Node.js

Overview

Clever Cloud allows you to deploy any Node.js application. We do support any stable version of Node.js. Their release schedule is available here. This page explains how to set up your application to run it on our service.

Configure your Node.js application

Mandatory configuration

Be sure that:

• you listen on HTTP port 0.0.0.0:8080
• you have a package.json file
• your package.json either has a scripts.start or main field
• the folder /node_modules is mentioned in your .gitignore file
• you enable production mode by setting the environment variable NODE_ENV=production

About package.json

A valid package.json file should look like the following:

{
  "name" : "myApp",
  "version" : "0.1.0",
  "main" : "myApp.js",
}

or

{
  "name" : "myApp",
  "version" : "0.1.0",
  "scripts" : {
    "start" : "node myApp.js"
  }
}

You can use additional scripts as an alternative to Clever Cloud hooks; see the npm documentation. For example, scripts.preinstall, scripts.install and scripts.postinstall are executed during the build phase if defined. scripts.prestart and scripts.poststart are executed before and after the scripts.start command. Thus, your package.json can look like this:

{
  "name" : "myApp",
  "version" : "0.1.0",
  "scripts" : {
    "preinstall": "./download.sh",  // during build phase, before dependencies installation
    "postinstall": "./cleanup.sh",  // during build phase, after dependencies installation
    "prestart": "./prepare.sh",     // during run phase, before the start command
    "start" : "node myApp.js",
  }
}

Custom run command

If you need to run a custom command (or just pass options to the program), you can specify it through the CC_RUN_COMMAND environment variable. For instance, to launch scripts.start with a yarn based application, you must have CC_RUN_COMMAND="yarn start".

Dependencies

If you need some modules you can easily add some with the dependencies field in your package.json. Here is an example:

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{
  "name" : { ... },
  "engines": { ... },
  "dependencies": {
    "express": "5.x",
    "socket.io": "4.8.x",
    "underscore": "1.13.7"
  }
}

If your application has private dependencies, you can add a private SSH key.

Supported package managers

We support any package manager compatible with Node.js. The environment variable CC_NODE_BUILD_TOOL allows you to define which one you want to use. The default value is set to npm, but it can be any of these values:

• bun: uses Bun as a package manager and as a runtime
• npm or npm-install: default, uses npm install
• npm-ci: uses npm clean-install
• yarn: uses Yarn Classic (v1)
• yarn2: uses Yarn Berry (v2 or later)
• custom: use another package manager, defined with CC_CUSTOM_BUILD_TOOL

You can also deploy using Deno with additional configuration. See the Lume with Deno guide for example.

Set Node.js version

If you need a specific version or branch of Node.js, set CC_NODE_VERSION. You can use major, minor, patch version, such as 24, 23.11 or 22.15.1 for example. If this environment variable isn’t set, the latest LTS version available on Clever Cloud is used.

The end-of-life (EOL) versions are marked as such.

Bun version

If you use Bun, your application is deployed with the latest available version on Clever Cloud:

The end-of-life (EOL) versions are marked as such.

Yarn 3.x and 4.x support

With recent versions of Yarn, you need to put the global folder within your application to manage restarts from build cache. You can do it by setting YARN_GLOBAL_FOLDER to $APP_HOME/.yarncache/ for example, in the Console or through Clever Tools:

clever env set YARN_GLOBAL_FOLDER '$APP_HOME/.yarncache/'

Corepack and packageManager support

Since Node.js v14.19.0 and v16.9.0, you can use Corepack as an experimental feature to select a package manager—npm, pnpm, or yarn—and specify its version. You can do this with a simple command (e.g.: corepack use yarn@*) or the packageManager field in package.json. Always set CC_NODE_BUILD_TOOL when using pnpm or yarn, and make sure to set CC_CUSTOM_BUILD_TOOL when using pnpm.

Example: Deploy with pnpm

To deploy an application with pnpm, set the following environment variables:

CC_NODE_BUILD_TOOL="custom"
CC_PRE_BUILD_HOOK="npm install -g pnpm"
CC_CUSTOM_BUILD_TOOL="pnpm install && pnpm build"

CC_NODE_BUILD_TOOL="custom"
CC_PRE_BUILD_HOOK="corepack enable pnpm"
CC_CUSTOM_BUILD_TOOL="pnpm install && pnpm build"

This performs the following steps:

1. CC_NODE_BUILD_TOOL indicates that your applications is using a custom build tool
2. CC_PRE_BUILD_HOOK installs/enable pnpm globally
3. CC_CUSTOM_BUILD_TOOL installs the dependencies and builds the app

Depending on your stack, you may also need to add CC_RUN_COMMAND to your environment variables, with the appropriate command to run your application. For example, to deploy an Astro application in a Node.js runtime, use CC_RUN_COMMAND="pnpm start --port 8080 --host 0.0.0.0".

Development Dependencies

Development dependencies aren’t automatically installed during the deployment. You can control their installation setting CC_NODE_DEV_DEPENDENCIES environment variable to install or ignore. This variable overrides the default behavior of NODE_ENV.

Here are various scenarios:

• CC_NODE_DEV_DEPENDENCIES=install: Development dependencies are installed.
• CC_NODE_DEV_DEPENDENCIES=ignore: Development dependencies aren’t installed.
• NODE_ENV=production and CC_NODE_DEV_DEPENDENCIES=install: Development dependencies are installed.
• NODE_ENV=production and CC_NODE_DEV_DEPENDENCIES=ignore: Development dependencies aren’t installed.
• NODE_ENV=production: Package manager (npm/yarn) default behavior. Development dependencies aren’t installed.
• Neither NODE_ENV nor CC_NODE_DEV_DEPENDENCIES are defined: Package manager (npm/yarn) default behavior. Development dependencies are installed.

Use private repositories with CC_NPM_REGISTRY and NPM_TOKEN

Since April 2015, npm allows you to have private repositories. If you want to use such a feature, you only need to provide the auth token. Add it to your application through the NPM_TOKEN environment variable:

NPM_TOKEN="00000000-0000-0000-0000-000000000000"

Then, the .npmrc file is created automatically for your application, with the registry URL and the token.

//registry.npmjs.org/:_authToken=00000000-0000-0000-0000-000000000000

To authenticate to another registry (like GitHub), you can use the CC_NPM_REGISTRY environment variable to define its host.

CC_NPM_REGISTRY="npm.pkg.github.com"
NPM_TOKEN="00000000-0000-0000-0000-000000000000"

//npm.pkg.github.com/:_authToken=00000000-0000-0000-0000-000000000000

Deployment video

Automatic HTTPS redirection

You can use the X-Forwarded-Proto header to enable it.

If you are using Express.js, you can use express-sslify by adding:

app.use(enforce.HTTPS({
  trustProtoHeader: true
}));

Monitor your application with New Relic

You can use New Relic to monitor your application on Clever Cloud.

Please refer to our New Relic documentation to configure it for your application.

Troubleshooting your application

If you are often experiencing auto restart of your Node.js instance, maybe you have an application crashing that we automatically restart. To target this behavior, you can gracefully shut down with events handlers on uncaughtExeption unhandledRejection sigint and sigterm and log at this moment, so you can fix the problem.

Environment injection

Clever Cloud injects environment variables from your application settings as mentioned in setting up environment variables and is also injecting in your application production environment, those from your linked add-ons.

Custom build configurations

On Clever Cloud you can define some build configuration: like the app folder to deploy or the path to validate your application deployment is ready To do that follow the documentation here and add the environment variable you need.

To access environment variables from your code, you can use process.env.MY_VARIABLE.

Git Deployment on Clever Cloud

You need Git on your computer to deploy via this tool. Here is the official website of Git to get more information: git-scm.com

Setting up your remotes

1. The “Information” page of your app gives you your Git deployment URL, it looks like this:

   1. git+ssh://git@push.clever-cloud.com/<your_app_id>.git
   2. Copy it in your clipboard

2. Locally, under your code folder, type in git init to set up a new git repository or skip this step if you already have one

3. Add the deploy URL with git remote add <name> <your-git-deployment-url>

4. Add your files via git add <files path> and commit them via git commit -m <your commit message>

5. Now push your application on Clever Cloud with git push <name> master

Refer to git deployments for more details.

Linking a database or any other add-on to your application

By linking an application to an add-on, the application has the add-on environment variables in its own environment by default.

On add-on creation

Many add-ons do exist on Clever Cloud: refer to the full list and check add-ons dedicated pages for full instructions.

During add-on creation, an Applications screen appears, with a list of your applications. You can toggle the button to Link and click next. If you finish the process of add-on creation, the application is automatically linked to it.

Add-on already exists

In the Clever Cloud console, under the Service Dependencies menu of your application, you can use the Link add-ons dropdown menu to select the name of the add-on you want to link and use the add button to finish the process.

You can also link another application from the same page in the Clever Cloud console, using the Link applications dropdown menu.

More configuration

Need more configuration? To run a script at the end of your deployment? To add your private SSH key to access private dependencies?

Go check the Common configuration page.

You may want to have an advanced usage of your application, in which case we recommend you to read the Administrate documentation section.

If you can’t find something or have a specific need like using a non supported version of a particular software, please reach out to the support.

Enable health check during deployment

The healthcheck allows you to limit downtimes. Indeed, you can provide Clever Cloud with paths to check. If these paths return something other than 200, the deployment will fail.

Add one (or several) environment variable as such:

CC_HEALTH_CHECK_PATH=/my/awesome/path

Or

CC_HEALTH_CHECK_PATH_0=/my/awesome/path
CC_HEALTH_CHECK_PATH_1=/my/other/path

The deployment process checks all paths. All of them must reply with a 200 OK response code.

By default, when no environment variable (for ex: APP_HOME) is defined, the monitoring checks your repository root path /.

Example

Using the path listed above, below are the expected logs:

Response from GET /my/awesome/path is 200
Response from GET /my/other/path is 500
Health check failed:
- GET /my/other/path returned 500.
If the deployment fails after this message, please update your configuration and redeploy.

In this example, the first path is OK, but the second one failed. This gives you a hint on what failed in your application.

Best practice for healthcheck endpoints

To make the most of a healthcheck endpoint, have it check your critical dependencies. For example:

• execute SELECT 1 + 1; on your database
• retrieve a specific Cellar file
• ping a specific IP through a VPN