Tectonic Ingress

Tectonic AWS and bare-metal clusters include an Ingress Controller to expose the Tectonic Console and Tectonic Identity services. Ingress controllers watch the Kubernetes API for Ingress resources and update their configuration to expose Kubernetes services. When service traffic is routed through Ingress controllers, services of type LoadBalancer, NodePort, and HostPort are not required. Ingress resources can have rules which match hostnames, match paths, and perform TLS termination.

• On Tectonic bare-metal, Ingress controllers are run as a daemonset on host ports across worker nodes by default.
• On Tectonic AWS, Ingress controllers are run as a deployment with node ports behind an AWS ELB by default.

Using Tectonic Ingress

Starting with 1.5.5-tectonic.3, the Tectonic Ingress Controller can be used for user applications as well.

Create an Ingress resource for a service hello, using the kubernetes.io/ingress.class annotation. Without the annotation, the Tectonic Ingress controller will ignore the Ingress resource.

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: hello
  annotations:
    kubernetes.io/ingress.class: "tectonic"
spec:
  rules:
    - host: hello.example.com
      http:
        paths:
          - path: /
            backend:
              serviceName: hello
              servicePort: 80

You can view Ingress resources in the Tectonic Console:

Viewing Ingress Rules in the Tectonic Console

Or by using kubectl:

$ kubectl get ingress
NAME      HOSTS               ADDRESS                   PORTS     AGE
hello     hello.example.com   172.18.0.22,172.18.0.23   80        1h

Test your rules

Next, test that traffic to hello.example.com reaches the cluster's Ingress Controllers.

On Tectonic bare-metal, add a DNS record on your network which resolves hello.example.com to any worker node(s), similar to how the Tectonic DNS entry was setup while going through the installer. In a pinch, you could test this by adding an /etc/hosts entry

workerIP hello.example.com

For Tectonic AWS, add a DNS CNAME record hello.example.com to your Tectonic ELB. It ends in -tec and can be found on your AWS dashboard.

Visit the example application http://hello.example.com. Learn more about Ingress and add TLS termination for HTTPS apps.

Running your own Ingress

Using Tectonic's built-in Ingress Controller works well for everyday HTTP workloads. However, you may run an application that requires more customized logic. For example, complex header manipulation as the routing rules are applied.

Running an ingress controller

There are several different Ingress Controllers that you can run. Nginx and haproxy are the most popular. Familiarize yourself with their documentation for how to deploy them. Typically this is done as a Deployment/DaemonSet and a corresponding Service.

Aside from the normal Ingress Controller options, pay attention to the following:

Class - The flag --ingress-class=my-custom-ingress allows for rules to target this ingress controller. Namespace - The flag --watch-namespace=example will ensure that only a specific namespace is watched for ingress rules. This can prevent others from using your Ingress Controller. Service Account - In your Ingress Controller definition, set the serviceAccountName parameter equal to a Service Account with the correct RBAC policy. Tectonic provides a role ingress-controller for this purpose. Read more about service accounts.

Here is a full example:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: production-ingress
  namespace: production
  labels:
    k8s-app: ingress
spec:
  replicas: 2
  template:
    metadata:
      labels:
        k8s-app: ingress
    spec:
      containers:
        - name: nginx-ingress-lb
          image: gcr.io/google_containers/nginx-ingress-controller:0.9.0-beta.11
          args:
          - /nginx-ingress-controller
          - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
          - --configmap=$(POD_NAMESPACE)/production-ingress-conf
          - --watch-namespace=$(POD_NAMESPACE)
          - --ingress-class=my-custom-ingress
          # use downward API
          env:
            - name: POD_NAME
              valueFrom:
                fieldRef:
                  fieldPath: metadata.name
            - name: POD_NAMESPACE
              valueFrom:
                fieldRef:
                  fieldPath: metadata.namespace
          ports:
            - name: http
              containerPort: 80
            - name: https
              containerPort: 443
            - name: health
              containerPort: 10254
          readinessProbe:
           httpGet:
             path: /healthz
             port: 10254
             scheme: HTTP
          livenessProbe:
           initialDelaySeconds: 10
           timeoutSeconds: 1
           httpGet:
             path: /healthz
             port: 10254
             scheme: HTTP
      dnsPolicy: ClusterFirst
      restartPolicy: Always
      terminationGracePeriodSeconds: 60
      serviceAccountName: production-ingress-serviceaccount

Writing Ingress Rules

To ensure that your rules are satisfied by only your Ingress Controller, specify the Ingress class annotation on your rules:

metadata:
  name: custom-rules
  annotations:
    kubernetes.io/ingress.class: "my-custom-ingress"

After your Ingress Controller is running and your rules have been defined, you should be able to send traffic to your Service and have it routed appropriately.