nx/docs/shared/monorepo-ci-circle-ci.md

Configuring CI Using Circle CI and Nx

Below is an example of a Circle CI setup, building, and testing only what is affected.

version: 2.1

orbs:
  nx: nrwl/nx@1.6.2

jobs:
  main:
    docker:
      - image: cimg/node:lts-browsers
    steps:
      - checkout
      # This line enables distribution
      # The "--stop-agents-after" is optional, but allows idle agents to shut down once the "e2e-ci" targets have been requested
      - run: npx nx-cloud start-ci-run --distribute-on="5 linux-medium-js" --stop-agents-after="e2e-ci"
      - run: npm ci

      - nx/set-shas

      - run: npx nx-cloud record -- nx format:check
      - run: npx nx affected --base=$NX_BASE --head=$NX_HEAD -t lint test build e2e-ci
workflows:
  build:
    jobs:
      - main

Get the Commit of the Last Successful Build

CircleCI can track the last successful run on the main branch and use this as a reference point for the BASE. The Nx Orb provides a convenient implementation of this functionality, which you can drop into your existing CI workflow. Specifically, for push commits, nx/set-shas populates the $NX_BASE environment variable with the commit SHA of the last successful run.

To understand why knowing the last successful build is important for the affected command, check out the in-depth explanation in Orb's docs.

Using CircleCI in a private repository

To use the Nx Orb with a private repository on your main branch, you need to grant the orb access to your CircleCI API. Create an environment variable called CIRCLE_API_TOKEN in the context of the project.

{% callout type="warning" title="Caution" %} It should be a user token, not the project token. {% /callout %}