How can I expose my postgresSQL pods with LoadBalancer service? - postgresql

Question

I setup 1 master node and 2 worker nodes on bare matel server. I deploy my postgressSQL with 3 replica sets. This is my deployment file.
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres
spec:
selector:
matchLabels:
app: postgres
replicas: 3
template:
metadata:
labels:
app: postgres
spec:
containers:
- name: postgres
image: postgres:latest
imagePullPolicy: "IfNotPresent"
envFrom:
- configMapRef:
name: postgres-config
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgredb
volumes:
- name: postgredb
persistentVolumeClaim:
claimName: postgres-pv-claim
---
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: standard
capacity:
storage: 15Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: standard
accessModes:
- ReadWriteMany
resources:
requests:
storage: 15Gi
---
apiVersion: v1
kind: ConfigMap
metadata:
name: postgres-config
labels:
app: postgres
data:
POSTGRES_DB: postgresdb
POSTGRES_USER: postgres
POSTGRES_PASSWORD: root
---
I also follow the MetalLB https://metallb.universe.tf/installation/ and set up layer2 load balancer. which is running fine and I can even expose nginx pod with this service.
As you can see here.
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 4h28m
nginx LoadBalancer 10.107.29.158 153.10.19.35 80:30703/TCP 162m
These are my running pods
NAME READY STATUS RESTARTS AGE
nginx-76d6c9b8c-lrljz 1/1 Running 0 3h29m
postgres-7dff8d6d74-8mlnt 1/1 Running 0 136m
postgres-7dff8d6d74-9zxsk 1/1 Running 0 136m
postgres-7dff8d6d74-xzkkx 1/1 Running 0 136m
What Issue Do I face?
When I try to expose the postgresSQL pods with load balancer I am not able to connect. Server is not reachable.
I try to expose as follow
kubectl expose deploy postgres --port 30432 --type LoadBalancer
I also try to create a yaml file for this service and still not successful.
kind: Service
apiVersion: v1
metadata:
name: postgres-svc
labels:
app: postgres
spec:
type: LoadBalancer
ports:
- port: 5432
targetPort: 30432
type: LoadBalancer
selector:
metallb-service: postgres
What Do I expect?
I want to expose my Pods to external network with this load balancer service so all the new data should be updated in all 3 replica set. Can you please help me to fix my service.yaml file?
I will be very thanks full

Answer 1

You don't specify a port in your postres container.
With kubectl expose you should specify a targetPort:
kubectl expose deploy postgres --port 30432 --target-port 5432 --type LoadBalancer
In your YAML you have to switch ports:
kind: Service
apiVersion: v1
metadata:
name: postgres-svc
labels:
app: postgres
spec:
type: LoadBalancer
ports:
- port: 30432
targetPort: 5432
type: LoadBalancer
selector:
app: postgres
Here also the selector was wrong. It has to match labels on the pod.