Introduce rpms.get_leapp_packages library function

This function can be used as leapp-installation-packages-getter.
Refactoring of other actors using it will be done later.

repos/system_upgrade/common/libraries/rpms.py

@@ -1,4 +1,5 @@
 from leapp.libraries import stdlib
+from leapp.libraries.common.config.version import get_source_major_version
 from leapp.models import InstalledRPM
 
 
@@ -114,3 +115,36 @@ def check_file_modification(config):
     """
     output = _read_rpm_modifications(config)
     return _parse_config_modification(output, config)
+
+
+def get_leapp_packages(source_version=None, component=None, include_deps=False):
+    """
+    Get list of leapp packages.
+
+    :param source_version: a list or string specifying source_versions. If not defined then all packages
+        for current source_target_version will be returned.
+    :param component: a list or string specifying leapp components. If defined then only packages related
+        to the specific component will be returned.
+    :param include_deps: a flag to control whether deps meta packages are to be filtered out.
+    """
+    res = set()
+    # NOTE(ivasilev) mapping has the format component: {source_version: [pkg1, pkg2, ..]}
+    component_map = {'framework': {'7': ['leapp', 'leapp-deps', 'python2-leapp'],
+                                   '8': ['leapp', 'leapp-deps', 'python3-leapp']},
+                     'repository': {'7': ['leapp-upgrade-el7toel8', 'leapp-upgrade-el7toel8-deps'],
+                                    '8': ['leapp-upgrade-el8toel9', 'leapp-upgrade-el8toel9-deps']},
+                     'snactor': {'7': ['snactor'],
+                                 '8': ['snactor']}}
+    source_versions = [source_version] if isinstance(source_version, str) else (source_version or
+                                                                                [get_source_major_version()])
+    components = [component] if isinstance(component, str) else component or list(component_map.keys())
+    for comp in components:
+        for src_version in source_versions:
+            try:
+                res.update(component_map[comp][src_version])
+            except KeyError:
+                continue
+    if not include_deps:
+        # filter out deps packages
+        return sorted([pkg for pkg in res if not pkg.endswith('-deps')])
+    return sorted(res)

repos/system_upgrade/common/libraries/tests/test_rpms.py

@@ -1,4 +1,8 @@
-from leapp.libraries.common.rpms import _parse_config_modification
+import pytest
+
+from leapp.libraries.common.rpms import _parse_config_modification, get_leapp_packages
+from leapp.libraries.common.testutils import CurrentActorMocked
+from leapp.libraries.stdlib import api
 
 
 def test_parse_config_modification():
@@ -30,3 +34,20 @@ def test_parse_config_modification():
         "S.5....T.  c /etc/ssh/sshd_config",
     ]
     assert _parse_config_modification(data, "/etc/ssh/sshd_config")
+
+
+@pytest.mark.parametrize('source_version,component,include_deps,result', [
+   (None, None, False, ['leapp', 'python3-leapp', 'leapp-upgrade-el8toel9', 'snactor']),
+   (None, None, True, ['leapp', 'leapp-deps', 'python3-leapp', 'leapp-upgrade-el8toel9',
+                       'leapp-upgrade-el8toel9-deps', 'snactor']),
+   ('7', None, False, ['leapp', 'python2-leapp', 'leapp-upgrade-el7toel8', 'snactor']),
+   (['7', '8'], None, False, ['leapp', 'python2-leapp', 'leapp-upgrade-el7toel8',
+                              'python3-leapp', 'leapp-upgrade-el8toel9', 'snactor']),
+   ('nosuchversion', None, False, []),
+   ('8', 'framework', False, ['leapp', 'python3-leapp']),
+   ('8', 'framework', True, ['leapp', 'python3-leapp', 'leapp-deps']),
+   ('8', 'nosuchcomponent', True, []),
+   ])
+def test_get_leapp_packages(source_version, component, include_deps, result, monkeypatch):
+    monkeypatch.setattr(api, 'current_actor', CurrentActorMocked(arch='x86_64', src_ver='8.9', dst_ver='9.3'))
+    assert set(get_leapp_packages(source_version, component, include_deps)) == set(result)