Kubernetes MetalLB External IP not reachable - nginx

Question

I can't access to Network IP assigned by MetalLB load Balancer
I created a Kubernetes cluster in k3s. Its 1 master and 1 workers. Each one has its own Private IP.
Master 192.168.0.13
Worker 192.168.0.13
I Installed k3s with INSTALL_K3S_EXEC=" --no-deploy servicelb --no-deploy traefik"
Now I am trying to deploy a app using MetalLB and nginx ingress
--set configInline.address-pools[0].name=default \
--set configInline.address-pools[0].protocol=layer2 \
--set configInline.address-pools[0].addresses[0]=192.168.0.21-192.168.0.30
helm install nginx-ingress stable/nginx-ingress --namespace kube-system \
--set controller.image.repository=quay.io/kubernetes-ingress-controller/nginx-ingress-controller\
--set controller.image.tag=0.30.0 \
--set controller.image.runAsUser=33 \
--set defaultBackend.enabled=false
I Can see every pod up and running
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
coredns-d798c9dd-lsdnp 1/1 Running 5 37h 10.42.0.25 c271-k3s-ocrh <none> <none>
local-path-provisioner-58fb86bdfd-bcpl7 1/1 Running 5 37h 10.42.0.22 c271-k3s-ocrh <none> <none>
metrics-server-6d684c7b5-v9tmh 1/1 Running 5 37h 10.42.0.24 c271-k3s-ocrh <none> <none>
metallb-speaker-4kbmw 1/1 Running 0 4m7s 192.168.0.14 c271-k3s-agent <none> <none>
metallb-controller-75bf779d4f-nb47l 1/1 Running 0 4m7s 10.42.1.45 c271-k3s-agent <none> <none>
metallb-speaker-776p9 1/1 Running 0 4m7s 192.168.0.13 c271-k3s-ocrh <none> <none>
nginx-ingress-default-backend-5b967cf596-554bq 1/1 Running 0 98s 10.42.1.46 c271-k3s-agent <none> <none>
nginx-ingress-controller-674675d5b6-blndp 1/1 Running 0 98s 10.42.1.47 c271-k3s-agent <none> <none>
App getting IP 192.168.0.21
❯ kubectl get services -n kube-system -l app=nginx-ingress -o wide
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
nginx-ingress-default-backend ClusterIP 10.43.170.195 <none> 80/TCP 112s app=nginx-ingress,component=default-backend,release=nginx-ingress
nginx-ingress-controller LoadBalancer 10.43.220.166 192.168.0.21 80:31735/TCP,443:31566/TCP 111s app=nginx-ingress,component=controller,release=nginx-ingress
I Can access the app from master and worker by curl to nginx controller pod
HTTP/1.1 200 OK
Server: nginx/1.17.8
Date: Sat, 21 Mar 2020 10:43:34 GMT
Content-Type: text/html
Content-Length: 153
Connection: keep-alive
But the IP is not accessible from local 192.168.0.21
Diagnosis : DHCP is on, and 192.168.0.21-192.168.0.30 is absolutely free., When i try to allocate 192.168.0.21 to master or agent by netplan config they get the IP.
Please Guide me, What i am missing.

Answer 1

You need to make sure that the source IP address (external-ip assigned by metallb) is preserved. To achieve this, set the value of the externalTrafficPolicy field of the ingress-controller Service spec to Local. For example
apiVersion: v1
kind: Service
metadata:
name: my-app
labels:
helm.sh/chart: webapp-0.1.0
app.kubernetes.io/name: webapp
app.kubernetes.io/instance: my-app
app.kubernetes.io/version: "1.16.0"
app.kubernetes.io/managed-by: Helm
spec:
type: ClusterIP
ports:
- port: 80
targetPort: http
protocol: TCP
name: http
selector:
app.kubernetes.io/name: webapp
app.kubernetes.io/instance: my-app
externalTrafficPolicy: Local
The default value for externalTrafficPolicy field is 'Cluster'. So change it to Local

Answer 2

In my setup with Cilium and HAProxy ingress controller I'd to change externalTrafficPolicy from Local to Cluster
kubectl --namespace ingress-controller patch svc haproxy-ingress \
-p '{"spec":{"externalTrafficPolicy":"Cluster"}}'

Answer 3

from two years I've been using metalLb in my home-lab, and I didn't get the error (although I got other errors for example ., MetalLB fails to assign an IP address from the pool)
I want to share my current setup with folks who are still struggling on the internet.
helm install --create-namespace metallb metallb/metallb -n metallb-system -f values.yaml
configInline:
address-pools:
- name: default
protocol: layer2
addresses:
- 192.168.0.21/30
# can use series like 192.168.0.21-24 too.
Debugging - try to get logs from all the pod in namespace metallb.
kail -n metallb
K8S installed with calico using https://github.com/geerlingguy/ansible-role-kubernetes
Client Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.1", GitCommit:"3ddd0f45aa91e2f30c70734b175631bec5b5825a", GitTreeState:"clean", BuildDate:"2022-05-24T12:17:11Z", GoVersion:"go1.18.2", Compiler:"gc", Platform:"darwin/amd64"}
Kustomize Version: v4.5.4
Server Version: version.Info{Major:"1", Minor:"24", GitVersion:"v1.24.3", GitCommit:"aef86a93758dc3cb2c658dd9657ab4ad4afc21cb", GitTreeState:"clean", BuildDate:"2022-07-13T14:23:26Z", GoVersion:"go1.18.3", Compiler:"gc", Platform:"linux/amd64"}
Maybe switching externalTrafficPolicy to local/cluster may help however, I didn't try. my setup works out of the box.
Good Luck.