kubernetestraefikk3d

Traefik ingress route not working with Prefix or Exact path match on K3D


I'm using K3D to test a local cluster with a simple deployment. I'm following https://github.com/jpetazzo/container.training/tree/main/dockercoins which has 4 deployments one of them being a express app which serves some JS and html (https://github.com/jpetazzo/container.training/blob/main/dockercoins/webui/webui.js)

K3D cluster is created as such:

k3d cluster create k8cluster -p 8081:80@loadbalancer 

So localhost:8081 access all my ingress routes. Ingress controller is in the kube-system namespace and my deployment, service is in the default namespace. I don't believe this is an issue since ingress controller manages rules for all namespaces.

Below is the deployment for the webui:

apiVersion: apps/v1
kind: Deployment
metadata:
  annotations:
    deployment.kubernetes.io/revision: "1"
  creationTimestamp: "2025-02-23T03:20:59Z"
  generation: 1
  labels:
    app: webui
  name: webui
  namespace: default
  resourceVersion: "29220"
  uid: 0c8f8ba6-70c9-4a27-ba72-98b1607340b4
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      app: webui
  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: webui
    spec:
      containers:
      - image: dockercoins/webui:v0.1
        imagePullPolicy: IfNotPresent
        name: webui
        resources: {}
        terminationMessagePath: /dev/termination-log
        terminationMessagePolicy: File
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      schedulerName: default-scheduler
      securityContext: {}
      terminationGracePeriodSeconds: 30
status:
  availableReplicas: 1
  conditions:
  - lastTransitionTime: "2025-02-23T03:20:59Z"
    lastUpdateTime: "2025-02-23T03:21:14Z"
    message: ReplicaSet "webui-6d54d8646b" has successfully progressed.
    reason: NewReplicaSetAvailable
    status: "True"
    type: Progressing
  - lastTransitionTime: "2025-02-23T18:43:56Z"
    lastUpdateTime: "2025-02-23T18:43:56Z"
    message: Deployment has minimum availability.
    reason: MinimumReplicasAvailable
    status: "True"
    type: Available
  observedGeneration: 1
  readyReplicas: 1
  replicas: 1
  updatedReplicas: 1

I have a simple service exposing the deployment as such:

apiVersion: v1
kind: Service
metadata:
  name: webui
  labels:
    app: webui
spec:
  selector:
    app: webui
  ports:
    - port: 80
      targetPort: 80

Exposing the pod through a nodeport works:

apiVersion: v1
kind: Service
metadata:
  labels:
    app: webui
  name: webuinodeport
spec:
  ports:
    - name: 80-80
      nodePort: 30080
      port: 8080
      protocol: TCP
      targetPort: 80
  selector:
    app: webui
  type: NodePort

But trying to create an ingress rule to access this deployment via its service is not working:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: blue
  #annotations:
  #  ingress.kubernetes.io/ssl-redirect: "false"
spec:
  ingressClassName: traefik #nginx
  rules:
    - host: localhost
      http:
        paths:
          - path: /webui
            pathType: Prefix
            backend:
              service:
                name: webui
                port:
                  number: 80

Below are things I confirmed are working:

  1. Pod has no errors and is working correctly
  2. Able to use nodeport to access the pod application
  3. Able to curl the pod IP within the cluster from another pod
  4. Able to curl the service IP within the cluster from another pod
  5. Able to curl the service IP from the traefik controller pod
  6. Deployed a different application (e.g. deployed https://github.com/jpetazzo/color/blob/main/webcolor.go) and it works through ingress route
  7. kubectl logs -n kube-system deploy/traefik --since 1h (shows no errors for the mentioned webui service)

#3,#4,#5 all return the correct output and show index.html. But when I try to access the ingress route all I get is: Cannot GET /webui

What am I missing? Service is valid and points to the correct pod, everything works within the cluster but I can't access it through ingress.


Solution

  • This was not an issue with my ingress rules or any K8 configuration. It was with how the path was defined in ingress alongside how the express app serves requests. Express app was trying to serve static files on the root "/" path instead of the path I defined in ingress /webui.

    Had to adjust static file middleware in express to serve on /webui path and adjusted necessary routes in express and I am able to access things properly.