chore: add verifier skeleton

Add a skeleton for the verifier module to allow multiple people to
work on it later.

Signed-off-by: Yftach Herzog <[email protected]>

verify-rpms/rpm_verifier.py

@@ -0,0 +1,49 @@
+#!/usr/bin/env python3
+
+from pathlib import Path
+from typing import Callable
+
+import click
+
+
+def get_rpmdb(container_image: str) -> Path:
+    raise NotImplementedError()
+
+
+def get_rpms(rpmdb: Path) -> list[str]:
+    raise NotImplementedError()
+
+
+def get_unsigned_rpms(rpms: list[str], verifier: Callable[[str], bool]) -> list[str]:
+    return [rpm for rpm in rpms if verifier(rpm)]
+
+
+def is_rpm_unsigned(rpm: str) -> bool:
+    raise NotImplementedError()
+
+
+def generate_output(unsigned_rpms: dict[str, list[str]]) -> bool:
+    raise NotImplementedError()
+
+
+@click.command()
+@click.option(
+    "--container-image",
+    help="Reference to container image",
+    type=str,
+    multiple=True,
+)
+def main(container_image: list[str]):
+    rpms_dbs: dict[str, Path] = {img: get_rpmdb(img) for img in container_image}
+    rpms_list: dict[str, list[str]] = {
+        img: get_rpms(rpmdb) for (img, rpmdb) in rpms_dbs.items()
+    }
+    unsigned_rpms: dict[str, list[str]] = {
+        img: get_unsigned_rpms(rpms, is_rpm_unsigned)
+        for (img, rpms) in rpms_list.items()
+    }
+    generate_output(unsigned_rpms)
+
+
+if __name__ == "__main__":
+    main()  # pylint: disable=no-value-for-parameter