New Docker-based Parcel Build does not work on CircleCI (and likely other CI platforms)

In 1.38.0, the build was moved into a docker container by this PR: https://github.com/aws/aws-cdk/pull/7169

This is causing builds to fail on our CircleCI platform used for continuous delivery of CDK changes.

The issue

You can see the error in the CircleCI interface here: https://app.circleci.com/pipelines/github/blimmer/cdk-parcel-docker-circleci-issue/4/workflows/a4808b45-a04c-48af-851f-960f888518fd/jobs/7

We can easily start up docker-in-docker by using Circle’s setup_remote_docker command.

However, when the parcel image tries to run lscpu, the failure causes the build to break.

#!/bin/bash -eo pipefail
npx cdk synth

Failed to build file at /home/circleci/project/lib/index.ts: Error: [Status 1] stdout: 🚨  No entries found.

    at Bundler.bundle (/usr/local/share/.config/yarn/global/node_modules/parcel-bundler/src/Bundler.js:275:17)

stderr: /bin/sh: lscpu: not found

Subprocess exited with error 1
Exited with code exit status 1
CircleCI received exit code 1

There are a number of issues on the parcel issue tracker about this issue on CI platforms: https://github.com/parcel-bundler/parcel/issues?q=is%3Aissue+sort%3Aupdated-desc+lscpu+is%3Aclosed

Reproduction Steps

I’ve created this example repo to show the problem: https://github.com/blimmer/cdk-parcel-docker-circleci-issue

Error Log

Failed to build file at /home/circleci/project/lib/index.ts: Error: [Status 1] stdout: 🚨  No entries found.

    at Bundler.bundle (/usr/local/share/.config/yarn/global/node_modules/parcel-bundler/src/Bundler.js:275:17)

stderr: /bin/sh: lscpu: not found

Environment

• CLI Version : 1.38.0
• Framework Version: 1.38.0
• OS : MacOS / Ubuntu (on CircleCI)
• Language : English

Other

A fix

I can confirm that passing the PARCEL_WORKERS environment variable to the docker run parcel-bundler image resolves the problem. I got the idea to try that from this comment on the parcel side: https://github.com/parcel-bundler/parcel/issues/133#issuecomment-619991475

I used CircleCI’s SSH feature to interactively test this.

circleci@0d67793e2a50:~/project$ docker run parcel-bundler
Server running at http://localhost:1234
/bin/sh: lscpu: not found
🚨  No entries found.
    at Bundler.bundle (/usr/local/share/.config/yarn/global/node_modules/parcel-bundler/src/Bundler.js:275:17)
    at async Bundler.serve (/usr/local/share/.config/yarn/global/node_modules/parcel-bundler/src/Bundler.js:842:7)
    at async Command.bundle (/usr/local/share/.config/yarn/global/node_modules/parcel-bundler/src/cli.js:241:20)

no errors when passing the PARCEL_WORKERS param.

circleci@0d67793e2a50:~/project$ docker run parcel-bundler -e PARCEL_WORKERS=2

Suggestion

Most all CI platforms set the CI environment variable to true. Maybe if CI is set, CDK automatically passes the PARCEL_WORKERS parameter in the docker run args?

https://github.com/aws/aws-cdk/pull/7169/files#diff-30cb98bb231179d8900591911d5cc8a4R75-R80

Alternatively, you could try to fix this problem in the docker image itself if lscpu is not present.

---

This is 🐛 Bug Report

[blimmer]

For others that might be running into this problem in CircleCI, I highly recommend switching from the Docker executor to the Machine executor. Even with the improvements referenced in this ticket, there are still issues with how CircleCI runs docker-in-docker that causes tons of headaches with lambda bundling.

Simply change your job definition from something like this:

docker:
  - image: circleci/node:lts

to using a machine executor like this:

machine:
  image: ubuntu-1604:202004-01

[TLadd]

Ended up here because I was having trouble getting our cdk deploy running in CircleCI. Can confirm that switching to the machine executor still works.