exposecontroller

exposecontroller

Automatically expose services creating ingress rules, openshift routes or modifying services to use kubernetes nodePort or loadBalancer service types

Getting started

We're adding support for Helm however until then if you want to get going quick using our defaults:

kubectl create -f http://central.maven.org/maven2/io/fabric8/devops/apps/exposecontroller/2.2.268/exposecontroller-2.2.268-kubernetes.yml

kubectl label svc foo expose=true

If you have gofabric8 then

gofabric8 service foo

else get the external URL from the service annotation and paste in into your browser

kubectl get svc foo -o=yaml

Configuration

We use a Kubernetes ConfigMap and two main config entries

• domain when using either Kubernetes Ingress or OpenShift Routes you will need to set the domain that you've used with your DNS provider (fabric8 uses cloudflare) or nip.io if you want a quick way to get running.
• exposer used to describe which strategy exposecontroller should use to access applications

Automatic

If no config map or data values provided exposecontroller will try and work out what exposer or domain config for the playform.

• exposer - Minishift anf Minikube will default to NodePort, we use Ingress for Kubernetes or Route for OpenShift.
• domain - using nip.io for magic wildcard DNS, exposecontroller will try and find a https://stackpoint.io HAProxy or Nginx Ingress controller. We also default to the single VM IP if using minishift or minikube. Together these create an external hostname we can use to access our applications.

Exposer types

• Ingress - Kubernetes Ingress
• LoadBalancer - Cloud provider external load-balancer
• NodePort - Recomended for local development using minikube / minishift without Ingress or Router running. See also the Kubernetes NodePort documentation.
• Route - OpenShift Route

cat <<EOF | kubectl create -f -
apiVersion: "v1"
data:
  config.yml: |-
    exposer: "Ingress"
    domain: "replace.me.io"
kind: "ConfigMap"
metadata:
  name: "exposecontroller"
EOF

OpenShift

Same as above but using the oc client binary

NOTE

If you're using OpenShift then you'll need to add a couple roles:

oc adm policy add-cluster-role-to-user cluster-admin system:serviceaccount:default:exposecontroller
oc adm policy add-cluster-role-to-group cluster-reader system:serviceaccounts # probably too open for all setups

Label

Now label your service with expose=true in CD Pipelines or with the CLI:

kubectl label svc foo expose=true

exposecontroller will use your exposer type in the configmap above to automatically watch for new services and create ingress / routes / nodeports / loadbalacers for you.

Using the expose URL in other resources

Having an external URL is extremely useful. Here are some other uses of the expose URL in addition to the annotation that gets applied to the Service

ConfigMap

Sometimes web applications need to know their external URL so that they can use that link or host/port when generating documentation or links.

For example the Gogs application needs to know its external URL so that it can show the user how to do a git clone from the command line.

If you wish to enable injection of the expose URL into a ConfigMap then

• create a ConfigMap with the same name as the Service and in the same namespace
• Add the following annotations to this ConfigMap for inserting automatically values into this map when the service gets exposed. The values of these annotations are used as keys in this config map.
  • expose.config.fabric8.io/url-key : Exposed URL
  • expose.config.fabric8.io/host-key : host or host + port when port is not equal 80 (e.g. host:port)
  • expose.config.fabric8.io/apiserver-key : Kubernetes / OpenShift API server host and port (format host:port)
  • expose.config.fabric8.io/apiserver-url-key : Kubernetes / OpenShift API server URL (format https://host:port)
  • expose.config.fabric8.io/apiserver-protocol-key : Kubernetes / OpenShift API server protocol (either http or https)
  • expose.config.fabric8.io/console-url-key : OpenShift Web Console URL
  • expose.config.fabric8.io/oauth-authorize-url-key : OAuth Authorization URL
  • expose.service-key.config.fabric8.io/foo : Exposed URL of the service called foo
  • expose-full.service-key.config.fabric8.io/foo : Exposed URL of the service called foo ensuring that the URL ends with a / character

E.g. when you set an annotation on the config map expose.config.fabric8.io/url-key: service.url then an entry to this config map will be added with the key service.url and the value of the exposed service URL when a service of the same name as this configmap gets exposed.

There is an example of the use of these annotations in the Gogs ConfigMap

OAuthClient

When using OpenShift and OAuthClient you need to ensure your external URL is added to the redirectURIs property in the OAuthClient.

If you create your OAuthClient in the same namespace with the same name as your Service then it will have its expose URL added automatically to the redirectURIs

Building

• install go version 1.7.1 or later
• type the following:
• when using minikube or minishift expose the docker daemon to build the exposecontroller image and run inside kubernetes. e.g eval $(minikube docker-env)

git clone git://github.com/fabric8io/exposecontroller.git $GOPATH/src/github.com/fabric8io/exposecontroller
cd $GOPATH/src/github.com/fabric8io/exposecontroller

make

Running locally

Make sure you've got your kube config file set up properly (remember to oc login if you're using OpenShift).

make && ./bin/exposecontroller

Run on Kubernetes or OpenShift

• build the binary make
• build docker image make docker
• run in kubernetes kubectl create -f examples/config-map.yml -f examples/deployment.yml

Developing

Glide is as the exposecontroller package management

• install glide

Future

On startup it would be good to check if an ingress controller is already running in the cluster, if not create one in an appropriate namespace using a nodeselector that chooses a node with a public ip.