How to Mock Docker Image Non-Root User in Python

from pathlib import Path


class DockerImageMock:
    def __init__(self, name, tag):
        self.name = name
        self.tag = tag
        self.layers = []
        self.user = "root"

    def add_file(self, path, content):
        self.layers.append({"file": path, "content": content})

    def set_user(self, username, uid, gid, home):
        self.user = username
        self.layers.append({
            "user": {
                "name": username,
                "uid": uid,
                "gid": gid,
                "home": home
            }
        })

    def inspect(self):
        last_user_layer = self.layers[-1] if self.layers and "user" in self.layers[-1] else None
        return {
            "image": f"{self.name}:{self.tag}",
            "layers_count": len(self.layers),
            "runs_as_uid": last_user_layer["user"]["uid"] if last_user_layer else 0,
            "runs_as_gid": last_user_layer["user"]["gid"] if last_user_layer else 0,
            "home_dir": last_user_layer["user"]["home"] if last_user_layer else "/root",
            "is_secure": self.user != "root" and bool(last_user_layer)
        }


if __name__ == "__main__":
    image = DockerImageMock("python-app", "v1.0")
    image.add_file("/app/app.py", "print('hello')")
    image.set_user("appuser", 1001, 1001, "/home/appuser")

    print(image.inspect())