Is it possible to completely replace a Dockerfile with a docker-compose.yml file for image building?

No, the docker-compose.yml file cannot fully replace the Dockerfile for building an image.

Dockerfile describes exactly how the image is built: which base layers to use, which commands to execute, which files to copy, etc. It is an instruction for building the image.

docker-compose.yml is intended for describing and running multi-container applications, including setting up networks, volumes, environment variables, and dependencies between services. It can specify which Dockerfile to use for building the image, but the actual build process and image description occur in the Dockerfile.

Example in docker-compose.yml for building an image from a Dockerfile:

version: '3'
services:
  app:
    build: .  # Path to Dockerfile
    ports:
      - "8080:80"

Thus, docker-compose.yml complements the Dockerfile, but does not replace it.