Example Service Event Trigger

Example: Service Event Trigger

In this example, we want to create an Ingress in the namespace eng as soon as at least one Service is created exposing the HTTPS port.

The below EventSource instance will match any Service in namespace eng exposing either port 443 or port 8443.

EventSource Definition

cat > eventsource.yaml <<EOF
---
apiVersion: lib.projectsveltos.io/v1beta1
kind: EventSource
metadata:
  name: https-service
spec:
  collectResources: true
  resourceSelectors:
  - group: ""
    version: "v1"
    kind: "Service"
    namespace: eng
  evaluate: |
    function evaluate()
      hs = {}
      hs.matching = false
      if obj.spec.ports ~= nil then
        for _,p in pairs(obj.spec.ports) do
          if p.port == 443 or p.port == 8443 then
            hs.matching = true
          end
        end
      end
      return hs
    end
EOF

The below EventTrigger instance is referencing the EventSource instance defined above, and it is referencing a ConfigMap containing a template for an Ingress resource.

Note

The oneForEvent field is set to false and instructs Sveltos to create a single Ingress for all Service instances in the managed cluster matching the EventSource.

When oneForEvent is set to false, when instantiating the Ingress template, Resources is an array containing all Services in the managed cluster matching the EventSource. Any field can be accessed.

EventTrigger Definition

cat > eventtrigger.yaml <<EOF
---
apiVersion: lib.projectsveltos.io/v1beta1
kind: EventTrigger
metadata:
  name: ingress-configuration
spec:
  sourceClusterSelector:
    matchLabels:
      env: fv
  eventSourceName: https-service
  oneForEvent: false
  policyRefs:
  - name: ingress
    namespace: default
    kind: ConfigMap
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: ingress
  namespace: default
  annotations:
    projectsveltos.io/template: ok
data:
  ingress.yaml: |
    apiVersion: networking.k8s.io/v1
    kind: Ingress
    metadata:
      name: ingress
      namespace: default
      annotations:
        nginx.ingress.kubernetes.io/rewrite-target: /
    spec:
      ingressClassName: http-ingress
      rules:
        - http:
            paths:
            {{ range $resource := .Resources }}
            - path: /{{ .metadata.name }}
              pathType: Prefix
              backend:
                service:
                  name: {{ .metadata.name }}
                  port:
                    {{ range .spec.ports }}
                    {{ if or (eq .port 443 ) (eq .port 8443 ) }}
                    number: {{ .port }}
                    {{ end }}
                    {{ end }}
            {{ end }}
EOF    

If we have two Service instance in the managed cluster in the namespace eng

$ kubectl get service -n eng
NAME           TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)           AGE
my-service     ClusterIP   10.225.83.46   <none>        80/TCP,443/TCP    15m
my-service-2   ClusterIP   10.225.108.8   <none>        80/TCP,8443/TCP   14m

Sveltos will create below Ingress instance.

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    projectsveltos.io/hash: sha256:bc1e74450d20acedefca38f20cb998b7b24c12ac34e4b501d19b617568926140
  creationTimestamp: "2023-03-16T16:35:11Z"
  generation: 1
  labels:
    projectsveltos.io/reference-kind: ConfigMap
    projectsveltos.io/reference-name: sveltos-l6hldpydjngao4r23evm
    projectsveltos.io/reference-namespace: projectsveltos
  name: ingress
  namespace: default
  ownerReferences:
  - apiVersion: config.projectsveltos.io/v1beta1
    kind: ClusterProfile
    name: sveltos-rgdn6jsy9zivek7e9mtz
    uid: 29f3552b-be4b-447f-bfc0-aedbad5b21db
  resourceVersion: "6186"
  uid: 080a6713-4da1-45a4-b189-2ded216fc688
spec:
  ingressClassName: http-ingress
  rules:
  - http:
      paths:
      - backend:
          service:
            name: my-service
            port:
              number: 443
        path: /my-service
        pathType: Prefix
      - backend:
          service:
            name: my-service-2
            port:
              number: 8443
        path: /my-service-2
        pathType: Prefix
status:
  loadBalancer: {}