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Simplified services for application exposition

Context​

Kubernetes runs its pods internally. By default, a pod is not exposed outside the cluster. To publish an application to internet or to internal network, you should deal with DNS, TLS certificate and proxy configurations.

K8SaaS provides an all-in-one application publication service that help a developer to expose his application.

Features:

  • scalable proxy
  • DNS domain in kaas.thalesdigital.io
  • Corresponding valid TLS certificate

Alt text

Use case​

  • Publish an application to internet securely
  • Publish an application to the peered network only
  • SSL passthrough

What to do ?​

We assume you have a service called aks-helloworld-one exposed on TCP:80.

To expose its application, you have to create an ingress object.

Option 1 - using kubectl apply:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: <your_app>-ingress # ex: helloworld-ingress
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-staging # ex: see Usage
spec:
  ingressClassName: nginx # ex: see Usage
  tls:
  - hosts:
    - <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  hello-world.dev.project.kaas.thalesdigital.io
    secretName: <your_app>-<your_cluster>-tls # ex: helloworld-dev-tls, in most case this secrete should be unique.
  rules:
  - host: <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  hello-world.dev.project.kaas.thalesdigital.io
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: aks-helloworld-one
            port:
              number: 80

Option 2 - using helm chart:

ingress:
  enabled: true
  ingressClassName: nginx # ex: see Usage
  annotations:
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    cert-manager.io/cluster-issuer: letsencrypt-staging # ex: see Usage
  hosts:
    - host: <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  hello-world.dev.project.kaas.thalesdigital.io
      paths: ["/"]

  tls:
    - secretName: <your_app>-<your_cluster>-tls # ex: helloworld-dev-tls, in most case this secrete should be unique.
      hosts:
        - <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  hello-world.dev.project.kaas.thalesdigital.io

Explanations:

  • metadata.name:
  • spec.ingressClassName:
    • to use the ingressClass respective to your ingress controller, if your controller is :
      • internal (thales provided ip range): nginx-internal
      • external (public, internet facing): nginx
      • namespaced (deployed in a namespace, shared offer): nginx-<your_namespace_name>
  • metadata.annotation.cert-manager.io/cluster-issuer:
    • for testing : letsencrypt-staging
    • for prod : letsencrypt-prod
  • spec:
    • according to your application endpoint and service configuration

Once deployed, you should be able to list your application with:

$ kubectl get ingress -n NAMESPACE

Note: The TLS certificate generation should take 2 minutes. After 5min, if the configuration is not ready, you should have a look to the kubernetes events with:

$ kubectl get events -n NAMESPACE

Note: Send those logs to the support if needed

HOWTO​

Use a valid certificate​

When using letsencrypt-staging, if you try to connect with a browser to your ingress url, you'll see a "Untrusted/Wrong Certificate". It's a normal behavior. letsencrypt-staging provides a fake certificate in order to test the certificate provisioning before going to letsencrypt-prod.

To use a valid certificate, you should update the following line of your ingress:

cert-manager.io/cluster-issuer: letsencrypt-staging

by

cert-manager.io/cluster-issuer: letsencrypt-prod

Then, apply the change to the cluster.

Note: We highly recommend testing against letsencrypt staging environment before using our production environment. This will allow you to get things right before issuing trusted certificates and reduce the chance of your running up against rate limits.

letsencrypt-staging

Bring your own certficate​

In order to use your own certificate, you have to :

  • Disable the letsenscrypt provider for your ingress
  • Provide the certificate as a secret and indicate to nginx to use it

Disable letsencrypt provider​

Remove all cert-manager.io/* annotations

Import your own certificate into the ingress​

To allow Kubernetes to use the TLS certificate and private key for the ingress controller, you create and use a Secret. The secret is defined once, and uses the certificate and private key file. You then reference this secret when you define ingress routes.

The following example creates a Secret named your-ingress-tls in dev namespace:

kubectl create secret tls your-ingress-tls \
    --namespace dev \
    --key ingress-tls.key \
    --cert ingress-tls.crt

Then indicate the ingress route to use this secret as a tls certificate (based on previous example):

spec:
  tls:
  - hosts:
    - <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  hello-world.dev.project.kaas.thalesdigital.io
    secretName: your-ingress-tls

Configure SSL-Passthrough​

First, the nginx ingress controller need to be updated by the k8saas level 2 team. Please ask the support to enable this feature listing:

  • your customer name
  • your cluster name

Once done, you should be able to use the parameters:

  annotations:
    nginx.ingress.kubernetes.io/backend-protocol: "HTTPS"
    nginx.ingress.kubernetes.io/ssl-redirect: "true"
    nginx.ingress.kubernetes.io/ssl-passthrough: "true"
  spec:
    ingressClassName: nginx

Configure permanent redirection​

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: <your_app>-ingress # ex: helloworld-ingress
  annotations:
    nginx.ingress.kubernetes.io/permanent-redirect: newurl  # ex: newurl.kaas.thalesdigital.io
    cert-manager.io/cluster-issuer: letsencrypt-prod # ex: see Usage
spec:
  ingressClassName: nginx # ex: see Usage
  tls:
  - hosts:
    - <your_app>.<your_cluster>.kaas.thalesdigital.io # ex: oldurl.kaas.thalesdigital.io
    secretName: <your_app>-<your_cluster>-tls # ex: helloworld-dev-tls, in most case this secrete should be unique.
  rules:
  - host: <your_app>.<your_cluster>.kaas.thalesdigital.io # ex:  oldurl.kaas.thalesdigital.io
    http:
      paths:
      - path: /

Configure a whitelist​

Note: to perform a whitelisting properly, we strongly recommend using a firewall. Before setuping this feature, please have a look at Pre-Configured firewall section.

To enable the whitelisting feature, you just have to update your current ingress configuration using:

metadata:
  annotations:
    nginx.ingress.kubernetes.io/whitelist-source-range: 49.36.X.X/32
    [...]