allow to limit ansible hosts with regex

.gitignore

@@ -18,3 +18,4 @@ flake8.report
 junit*.xml
 doc/build
 .cache
+.idea/

test/inventory.yml

@@ -0,0 +1,33 @@
+all:
+  hosts:
+    s1:
+      ansible_host: 192.168.1.1
+    s2:
+      ansible_host: 192.168.1.2
+    s3:
+      ansible_host: 192.168.1.3
+    s4:
+      ansible_host: 192.168.1.4
+    s5:
+      ansible_host: 192.168.1.5
+    s6:
+      ansible_host: 192.168.1.6
+    s7:
+      ansible_host: 192.168.1.7
+    s8:
+      ansible_host: 192.168.1.8
+    s9:
+      ansible_host: 192.168.1.9
+
+  children:
+    servers:
+      hosts:
+        s1:
+        s2:
+        s3:
+        s4:
+        s5:
+        s6:
+        s7:
+        s8:
+        s9:

test/test_backends.py

@@ -523,6 +523,14 @@ def test_docker_encoding(host):
 def test_parse_hostspec(hostspec, expected):
     assert BaseBackend.parse_hostspec(hostspec) == expected
 
+@pytest.mark.parametrize(
+    "hostspec,expected",
+    [
+        ("ansible://host1", ('host1', {'connection': 'ansible'})),
+    ],
+)
+def test_init_parse_hostspec(hostspec, expected):
+    assert testinfra.backend.parse_hostspec(hostspec) == expected
 
 @pytest.mark.parametrize(
     "hostspec,pod,container,namespace,kubeconfig,context",
@@ -642,6 +650,28 @@ def test_get_hosts():
     ]
 
 
+def test_get_hosts_ansible_limit():
+    # Hosts returned by get_host must be deduplicated (by name & kwargs) and in
+    # same order as asked
+    hosts = testinfra.backend.get_backends(
+        [
+            "ansible://s%5B1-4%5D%2A?ansible_inventory=inventory.yml" # s%5B1-4%5D%2A == s[1-4]*
+        ]
+    )
+    assert [h.hostname for h in hosts] == ["s1", "s2", "s3", "s4"]
+
+def test_get_hosts_ansible_limit_from_kwargs():
+    # Hosts returned by get_host must be deduplicated (by name & kwargs) and in
+    # same order as asked
+    hosts = testinfra.backend.get_backends(
+        [
+            "ansible://all"
+        ],
+        ansible_inventory="inventory.yml",
+        ansible_limit="s[5-8]*"
+    )
+    assert [h.hostname for h in hosts] == ["s5", "s6", "s7", "s8"]
+
 @pytest.mark.testinfra_hosts(*HOSTS)
 def test_command_deadlock(host):
     # Test for deadlock when exceeding Paramiko transport buffer (2MB)

testinfra/backend/__init__.py

@@ -96,6 +96,7 @@ def get_backends(
     backends = {}
     for hostspec in hosts:
         host, kw = parse_hostspec(hostspec)
+        host = urllib.parse.unquote(host)
         for k, v in kwargs.items():
             kw.setdefault(k, v)
         connection = kw.get("connection")

testinfra/backend/ansible.py

@@ -87,4 +87,15 @@ def get_variables(self) -> dict[str, Any]:
     @classmethod
     def get_hosts(cls, host: str, **kwargs: Any) -> list[str]:
         inventory = kwargs.get("ansible_inventory")
-        return AnsibleRunner.get_runner(inventory).get_hosts(host or "all")
+        hosts = AnsibleRunner.get_runner(inventory).get_hosts(host or "all")
+        limit = kwargs.get("ansible_limit")
+        if limit:
+            # Filter hosts based on the limit expression
+            from ansible.parsing.dataloader import DataLoader
+            from ansible.inventory.manager import InventoryManager
+
+            loader = DataLoader()
+            inventory_manager = InventoryManager(loader=loader, sources=inventory)
+            return list(map(lambda h: h.address, inventory_manager.get_hosts(pattern=limit)))
+        else:
+            return hosts

testinfra/plugin.py

@@ -107,6 +107,12 @@ def pytest_addoption(parser: pytest.Parser) -> None:
         dest="nagios",
         help="Nagios plugin",
     )
+    group.addoption(
+        "--ansible-limit",
+        action="store_true",
+        dest="ansible_limit",
+        help="Limit to specific hosts using the same syntax as Ansible's --limit option.",
+    )
 
 
 def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
@@ -126,6 +132,7 @@ def pytest_generate_tests(metafunc: pytest.Metafunc) -> None:
             sudo_user=metafunc.config.option.sudo_user,
             ansible_inventory=metafunc.config.option.ansible_inventory,
             force_ansible=metafunc.config.option.force_ansible,
+            ansible_limit=metafunc.config.option.ansible_limit,
         )
         params = sorted(params, key=lambda x: x.backend.get_pytest_id())
         ids = [e.backend.get_pytest_id() for e in params]