.. _ingress:

Ingress
-------

By now you should have created a :ref:`deployment` that creates 1 or more pods and grouped by a :ref:`service`
to a single IP address.

An `ingress <https://kubernetes.io/docs/concepts/services-networking/ingress/>`_ exposes the **service** to the outside world.  In addition, it provides routing
by DNS names.   You may have many pods that accept calls on HTTPS port 443.  An ingress checks
the URL that was used to get to the cluster.  The ingress uses the URL to route the request to
the appropriate server.

Typically, an AWS load balancer is pointing to a target group that contains all worker nodes.  A DNS
entry is created that would route traffic to our domain, for example: ** *.dev.sandbox.simoncomputing.com**.

All traffic would be routed to the worker nodes, where an **ingress controller** will determine which
service to route traffic to based on the complete URL address.

Here is an example YAML file describing an ingress::

    apiVersion: extensions/v1beta1
    kind: Ingress
    metadata:
      name: tomcat-ing-dev
    spec:
      rules:
        - host: tomcat.dev.sandbox.simoncomputing.com
          http:
            paths:
              - path: /
                backend:
                  serviceName: tomcat-svc-dev
                  servicePort: 8080
      tls:
      - hosts:
        - dev.sandbox.simoncomputing.com

Here is an example of creating a deployment, service and ingress:

.. code-block:: python

    from k9.helper import (
        set_default_namespace,
        create_namespace,
        create_secret,

    )

    # create namespace
    set_default_namespace("ingress-unit-test")
    create_namespace()

    # create secret
    secret_name = "tomcat-dev"
    secrets = {
        'url': 'https://some/url',
        'password': 'My1SecretPassword',
        'username': 'postgres'
    }
    create_secret(secret_name, secrets)

    # create deployment
    body = read_yaml('tomcat-deploy-dev.yml')
    create_deployment(body)

    # create service
    body = read_yaml('tomcat-svc-dev.yml')
    create_service(body)

    # create ingress
    body = read_yaml('../test/tomcat-ing-dev.yml')
    create_ingress(body)


.. autofunction:: k9.exts.list_ingress
.. autofunction:: k9.exts.ingress_exists
.. autofunction:: k9.exts.get_ingress
.. autofunction:: k9.exts.create_ingress
.. autofunction:: k9.exts.delete_ingress