubectl apply -f deployment.yaml -f service.yaml
kubectl get all

kubectl describe ep echo

# Create pod and access service
kubectl run -it test  --image appropriate/curl ash
while true ; do curl <service ip> ; sleep 1 ; done

# Readiness probe
## Second window
kubectl exec -it <curl pod> sh
curl <podip>:5000/ready
curl <podip>:5000/toggleReady
curl <podip>:5000/ready

exit
kubectl get pods
# [Ready : 0/1]
kubectl describe ep echo
kubectl describe pod <unready pod>
# [NotReadyAddresses]

## Set pod as ready

sudo iptables -t nat -L KUBE-SERVICES
sudo iptables -t nat -L KUBE-SVC-
sudo iptables -t nat -L KUBE-SEP-

# hairpin
# pick pod from host
kubectl exec echodeploy-xxxx -it sh
hostname -i
while true ; do wget -q -O - 10.200.20.164 ; sleep 1 ; done

# affinity
kubectl apply -f service-persistent.yaml
curl 10.200.20.164 ; curl 10.200.20.164 ; curl 10.200.20.164

sudo iptables -t nat -L KUBE-SVC-
cat /proc/net/xt_recent/KUBE-SEP-

### ipvs
kubectx lbipvs.eu1.staging.dog
kubectl apply -f deployment.yaml -f service.yaml
kubectl get all

kubectl run -it test  --image appropriate/curl ash
while true ; do curl <service ip> ; sleep 1 ; done

ssh <node>
sudo ipvsadm --list --numeric --tcp-service 10.200.200.68:80
sudo ip -d addr show dev kube-ipvs0

## Persistency
k apply -f service-persistent.yaml
sudo ipvsadm --list --numeric --tcp-service 10.200.200.68:80

## Hairpin
sudo iptables -t nat -L KUBE-POSTROUTING
sudo ipset -L KUBE-LOOP-BACK

## DNS
k exec -it test-7b944db754-g885v sh
cat /etc/resolv.conf
curl echo

## External access
ssh laurent.bernaille@datadog-kube-client
curl <podip>:5000
curl <serviceip>

sudo iptables -t nat -N KUBE-MARK-DROP
sudo iptables -t nat -A KUBE-MARK-DROP -j MARK --set-xmark 0x8000/0x8000

sudo ./kube-proxy --kubeconfig=kubeconfig
while true ; do curl 10.200.164.177 ; sleep 1 ; done

cat /etc/dnsmasq.conf
while true ; do curl echo.default.svc.cluster.local ; sleep 1 ; done