CI/CD in Node.js with CircleCI

Run Node.js CI/CD in CircleCI with an encrypted .env.vault file

Initial setup

Create a build.js file. It's a very simple build script that outputs 'Hello World'.

build.js

// build.js
console.log(`Hello ${process.env.HELLO}`)

Create a package.json file.

package.json

{
  "scripts": {
    "build": "node build.js"
  }
}

Create a .circleci/config.yml file.

.circleci/config.yml

# .circleci/config.yml
version: 2.1
orbs:
  node: circleci/[email protected]
jobs:
  build:
    docker:
      - image: cimg/base:2021.04
    steps:
      - checkout
      - node/install
      - node/install-packages
      - run:
          name: Run build
          command: npm run build

Run npm install to include the package-lock.json file.

npm install

Commit all that to code and push to GitHub. Then connect your GitHub repo to CircleCI.

app.circleci.com

app.circleci.com

app.circleci.com

Once pushed, the CircleCI build will say 'Hello undefined' as it doesn't have a way to access the environment variable yet. Let's do that next.

Install dotenv

Install dotenv.

npm install dotenv --save # Requires dotenv >= 16.1.0

Create a .env file in the root of your project.

.env

# .env
HELLO="World"

As early as possible in your application, import and configure dotenv.

build.js

// build.js
require('dotenv').config()
console.log(process.env) // remove this after you've confirmed it is working

console.log(`Hello ${process.env.HELLO}`)

Try running it locally.

node build.js
{
  ...
  HELLO: 'World'
}
Hello World

Perfect. process.env now has the keys and values you defined in your .env file.

That covers local simulation of the CI. Let's solve for the real CI environment next.

Build .env.vault

Push your latest .env file changes and edit your CI secrets. Learn more about syncing

npx dotenv-vault@latest push
npx dotenv-vault@latest open ci

Use the UI to configure those secrets per environment.

dotenv.org

Then build your encrypted .env.vault file.

npx dotenv-vault@latest build

Its contents should look something like this.

.env.vault

#/-------------------.env.vault---------------------/
#/         cloud-agnostic vaulting standard         /
#/   [how it works](https://dotenv.org/env-vault)   /
#/--------------------------------------------------/

# development
DOTENV_VAULT_DEVELOPMENT="/HqNgQWsf6Oh6XB9pI/CGkdgCe6d4/vWZHgP50RRoDTzkzPQk/xOaQs="
DOTENV_VAULT_DEVELOPMENT_VERSION=2

# ci
DOTENV_VAULT_CI="x26PuIKQ/xZ5eKrYomKngM+dO/9v1vxhwslE/zjHdg3l+H6q6PheB5GVDVIbZg=="
DOTENV_VAULT_CI_VERSION=2

Set DOTENV_KEY

Fetch your CI DOTENV_KEY.

npx dotenv-vault@latest keys ci
# outputs: dotenv://:[email protected]/vault/.env.vault?environment=ci

Set DOTENV_KEY on CircleCI.

app.circleci.com

Build CI

Commit those changes safely to code and rerun the build.

That's it! On rerun, your .env.vault file will be decrypted and its CI secrets injected as environment variables – just in time.

app.circleci.com build

It will say Hello ci.

app.circleci.com build

You'll know things worked correctly when you see 'Loading env from encrypted .env.vault' in your logs. If a DOTENV_KEY is not set (for example when developing on your local machine) it will fall back to standard dotenv functionality.