Testutil: add DNF5 helper function for depsolving

This will be used for testing the SBOM implementation with DNF5.

Signed-off-by: Tomáš Hozza <thozza@redhat.com>

osbuild/testutil/dnf5.py

@@ -0,0 +1,50 @@
+import tempfile
+from typing import List, Tuple
+
+import libdnf5
+from libdnf5.base import GoalProblem_NO_PROBLEM as NO_PROBLEM
+
+
+def depsolve_pkgset(
+    repo_paths: List[str],
+    pkg_include: List[str]
+) -> Tuple[libdnf5.base.Base, List[libdnf5.rpm.Package]]:
+    """
+    Perform a dependency resolution on a set of local RPM repositories.
+    """
+
+    with tempfile.TemporaryDirectory() as tempdir:
+        base = libdnf5.base.Base()
+        conf = base.get_config()
+        conf.config_file_path = "/dev/null"
+        conf.persistdir = f"{tempdir}{conf.persistdir}"
+        conf.cachedir = f"{tempdir}{conf.cachedir}"
+        conf.reposdir = ["/dev/null"]
+        conf.pluginconfpath = "/dev/null"
+        conf.varsdir = ["/dev/null"]
+
+        sack = base.get_repo_sack()
+        for idx, repo_path in enumerate(repo_paths):
+            repo = sack.create_repo(f"repo{idx}")
+            conf = repo.get_config()
+            conf.baseurl = f"file://{repo_path}"
+
+        base.setup()
+        sack.load_repos(libdnf5.repo.Repo.Type_AVAILABLE)
+
+        goal = libdnf5.base.Goal(base)
+        for pkg in pkg_include:
+            goal.add_install(pkg)
+        transaction = goal.resolve()
+
+        transaction_problems = transaction.get_problems()
+        if transaction_problems != NO_PROBLEM:
+            raise RuntimeError(f"transaction problems: {transaction.get_resolve_logs_as_strings()}")
+
+        pkgs = []
+        for tsi in transaction.get_transaction_packages():
+            pkgs.append(tsi.get_package())
+
+        # NB: return the base object as well, to workaround a bug in libdnf5:
+        # https://github.com/rpm-software-management/dnf5/issues/1748
+        return base, pkgs

test/mod/test_testutil_dnf5.py

@@ -0,0 +1,11 @@
+import os.path
+
+import pytest
+
+testutil_dnf5 = pytest.importorskip("osbuild.testutil.dnf5")
+
+
+def test_depsolve_pkgset():
+    _, pkgset = testutil_dnf5.depsolve_pkgset([os.path.abspath("./test/data/testrepos/baseos")], ["bash"])
+    assert len(pkgset) == 15
+    assert "bash" in [pkg.get_name() for pkg in pkgset]