[CDK Pipelines] Asset bundling (running Docker during 'synth') doesn't work

I’m trying out new CDK Pipelines in developer preview. I have a question on how to bundle assets that are using docker container during the build process. Currently during “synth_action”, getting following error:

Reproduction Steps

pipelines.CdkPipeline(self,
                       "Pipeline",
                       pipeline_name="Test",
                       cloud_assembly_artifact=cloud_assembly_artifact,
                       source_action=codepipeline_actions.CodeCommitSourceAction(
                               action_name="CodeCommit_Source",
                               repository=code,
                               branch="cdkpipeline",
                              output=source_artifact),
                       synth_action=pipelines.SimpleSynthAction.standard_npm_synth()
                               source_artifact=source_artifact,
                               cloud_assembly_artifact=cloud_assembly_artifact,
                               build_command="npx cdk synth")

Error Log

stderr: docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.   
See 'docker run --help'. 
at AssetStaging.bundle (/tmp/jsii-kernel-O8ZKbG/node_modules/@aws-cdk/core/lib/asset-staging.js:121:19) 
at new AssetStaging (/tmp/jsii-kernel-O8ZKbG/node_modules/@aws-cdk/core/lib/asset-staging.js:38:35)
 at new Asset (/tmp/jsii-kernel-O8ZKbG/node_modules/@aws-cdk/aws-s3-assets/lib/asset.js:21:25)

Environment

• CDK CLI Version: 1.51.0
• Module Version: 1.51.0
• Node.js Version: v14.5.0
• OS: OSX Mojave
• Language (Version): Python (3.7.3)

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This is 🐛 Bug Report

[vermontkidsdata]

We worked it out. We ended up doing an npm install of esbuild locally in package.json. Apparently if you don’t have it locally, it tries to use docker.

[eladb]

Since bundling is a framework feature, We should automatically identify if docker is required for asset bundling and configure your synth environment accordingly.