Node

Node Event-driven I/O server-side JavaScript environment based on V8.

TL;DR

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install bitnami/node

Introduction

This chart bootstraps a Node deployment on a Kubernetes cluster using the Helm package manager.

It clones and deploys a Node.js application from a Git repository. Optionally, you can set up an Ingress resource to access your application and provision an external database using the Kubernetes service catalog and the Open Service Broker for Azure.

Bitnami charts can be used with Kubeapps for deployment and management of Helm Charts in clusters. This Helm chart has been tested on top of Bitnami Kubernetes Production Runtime (BKPR). Deploy BKPR to get automated TLS certificates, logging and monitoring for your applications.

Prerequisites

• Kubernetes 1.4+ with Beta APIs enabled
• PV provisioner support in the underlying infrastructure

Installing the Chart

To install the chart with the release name my-release:

$ helm repo add bitnami https://charts.bitnami.com/bitnami
$ helm install --name my-release bitnami/node

These commands deploy Node.js on the Kubernetes cluster in the default configuration. The configuration section lists the parameters that can be configured during installation. Also includes support for MariaDB chart out of the box.

Due that the Helm Chart clones the application on the /app volume while the container is initializing, a persistent volume is not required.

Tip: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Configuration

The following table lists the configurable parameters of the Node chart and their default values.

The above parameters map to the env variables defined in bitnami/node. For more information please refer to the bitnami/node image documentation.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install --name my-release \
  --set repository=https://github.com/jbianquetti-nami/simple-node-app.git,replicas=2 \
    bitnami/node

The above command clones the remote git repository to the /app/ directory of the container. Additionally it sets the number of replicas to 2.

Alternatively, a YAML file that specifies the values for the above parameters can be provided while installing the chart. For example,

$ helm install --name my-release -f values.yaml bitnami/node

Tip: You can use the default values.yaml

Rolling VS Immutable tags

It is strongly recommended to use immutable tags in a production environment. This ensures your deployment does not change automatically if the same tag is updated with a different image.

Bitnami will release a new chart updating its containers if a new version of the main container, significant changes, or critical vulnerabilities exist.

Persistence

The Bitnami Node image stores the Node application and configurations at the /app path of the container.

Persistent Volume Claims are used to keep the data across deployments. This is known to work in GCE, AWS, and minikube. See the Configuration section to configure the PVC or to disable persistence.

Adjust permissions of persistent volume mountpoint

As the image run as non-root by default, it is necessary to adjust the ownership of the persistent volume so that the container can write data into it.

By default, the chart is configured to use Kubernetes Security Context to automatically change the ownership of the volume. However, this feature does not work in all Kubernetes distributions. As an alternative, this chart supports using an initContainer to change the ownership of the volume before mounting it in the final destination.

You can enable this initContainer by setting volumePermissions.enabled to true.

Set up an Ingress controller

First install the nginx-ingress controller via helm:

$ helm install stable/nginx-ingress

Now deploy the node helm chart:

$ helm install --name my-release bitnami/node --set ingress.enabled=true,ingress.host=example.com,service.type=ClusterIP

Configure TLS termination for your ingress controller

You must manually create a secret containing the certificate and key for your domain. You can do it with this command:

$ kubectl create secret tls my-tls-secret --cert=path/to/file.cert --key=path/to/file.key

Then ensure you deploy the Helm chart with the following ingress configuration:

ingress:
  enabled: false
  path: /
  host: example.com
  annotations:
    kubernetes.io/ingress.class: nginx
  tls:
      hosts:
        - example.com

Connect your application to an already existing database

1. Create a secret containing your database credentials:

   $ kubectl create secret generic my-database-secret --from-literal=host=YOUR_DATABASE_HOST --from-literal=port=YOUR_DATABASE_PORT --from-literal=username=YOUR_DATABASE_USER  --from-literal=password=YOUR_DATABASE_PASSWORD --from-literal=database=YOUR_DATABASE_NAME

   YOUR_DATABASE_HOST, YOUR_DATABASE_PORT, YOUR_DATABASE_USER, YOUR_DATABASE_PASSWORD, and YOUR_DATABASE_NAME are placeholders that must be replaced with correct values.

2. Deploy the node chart specifying the secret name

   $ helm install --name node-app --set mongodb.install=false,externaldb.secretName=my-database-secret bitnami/node

Provision a database using the Open Service Broker for Azure

1. Install Service Catalog in your Kubernetes cluster following this instructions
2. Install the Open Service Broker for Azure in your Kubernetes cluster following this instructions

TIP: you may want to install the osba chart setting the modules.minStability=EXPERIMENTAL to see all the available services.

$ helm install azure/open-service-broker-azure --name osba --namespace osba \
       --set azure.subscriptionId=$AZURE_SUBSCRIPTION_ID \
       --set azure.tenantId=$AZURE_TENANT_ID \
       --set azure.clientId=$AZURE_CLIENT_ID \
       --set azure.clientSecret=$AZURE_CLIENT_SECRET \
       --set modules.minStability=EXPERIMENTAL

3. Create and deploy a ServiceInstance to provision a database server in Azure cloud.

   apiVersion: servicecatalog.k8s.io/v1beta1
   kind: ServiceInstance
   metadata:
   name: azure-mongodb-instance
   labels:
     app: mongodb
   spec:
   clusterServiceClassExternalName: azure-cosmosdb-mongo-account
   clusterServicePlanExternalName: account
   parameters:
     location: YOUR_AZURE_LOCATION
     resourceGroup: mongodb-k8s-service-catalog
     ipFilters:
       allowedIPRanges:
       -  "0.0.0.0/0"

   Please update the YOUR_AZURE_LOCATION placeholder in the above example.

   $ kubectl create -f mongodb-service-instance.yml

4. Deploy the helm chart:

   $ helm install --name node-app --set mongodb.install=false,externaldb.broker.serviceInstanceName=azure-mongodb-instance,externaldb.ssl=true bitnami/node

Once the instance has been provisioned in Azure, a new secret should have been automatically created with the connection parameters for your application.

Deploying the helm chart enabling the Azure external database makes the following assumptions:

• You would want an Azure CosmosDB MongoDB database
• Your application uses DATABASE_HOST, DATABASE_PORT, DATABASE_USER, DATABASE_PASSWORD, and DATABASE_NAME environment variables to connect to the database.

You can read more about the kubernetes service catalog at https://github.com/kubernetes-bitnami/service-catalog

Notable changes

7.0.0

This release includes security contexts, so the containers in the chart are run as non-root. More information in this link.

Upgrading

To 6.0.0

Backwards compatibility is not guaranteed unless you modify the labels used on the chart's deployments. Use the workaround below to upgrade from versions previous to 6.0.0. The following example assumes that the release name is node:

$ kubectl patch deployment node --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'
$ kubectl patch deployment node-mongodb --type=json -p='[{"op": "remove", "path": "/spec/selector/matchLabels/chart"}]'