If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

There are a few different ways to route external requests to a pod / service.

• Using an OpenShift route (this is the most common)
• Using an ingress route
• Using a load balancer service
• Assign an external IP address to a service

An OpenShift route or an Ingress route will provide a URL such as http://my-route-my-project.apps.openshift.example.com which is used to route a request onto a service, which is then routed onto a pod, and then to the container in the pod, and finally to the application running in the container.

Like this.

The oc expose service command can be used to create an insecured route, whereas the oc create route command is used to create a secured route.

The oc get services command can be used to list the services that have been created in the currently selected. Let's say you want to create an OpenShift route that will be used to route requests to my-service.

~]# oc get services
NAME             TYPE           CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
my-service       ClusterIP      172.30.164.121   <none>        8080/TCP       114d

The oc expose service command can be used to create a route that will be used to route requests onto a service. Often, the following options are used.

• --name - to give your route a certain name
• --port - The port that the service is listening on
• --label - I'm not sure why, but I have to use this to get the route exposed on the default router
• --hostname - By default, hostname will be <route name>-<project/namespace>-<ingress domain name>:<port><optional endpoint> (e.g. http://my-route-my-project.apps.openshift.example.com). The --hostname option can be used to specify the hostname.

~]$ oc expose service my-service --name my-route --port 8080 --labels route-type=default
route.route.openshift.io/my-route exposed

The oc get routes command can then be used the list the routes. In this example, the route URL is http://my-route-my-project.apps.openshift.example.com. The syntax of the URL is <route name>-<project/namespace>-<ingress domain name>:<port><optional endpoint>.

~]# oc get routes
NAME          HOST/PORT                                       PATH   SERVICES    PORT     TERMINATION WILDCARD
my-route      my-route-my-project.apps.openshift.example.com         my-service  8080-tcp             None

The oc describe route command can be used to display more details about the route. Notice that the route has been exposed on router default.

~]$ oc describe route my-route
Name:                   my-route
Namespace:              my-project
Created:                17 minutes ago
Labels:                 name=my-route
Annotations:            openshift.io/host.generated=true
Requested Host:         my-route-my-project.apps.openshift.example.com
                           exposed on router default (host router-default.apps.openshift.example.com) 17 minutes ago
Path:                   /example
TLS Termination:        <none>
Insecure Policy:        <none>
Endpoint Port:          8080

Service:        my-service
Weight:         100 (100%)
Endpoints:      10.217.0.68:8080

The default router pod should be in the openshift-ingress project/namespace.

~]$ oc get pod --namespace openshift-ingress
NAME                             READY   STATUS    RESTARTS      AGE
router-default-f6d44996c-sljgl   1/1     Running   2 (58m ago)   56d

The router pods run an haproxy (high availability proxy) load balancer, which can be seen with the oc exec command.

~]$ oc exec pod/router-default-76c5c89559-dclkw --namespace openshift-ingress -- cat /var/lib/haproxy/conf/haproxy.config | grep my-route
  server pod:my-pod:my-service:8080-tcp:10.129.7.69:8080 10.129.7.69:8080 cookie 15b9071e86b87a2b4b6f976291de96cf weight 256 check inter 5000ms

If the application in the pod is a web based application, you should now be able to interact with the application using the route URL.

Or using curl.

~]# curl my-route-my-project.apps.openshift.example.com
Hello OpenShift!