Reading this article will guide us on how to setup basic steps to expose a Kubernetes service. Example: Accessing an Nginx web server from a Multipass Ubuntu VMs using Kubernetes deployment and service.
Things we need:
Deployment
Below is where we deploy a simply nginx web server with 1 replica that runs on port 8080
cat << EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
labels:
app: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.15.4
ports:
- containerPort: 80
EOF
Install MetalLB
The the commands below to install MetalLB. This is required for us to expose our service (access the nginx web server on our machine / not just inside the VMs (using Multipass))
Source: https://makeoptim.com/en/service-mesh/kubeadm-kubernetes-istio-setup#metallb
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.9.6/manifests/namespace.yaml
kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.9.6/manifests/metallb.yaml
# On first install only
kubectl create secret generic -n metallb-system memberlist --from-literal=secretkey="$(openssl rand -base64 128)"
Get the IP addresses of your worker nodes.
kubectl get nodes -o wideBelow we got the node1 and node two IP’s (doesn’t matter if they are internal)
Now we need to set an IP range for each node. Node1 is 172.29.94.50-172.29.94.254 and Node2 is 172.29.91.50-172.29.91.254
Which means that our service can generate an IP between 172.29.94.50-172.29.94.254 and is 172.29.91.50-172.29.91.254
kubectl apply -f - <<EOF
apiVersion: v1
kind: ConfigMap
metadata:
namespace: metallb-system
name: config
data:
config: |
address-pools:
- name: default
protocol: layer2
addresses:
- 172.29.94.50-172.29.94.254
- 172.29.91.50-172.29.91.254
EOF
You can also edit the MetalLB config by running:
kubectl edit configmap -n metallb-systemExpose the service!
The code below shows that we selected the deployment nginx , we set the type to LoadBalancer and we name the service my-service
kubectl expose deployment nginx --type=LoadBalancer --name=my-service
Check the demo
Remember we are using Multipass to create our VMs, right? The goal here is to access the service inside and outside our Multipass servers.
Inside multipass
[email protected]:~# curl 172.29.94.50 -n 10
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>Outside multipass (Windows command prompt)
Google Chrome from my Windows 10 Machine
