osbuild/solver/dnf.py: Add support for DNF variables for osbuild repos

Signed-off-by: Josue David Hernandez Gutierrez <josue.d.hernandez@oracle.com>

.mypy.ini

@@ -15,6 +15,9 @@ ignore_missing_imports = True
 [mypy-dnf.*]
 ignore_missing_imports = True
 
+[mypy-libdnf.*]
+ignore_missing_imports = True
+
 [mypy-libdnf5.*]
 ignore_missing_imports = True
 

osbuild/solver/dnf.py

@@ -10,6 +10,8 @@ from typing import Dict, List
 
 import dnf
 import hawkey
+import libdnf
+from dnf.i18n import ucd
 
 from osbuild.solver import (
     DepsolveError,
@@ -68,6 +70,12 @@ class DNF(SolverBase):
         self.base.conf.substitutions['basearch'] = dnf.rpm.basearch(arch)
         self.base.conf.substitutions['releasever'] = releasever
 
+        # variables substitution is only available when root_dir is provided
+        if root_dir:
+            # This sets the varsdir to ("{root_dir}/etc/yum/vars/", "{root_dir}/etc/dnf/vars/") for custom variable
+            # substitution (e.g. CentOS Stream 9's $stream variable)
+            self.base.conf.substitutions.update_from_etc(root_dir)
+
         if hasattr(self.base.conf, "optional_metadata_types"):
             # the attribute doesn't exist on older versions of dnf; ignore the option when not available
             self.base.conf.optional_metadata_types.extend(arguments.get("optional-metadata", []))
@@ -77,15 +85,11 @@ class DNF(SolverBase):
         try:
             req_repo_ids = set()
             for repo in repos:
-                self.base.repos.add(self._dnfrepo(repo, self.base.conf))
+                self.base.repos.add(self._dnfrepo(repo, self.base.conf, root_dir is not None))
                 # collect repo IDs from the request to separate them from the ones loaded from a root_dir
                 req_repo_ids.add(repo["id"])
 
             if root_dir:
-                # This sets the varsdir to ("{root_dir}/etc/yum/vars/", "{root_dir}/etc/dnf/vars/") for custom variable
-                # substitution (e.g. CentOS Stream 9's $stream variable)
-                self.base.conf.substitutions.update_from_etc(root_dir)
-
                 repos_dir = os.path.join(root_dir, "etc/yum.repos.d")
                 self.base.conf.reposdir = repos_dir
                 self.base.read_all_repos()
@@ -110,21 +114,27 @@ class DNF(SolverBase):
         self.license_index_path = license_index_path
 
     @staticmethod
-    def _dnfrepo(desc, parent_conf=None):
+    def _dnfrepo(desc, parent_conf=None, subs_links=False):
         """Makes a dnf.repo.Repo out of a JSON repository description"""
 
         repo = dnf.repo.Repo(desc["id"], parent_conf)
+        config = libdnf.conf.ConfigParser
 
         if "name" in desc:
             repo.name = desc["name"]
 
+        def subs(basestr):
+            if subs_links and parent_conf:
+                return config.substitute(ucd(basestr), parent_conf.substitutions)
+            return basestr
+
         # at least one is required
         if "baseurl" in desc:
-            repo.baseurl = desc["baseurl"]
+            repo.baseurl = [subs(repo) for repo in desc["baseurl"]]
         elif "metalink" in desc:
-            repo.metalink = desc["metalink"]
+            repo.metalink = subs(desc["metalink"])
         elif "mirrorlist" in desc:
-            repo.mirrorlist = desc["mirrorlist"]
+            repo.mirrorlist = subs(desc["mirrorlist"])
         else:
             raise ValueError("missing either `baseurl`, `metalink`, or `mirrorlist` in repo")
 

tools/test/test_depsolve.py

@@ -1544,6 +1544,74 @@ def test_depsolve_config_combos(tmp_path, repo_servers, dnf_config, detect_fn):
                 assert res["solver"] == "dnf"
 
 
+def set_config_dnfvars(baseurl, dnfvars):
+    for j, url in enumerate(baseurl):
+        for var, value in dnfvars.items():
+            if value in url:
+                baseurl[j] = url.replace(value, f"${var}")
+    return baseurl
+
+
+def create_dnfvars(root_dir, dnfvars):
+    vars_dir = root_dir / "etc/dnf/vars"
+    vars_dir.mkdir(parents=True)
+
+    for var, value in dnfvars.items():
+        var_path = vars_dir / var
+        var_path.write_text(value, encoding="utf8")
+
+
+@pytest.mark.parametrize("use_dnfvars", [True, False], ids=["with_dnfvars", "without_dnfvars"])
+@pytest.mark.parametrize("dnf_config, detect_fn", [
+    ({}, assert_dnf),
+    ({"use_dnf5": False}, assert_dnf),
+    ({"use_dnf5": True}, assert_dnf5),
+], ids=["no-config", "dnf4", "dnf5"])
+def test_depsolve_dnfvars(tmp_path, repo_servers, dnf_config, detect_fn, use_dnfvars):
+    try:
+        detect_fn()
+    except RuntimeError as e:
+        pytest.skip(str(e))
+
+    test_case = depsolve_test_case_basic_2pkgs_2repos
+    transactions = test_case["transactions"]
+    repo_configs = get_test_case_repo_configs(test_case, repo_servers)
+    root_dir = None
+
+    for index, config in enumerate(repo_configs):
+        repo_configs[index]["baseurl"] = set_config_dnfvars(config["baseurl"], {"var": "localhost"})
+
+    if use_dnfvars:
+        create_dnfvars(tmp_path, {"var": "localhost"})
+        root_dir = str(tmp_path)
+
+    res, exit_code = depsolve(transactions, tmp_path.as_posix(), dnf_config, repo_configs, root_dir=root_dir)
+
+    if not use_dnfvars:
+        assert exit_code != 0
+        assert res["kind"] == "RepoError"
+        assert re.match(
+            "There was a problem reading a repository: Failed to download metadata", res["reason"], re.DOTALL)
+        return
+
+    assert exit_code == 0
+    assert {pkg["name"] for pkg in res["packages"]} == test_case["results"]["packages"]
+    assert res["repos"].keys() == test_case["results"]["reponames"]
+
+    # modules is optional here as the dnf5 depsolver never returns any modules
+    assert res.get("modules", {}).keys() == test_case["results"].get("modules", set())
+
+    for repo in res["repos"].values():
+        assert repo["gpgkeys"] == [TEST_KEY + repo["id"]]
+        assert repo["sslverify"] is False
+
+    use_dnf5 = dnf_config.get("use_dnf5", False)
+    if use_dnf5:
+        assert res["solver"] == "dnf5"
+    else:
+        assert res["solver"] == "dnf"
+
+
 # pylint: disable=too-many-branches
 @pytest.mark.parametrize("custom_license_db", [None, "./test/data/spdx/custom-license-index.json"])
 @pytest.mark.parametrize("with_sbom", [False, True])