testutil: add helper function for depsolving pkgset with DNF4

This will be useful for testing SBOM implementations.

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

osbuild/testutil/dnf4.py

@@ -0,0 +1,36 @@
+import tempfile
+from typing import List, Optional
+
+import dnf
+
+
+def depsolve_pkgset(
+    repo_paths: List[str],
+    pkg_include: List[str],
+    pkg_exclude: Optional[List[str]] = None
+) -> List[dnf.package.Package]:
+    """
+    Perform a dependency resolution on a set of local RPM repositories.
+    """
+
+    with tempfile.TemporaryDirectory() as tempdir:
+        conf = dnf.conf.Conf()
+        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"]
+
+        base = dnf.Base(conf)
+
+        for idx, repo_path in enumerate(repo_paths):
+            repo = dnf.repo.Repo(f"repo{idx}", conf)
+            repo.baseurl = f"file://{repo_path}"
+            base.repos.add(repo)
+
+        base.fill_sack(load_system_repo=False)
+
+        base.install_specs(pkg_include, pkg_exclude)
+        base.resolve()
+        return base.transaction.install_set