After you've installed KEDA and the HTTP Add On (this project, we'll call it the "add on" for short), this document will show you how to get started with an example app.
If you haven't installed KEDA and the HTTP Add On (this project), please do so first. Follow instructions install.md to complete your installation. Before you continue, make sure that you have your NAMESPACE
environment variable set to the same value as it was when you installed.
You'll need to install a Deployment
and Service
first. You'll tell the add on to begin scaling it up and down after this step. Use the below Helm command to create the resources you need.
helm install xkcd ./examples/xkcd -n ${NAMESPACE}
You'll need to clone the repository to get access to this chart. If you have your own Deployment
and Service
installed, you can go right to creating an HTTPScaledObject
in the next section.
To remove the app, run
helm delete xkcd -n ${NAMESPACE}
You interact with the operator via a CRD called HTTPScaledObject
. This CRD object points the To get an example app up and running, read the notes below and then run the subsequent command from the root of this repository.
kubectl create -f -n $NAMESPACE examples/v0.0.2/httpscaledobject.yaml
If you'd like to learn more about this object, please see the
HTTPScaledObject
reference.
You've now installed a web application and activated autoscaling by creating an HTTPScaledObject
for it. For autoscaling to work properly, HTTP traffic needs to route through the Service
that the add on has set up. You can use kubectl port-forward
to quickly test things out:
k port-forward svc/xkcd-interceptor-proxy -n ${NAMESPACE} 8080:80
As said above, you need to route your HTTP traffic to the Service
that the add on has created. If you have existing systems - like an ingress controller - you'll need to anticipate the name of these created Service
s. Each one will be named consistently like so, in the same namespace as the HTTPScaledObject
and your application (i.e. $NAMESPACE
):
<deployment name>-interceptor-proxy
The service will always be a
ClusterIP
type and will be created in the same namespace as theHTTPScaledObject
you created.
Installing and Using the ingress-nginx Ingress Controller
As mentioned above, the Service
that the add-on creates will be inaccessible over the network from outside of your Kubernetes cluster.
While you can access it via the kubectl port-forward
command above, we recommend against using that in a production setting. Instead, we recommend that you use an ingress controller to route to the interceptor service. This section describes how to set up and use the NGINX Ingress controller.
First, install the controller using the commands below. These commands use Helm v3. For other installation methods, see the installation page.
helm repo add ingress-nginx https://kubernetes.github.io/ingress-nginx
helm repo update
helm install ingress-nginx ingress-nginx/ingress-nginx -n ${NAMESPACE}
An Ingress
resource was already created as part of the xkcd chart, so the installed NGINX ingress controller will initialize, detect the Ingress
, and begin routing to the xkcd interceptor Service
.
When you're ready, please run kubectl get svc -n ${NAMESPACE}
, find the ingress-nginx-controller
service, and copy and paste its EXTERNAL-IP
. This is the IP address that your application will be running at on the public internet.
Note: you should go further and set your DNS records appropriately and set up a TLS certificate for this IP address. Instructions to do that are out of scope of this document, though.