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On Google Container Engine, a [network load balancer](https://cloud.google.com/compute/docs/load-balancing/network/) and [firewall rule](https://cloud.google.com/compute/docs/networking#addingafirewall) to allow traffic are automatically created.
To start the service, run:
```sh
kubectl create -f examples/nodesjs-mongodb/web-service.yaml
```
If you are running on a platform that does not support LoadBalancer (i.e Bare Metal), you need to use a [NodePort](https://kubernetes.io/docs/user-guide/services.md#type-nodeport) with your own load balancer.
You may also need to open appropriate Firewall ports to allow traffic.
### Creating the Node.js Controller
The final step is deploying the Node.js container that will run the application code. This container can easily by replaced by any other web serving frontend, such as Rails, LAMP, Java, Go, etc.
The most important thing to keep in mind is how to access the MongoDB service.
If you were running MongoDB and Node.js on the same server, you would access MongoDB like so:
```javascript
MongoClient.connect('mongodb://localhost:27017/database-name', function(err, db) { console.log(db); });
```
With this Kubernetes setup, that line of code would become:
```javascript
MongoClient.connect('mongodb://mongo:27017/database-name', function(err, db) { console.log(db); });
```
The MongoDB Service previously created tells Kubernetes to configure the cluster so 'mongo' points to the MongoDB instance created earlier.
#### Custom Container
You should have your own container that runs your Node.js code hosted in a container registry.
See [this example](https://medium.com/google-cloud-platform-developer-advocates/running-a-mean-stack-on-google-cloud-platform-with-kubernetes-149ca81c2b5d#8edc) to see how to make your own Node.js container.
Once you have created your container, create the web controller.
```yaml
apiVersion: v1
kind: ReplicationController
metadata:
labels:
name: web
name: web-controller
spec:
replicas: 2
selector:
name: web
template:
metadata:
labels:
name: web
spec:
containers:
- image: <YOUR-CONTAINER>
name: web
ports:
- containerPort: 3000
name: http-server
```
[Download file](web-controller.yaml)
Replace <YOUR-CONTAINER> with the url of your container.
This Controller will create two replicas of the Node.js container, and each Node.js container will have the tag "web" and expose port 3000. The Service LoadBalancer will forward port 80 traffic to port 3000 automatically, along with load balancing traffic between the two instances.
To start the Controller, run:
```sh
kubectl create -f examples/nodesjs-mongodb/web-controller.yaml
```
#### Demo Container
If you DON'T want to create a custom container, you can use the following YAML file:
Note: You cannot run both Controllers at the same time, as they both try to control the same Pods.
```yaml
apiVersion: v1
kind: ReplicationController
metadata:
labels:
name: web
name: web-controller
spec:
replicas: 2
selector:
name: web
template:
metadata:
labels:
name: web
spec:
containers: