exposecontroller

README

exposecontroller

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

Getting started

Ingress name

The ingress URL uses the service name that contains the expose annotation, if you want this to be a different name then annotate the service:

kubectl annotate svc foo fabric8.io/ingress.name=bar

Multiple backend services

An ingress rule can have multiple service backends, traffic is managed using a path see https://kubernetes.io/docs/concepts/services-networking/ingress/#the-ingress-resource

To add a path to the ingress rule for your service add an annotation:

kubectl annotate svc foo fabric8.io/ingress.path=/api/

Multiple service ports

A service can have multiple ports defined (e.g. 8020 and 8021). To select which port to expose add an annotation:

kubectl annotate svc foo fabric8.io/exposePort=8020

It not annotation is defined, it will pick the first port available in the list.

Daemon mode

To run a one shot exposecontroller pass the --daemon flag

Cleanup

To remove any ingress rules created by exposecontroller use the --cleanup flag

Configuration

We use a Kubernetes ConfigMap and mutltiple config entries. Full list here

• 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
• tls-acme (boolean) used to enable automatic TLS when used in conjunction with kube-lego. Only works with version v2.3.31 onwards.

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 // now deprecated

or

kubectl annotate svc foo fabric8.io/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

Custom annotations

You can add the hostname as a custom annotation on the service, by using the fabric8.io/exposeHostNameAs annotation:

metadata:
  annotations:
    fabric8.io/exposeHostNameAs: osiris.deislabs.io/ingressHostname

will be converted to:

metadata:
  annotations:
    fabric8.io/exposeUrl: https://example.com
    osiris.deislabs.io/ingressHostname: example.com
    fabric8.io/exposeHostNameAs: osiris.deislabs.io/ingressHostname

This is useful if you are working with tools which require access to the exposed hostname at the service level, using a specific annotation, such as Osiris.

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/path-key : Key for this ConfigMap which is used to store the path (useful for injecting as a context path into an app). Defaults to /
  • expose.config.fabric8.io/clusterip-key : Cluster IP for the service for this ConfigMap
  • expose.config.fabric8.io/clusterip-port-key : Cluster IP + port for the service for this ConfigMap
  • expose.config.fabric8.io/clusterip-port-key-if-empty-key : Cluster IP + port for the service for this ConfigMap if the value is empty
  • 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/url-protocol : The default protocol used by Kubernetes Ingress or OpenShift Routes when exposing URLs
  • 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
  • expose-no-path.service-key.config.fabric8.io//foo : Exposed URL of the service called foo with any Service path removed (so just the protocol and host)
  • expose-no-protocol.service-key.config.fabric8.io/foo : Exposed URL of the service called foo with the http protocol removed
  • expose-full-no-protocol.service-key.config.fabric8.io/foo : Exposed URL of the service called foo ensuring that the URL ends with a / character and the http protocol removed
  • "jenkins-x.io/skip.tls" : if tls is enabled and the namespace level this annotation will override it for given service

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

Injecting into ConfigMap entries

Sometimes you have a ConfigMap which contains an entry that is a configuration file that needs to include an expression from the exposed URL.

To do that you can add a blob of YAML in an annotation:

metadata:
  annotations:
    expose.config.fabric8.io/config-yaml: |-
      - key: app.ini
        prefix: "DOMAIN = "
        expression: host
      - key: app.ini
        prefix: "ROOT_URL = "
        expression: url

Available expressions

• host for the host:port of the endpoint
• url for the full URL
• apiserver for the api server host/port
• apiserverURL for the full api server URL

Rolling updates of Deployments

You may want your pods to be restarted if exposecontroller injects a new value into a ConfigMap. if so add the configmap.fabric8.io/update-on-change annotation on your ConfigMap with the value being the name or list of names (separated by ,) of the names of the deployments to perform a rolling upgrade on whenever the ConfigMap changes.

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/jenkins-x/exposecontroller.git $GOPATH/src/github.com/jenkins-x/exposecontroller
cd $GOPATH/src/github.com/jenkins-x/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

Rapid development on Minikube / Minishift

If you run fabric8 in minikube or minishift then you can get rapid feedback of your code via the following:

on openshift:

• oc edit dc exposecontroller on kubernetes:

• kubectl edit deploy exposecontroller

• replace the fabric8/exposecontroller:xxxx image with fabric8/exposecontroller:dev and save

Now when developing you can:

• use the kube-redeploy make target whenever you want to create a new docker image and redeploy

make kube-redeploy

if the docker build fails you may need to type this first to point your local shell at the docker daemon inside minishift/minikube:

eval $(minishift docker-env)
or
eval $(minikube docker-env)

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.