Deploy Varnish as a cache server in Kubernetes

kustomization.yaml file:

---
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization

resources:
- deployment.yaml
- service.yaml

configMapGenerator:
  - name: varnish-config
    files:
      - default.vcl

Varnish deployment.yaml:

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: dev-justynio-ghost-varnish-deployment
  labels:
    app: ghost-varnish
    domain: dev.justyn.io
spec:
  replicas: 1
  selector:
    matchLabels:
      app: ghost-varnish
      domain: dev.justyn.io
  template:
    metadata:
      labels:
        app: ghost-varnish
        domain: dev.justyn.io
    spec:
      containers:
      - name: varnish
        image: varnish:6.4
        imagePullPolicy: Always
        ports:
        - containerPort: 80
        volumeMounts:
        - mountPath: /etc/varnish/default.vcl
          name: varnish-config
          subPath: default.vcl
      volumes:
      - name: varnish-config
        configMap:
          name: varnish-config
          items:
            - key: default.vcl
              path: default.vcl

Varnish service.yaml:

---
kind: Service
apiVersion: v1
metadata:
  name: dev-justynio-ghost-varnish-svc
spec:
  selector:
    app: ghost-varnish
    domain: dev.justyn.io
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80

Example Varnish configuration file, default.vcl, used in the above kustomization.yaml:

vcl 4.0;

backend default {
  .host = "dev-justynio-ghost-svc:80";
}

Not shown: The above examples are copied from a deployment where I have Varnish sitting in front of Ghost. The traffic flows from nginx-ingress to Varnish and then to ghost. My ingress definition points to the Varnish service, but the varnish configuration itself points to the Ghost service.

References

• https://hub.docker.com/_/varnish