NodeJS

NodeJS The MEAN stack is MongoDB, Express.js, Angular, and Node.js. Because all components of the MEAN stack support programs written in JavaScript, MEAN applications can be written in one language for both server-side and client-side execution environments.

TL;DR;

  1. $ helm install incubator/mean

Introduction

This chart bootstraps a NodeJS and a MongoDB deployment on a Kubernetes cluster using the Helm package manager.

It clones and deploys a Node.js application from a git repository. Defaults to a demo MEAN application: https://github.com/scotch-io/node-todo.git

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:

  1. $ helm install --name my-release incubator/mean

The command deploys 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 MongoDB 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:

  1. $ helm delete my-release

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

Configuration

The following tables lists the configurable parameters of the NodeJS chart and their default values.

Parameter Description Default
image NodeJS image bitnami/node:{VERSION}
imagePullPolicy Image pull policy IfNotPresent
repository Repo of the application https://github.com/scotch-io/node-todo.git
revision Revision to checkout master
config Contents of the config file for app See repo file config/database.js
configfile Filename of config file for app database.js
mongodb.mongodbRootPassword MongoDB admin password nil
mongodb.mongodbUsername MongoDB username nil
mongodb.mongodbPassword MongoDB username password nil
mongodb.mongodbDatabase MongoDB database name nil
mongodb.persistence.enabled MongoDB Persistent Volume enabled? false
mongodb.persistence.storageClass Type of storage for PVC default
mongodb.persistence.accessMode Type of access mode for PVC ReadWriteOnce
mongodb.persistence.size Disk size 8Gi
serviceType Kubernetes Service type LoadBalancer
resources CPU/Memory resource requests/limits Memory: 512Mi, CPU: 300m
persistence.enabled NodeJS persistence enabled? false
persistence.storageClass Type of storage for PVC If defined:
volume.beta.kubernetes.io/storage-class: <storageClass>
Defaults:
volume.alpha.kubernetes.io/storage-class: default
———————————————————————————————————————————————————————————————————

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,

  1. $ helm install --name my-release \
  2. --set repository=https://github.com/scotch-io/node-todo.git,mongodb.mongodbRootPassword=secretpassword \
  3. incubator/mean

The above command clones the remote git repository to the /app/ directory of the container. Additionally it sets the MongoDB root user password to secretpassword.

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

  1. $ helm install --name my-release -f values.yaml incubator/mean

Tip: You can use the default values.yaml

Persistence

The Bitnami NodeJS image stores the NodeJS application and configurations at the /app path of the container.
This storage is ephemeral and it will disappear when the pods are taken away

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.