chore(RHTAPWATCH-640): add get_rpmdb implementation

Add implementation and tests for get_rpmdb

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

tests/test_rpm_verifier.py

@@ -1,12 +1,26 @@
 """Test rpm_verifier.py end-to-end"""
 
+from pathlib import Path
 from unittest.mock import MagicMock, call, create_autospec, sentinel
 
 import pytest
 from pytest import MonkeyPatch
 
 from verify_rpms import rpm_verifier
-from verify_rpms.rpm_verifier import ImageProcessor, generate_output
+from verify_rpms.rpm_verifier import ImageProcessor, generate_output, get_rpmdb
+
+
+def test_get_rpmdb(tmp_path: Path) -> None:
+    """Test get_rpmdb"""
+    image = "my-image"
+    mock_runner = MagicMock()
+    out = get_rpmdb(
+        container_image=image,
+        target_dir=tmp_path,
+        runner=mock_runner,
+    )
+    assert mock_runner.call_count == 1
+    assert out == tmp_path
 
 
 class TestMain:

verify_rpms/rpm_verifier.py

@@ -22,7 +22,20 @@ class ProcessedImage:
 
 def get_rpmdb(container_image: str, target_dir: Path, runner: Callable = run) -> Path:
     """Extract RPM DB from a given container image reference"""
-    raise NotImplementedError()
+    runner(
+        [
+            "oc",
+            "image",
+            "extract",
+            container_image,
+            "--path",
+            f"/var/lib/rpm/:{target_dir}",
+        ],
+        capture_output=True,
+        text=True,
+        check=True,
+    )
+    return target_dir
 
 
 def get_unsigned_rpms(rpmdb: Path, runner: Callable = run) -> list[str]: