[PR #11678/d06c83eb backport][stable-12] etcd3: re-enable and fix tests, add unit tests (#11680)

etcd3: re-enable and fix tests, add unit tests (#11678)

* etcd3: re-enable and fix tests, add unit tests

- Add unit tests for community.general.etcd3 module (12 tests covering
  state=present/absent, idempotency, check mode, and error paths)
- Fix integration test setup: update etcd binary to v3.6.9 (from v3.2.14),
  download from GitHub releases, add health-check retry loop after start
- Work around etcd3 Python library incompatibility with protobuf >= 4.x
  by setting PROTOCOL_BUFFERS_PYTHON_IMPLEMENTATION=python
- Update to FQCNs throughout integration tests
- Re-enable both etcd3 and lookup_etcd3 integration targets

Fixes https://github.com/ansible-collections/community.general/issues/322



* improve use of multiple context managers

---------


(cherry picked from commit d06c83eb68)

Co-authored-by: Alexei Znamensky <103110+russoz@users.noreply.github.com>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit/plugins/modules/test_etcd3.py

@@ -0,0 +1,221 @@
+# Copyright (c) 2026, Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from __future__ import annotations
+
+import json
+from unittest.mock import MagicMock
+
+import pytest
+from ansible_collections.community.internal_test_tools.tests.unit.plugins.modules.utils import set_module_args
+
+from ansible_collections.community.general.plugins.modules import etcd3 as etcd3_module
+
+BASE_ARGS = {
+    "key": "foo",
+    "value": "bar",
+    "state": "present",
+    "host": "localhost",
+    "port": 2379,
+}
+
+
+@pytest.fixture
+def fake_etcd3(mocker):
+    """Inject a mock etcd3 library into the module namespace and enable HAS_ETCD."""
+    mock_lib = MagicMock()
+    mocker.patch.object(etcd3_module, "etcd3", mock_lib, create=True)
+    mocker.patch.object(etcd3_module, "HAS_ETCD", True)
+    return mock_lib
+
+
+def make_client(fake_etcd3, existing_value=None):
+    """Configure fake_etcd3.client() to return a mock with get() returning the given value."""
+    mock_client = MagicMock()
+    if existing_value is not None:
+        mock_client.get.return_value = (existing_value.encode(), MagicMock())
+    else:
+        mock_client.get.return_value = (None, None)
+    fake_etcd3.client.return_value = mock_client
+    return mock_client
+
+
+# ---------------------------------------------------------------------------
+# state=present
+# ---------------------------------------------------------------------------
+
+
+def test_present_new_key(capfd, fake_etcd3):
+    """state=present with a new key: should put and report changed."""
+    mock_client = make_client(fake_etcd3, existing_value=None)
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is True
+    assert result["key"] == "foo"
+    mock_client.put.assert_called_once_with("foo", "bar")
+
+
+def test_present_same_value(capfd, fake_etcd3):
+    """state=present with existing key and same value: no change."""
+    mock_client = make_client(fake_etcd3, existing_value="bar")
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is False
+    assert result["old_value"] == "bar"
+    mock_client.put.assert_not_called()
+
+
+def test_present_different_value(capfd, fake_etcd3):
+    """state=present with existing key and different value: should put and report changed."""
+    mock_client = make_client(fake_etcd3, existing_value="old_value")
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is True
+    assert result["old_value"] == "old_value"
+    mock_client.put.assert_called_once_with("foo", "bar")
+
+
+# ---------------------------------------------------------------------------
+# state=absent
+# ---------------------------------------------------------------------------
+
+
+def test_absent_existing_key(capfd, fake_etcd3):
+    """state=absent with existing key: should delete and report changed."""
+    mock_client = make_client(fake_etcd3, existing_value="bar")
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, state="absent")):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is True
+    mock_client.delete.assert_called_once_with("foo")
+
+
+def test_absent_nonexistent_key(capfd, fake_etcd3):
+    """state=absent with key not present: no change."""
+    mock_client = make_client(fake_etcd3, existing_value=None)
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, state="absent")):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is False
+    mock_client.delete.assert_not_called()
+
+
+# ---------------------------------------------------------------------------
+# check mode
+# ---------------------------------------------------------------------------
+
+
+def test_present_check_mode_new_key(capfd, fake_etcd3):
+    """state=present in check mode with new key: reports changed but no actual put."""
+    mock_client = make_client(fake_etcd3, existing_value=None)
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, _ansible_check_mode=True)):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is True
+    mock_client.put.assert_not_called()
+
+
+def test_present_check_mode_same_value(capfd, fake_etcd3):
+    """state=present in check mode with same value: no change, no put."""
+    mock_client = make_client(fake_etcd3, existing_value="bar")
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, _ansible_check_mode=True)):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is False
+    mock_client.put.assert_not_called()
+
+
+def test_absent_check_mode_existing_key(capfd, fake_etcd3):
+    """state=absent in check mode with existing key: reports changed but no actual delete."""
+    mock_client = make_client(fake_etcd3, existing_value="bar")
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, state="absent", _ansible_check_mode=True)):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is True
+    mock_client.delete.assert_not_called()
+
+
+def test_absent_check_mode_nonexistent_key(capfd, fake_etcd3):
+    """state=absent in check mode with missing key: no change, no delete."""
+    mock_client = make_client(fake_etcd3, existing_value=None)
+
+    with pytest.raises(SystemExit), set_module_args(dict(BASE_ARGS, state="absent", _ansible_check_mode=True)):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["changed"] is False
+    mock_client.delete.assert_not_called()
+
+
+# ---------------------------------------------------------------------------
+# error paths
+# ---------------------------------------------------------------------------
+
+
+def test_connection_failure(capfd, fake_etcd3):
+    """Connection to etcd cluster fails: module should fail."""
+    fake_etcd3.client.side_effect = Exception("connection refused")
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["failed"] is True
+    assert "Cannot connect to etcd cluster" in result["msg"]
+
+
+def test_get_failure(capfd, fake_etcd3):
+    """etcd.get() raises: module should fail."""
+    mock_client = MagicMock()
+    mock_client.get.side_effect = Exception("read timeout")
+    fake_etcd3.client.return_value = mock_client
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["failed"] is True
+    assert "Cannot reach data" in result["msg"]
+
+
+def test_missing_library(capfd, mocker):
+    """etcd3 library not installed: module should fail."""
+    mocker.patch.object(etcd3_module, "HAS_ETCD", False)
+
+    with pytest.raises(SystemExit), set_module_args(BASE_ARGS):
+        etcd3_module.main()
+
+    out, dummy = capfd.readouterr()
+    result = json.loads(out)
+    assert result["failed"] is True