Question

A developer is configuring an AWS CodeBuild project to build a Docker container image from a Dockerfile and push it to Amazon ECR. The buildspec runs 'docker build' and 'docker push' commands, but every build fails during the 'docker build' step with an error indicating that it cannot connect to the Docker daemon. The developer has confirmed the build role has ECR permissions. What is the most likely cause and correct fix?

Accepted Answer

The CodeBuild project must have privileged mode enabled so the build container can run the Docker daemon.

Answer

The build must run on a Windows environment image because Docker builds are not supported on Linux CodeBuild images.

Answer

The buildspec must include an 'aws ecr get-login-password' command in the pre_build phase to start the Docker daemon.

Answer

The service role needs the AdministratorAccess policy attached to allow Docker daemon access.