cdk synth: spawnSync docker ENOENT because cdk is not looking at the right directory

[MD]

Describe the bug

When using cdk synth to bundle my lambda code (in python) CDK throws spawnSync docker ENOENT

Expected Behavior

cdk to look in the right location /Applications/Docker.app/Contents/Resources/bin/docker or look into possible locations.

Current Behavior

Currently cdk is looking at the wrong directory which caused the confusing error of spawnSync docker ENOENT

Reproduction Steps

OS: Macos 13.6.7 (22G720)
Docker: Docker Desktop 4.31.0 (153195)
CDK: 2.146.0 (b368c78)

new lambda.Function(this, 'myFn', {
      runtime: lambda.Runtime.PYTHON_3_12,
      handler: 'main.handler',
      code: lambda.Code.fromAsset(path.join(__dirname, './src'), {
        bundling: {
          image: lambda.Runtime.PYTHON_3_12.bundlingImage,
          command: [
            'bash', '-c',
            'pip install -r requirements.txt -t /asset-output && cp -au . /asset-output'
          ],
        },
      }),
    });

Possible Solution

ln -s '/Applications/Docker.app/Contents/Resources/bin/docker' '/usr/local/bin/docker'

This will solve the issue.

Additional Information/Context

No response

CDK CLI Version

2.146.0

Framework Version

No response

Node.js Version

v22.1.0

OS

Macos 13.6.7 (22G720)

Language

TypeScript

Language Version

No response

Other information

Searching for this message can be misleading as 99% of people suggesting installing esbuild and things related to that. But the point is this spawnSync xyz ENOENT just means the xyz is missing. I hope this will save some people some time. And the issue is fixed in future.

[Shailja Khurana]

Hi @damshenas , thanks for reaching out. I found previously filed similar issue-

Issue - #22997
Suggested solution - #22997 (comment)

Could you please check if this is the exact condition you are running into and the solution might help ??

[MD]

Hi @khushail, thanks for the follow up. Short answer is no, it does not help. Long answer is that, unfortunately the solution in the other issue does not fix my problem. In my case, there is nothing needed to be installed. Docker is already there but cdk can not find it. I also posted the solution that worked for me, but I think CDK can do better.

[Shailja Khurana]

Thanks @damshenas for the confirmation.

[Pahud Hsieh]

@damshenas

I guess this is how CDK finds the docker CLI

aws-cdk/packages/cdk-assets/lib/private/docker.ts

Lines 273 to 275 in b196b13

 function getDockerCmd(): string { 
   return process.env.CDK_DOCKER ?? 'docker'; 
 } 

Looks like it won't search /Applications/Docker.app/Contents/Resources/bin/docker

Can you try which docker and see if it returns /Applications/Docker.app/Contents/Resources/bin/docker?

And, is /Applications/Docker.app/Contents/Resources/bin in your $PATH?

[MD]

@pahud indeed that path is what which docker returns. It is not in the $PATH. I checked with another laptop (arm) and it also did not have it in the $PATH (but cdk worked fine there). Seems adding those directories to $PATH is not common in Mac.

Logically, adding the path to $PATH should also fix the issue. But ideally CDK should be able to work out of the box on all Macs.