Node.js & Bun runtime

Overview

Clever Cloud allows you to deploy any JavaScript and TypeScript application. We do support any stable version of Node.js. Learn more about Node.js release schedule. This page explains how to set up your application to run it on our service.

Create your Node.js & Bun application

To create a new Node.js & Bun application, use the Clever Cloud Console or Clever Tools:

clever create --type node

• Learn more about Clever Tools
• Learn more about Clever Cloud application deployment

Configure your Node.js & Bun application

Mandatory needs

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 a main field
• The folder /node_modules is mentioned in your .gitignore file
• You enable production mode by setting the environment variable NODE_ENV=production

Build phase

During the build phase, Clever Cloud will install your application dependencies with the selected package manager.

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",
  }
}

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.

• Use private repositories
• Manage Development Dependencies

Supported package managers

Clever Cloud supports any package manager compatible with Node.js ecosystem. The environment variable CC_NODE_BUILD_TOOL allows you to define which one you want to use to install dependencies during the build phase:

• 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
• pnpm: uses pnpm
• yarn-berry: uses Yarn
• custom: use another package manager, defined with CC_CUSTOM_BUILD_TOOL

What about Deno?

Deno is not natively supported on Clever Cloud, but you can get it using Mise, by setting a mise.toml file with the following content:

[tools]
deno = "latest"

Then it will be installed during deployment. You can replace latest with a specific version.

• Lume with Deno guide

Automatic detection

If a lock file exists in your application’s main folder, the corresponding package manager is set:

• If a bun.lock file exists, bun is used for build/run
• If a pnpm-lock.yaml file exists, pnpm is used for build/run
• If a yarn.lock file exists, and a 3.x/4.x version is declared in package.json, yarn-berry is used for build/run

To overwrite this behavior, either delete the lock file or set the CC_NODE_BUILD_TOOL environment variable.

Version management

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.

pnpm and Yarn versions

To load a specific version, set the packageManager field in your package.json file. For example, to use [email protected]:

{
  "packageManager": "[email protected]"
}

This is the default way to manage version for pnpm and Yarn when a new project is initialized. It will define the version used for dependency installation during the build phase and in run command. Yarn 1.22.22 remains the default system version included for legacy reasons.

• If CC_NODE_BUILD_TOOL is set to yarn-berry, the latest 4.x packaged version of Yarn becomes the system default
• If you use Yarn 1.x or Yarn 2.x, a deprecation warning is displayed during deployment as they’re not maintained anymore

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 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

With CC_NPM_BASIC_AUTH

Or you can set CC_NPM_BASIC_AUTH to use basic authentication

CC_NPM_BASIC_AUTH="user:password"

Define the host

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://[email protected]/<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