fix: do not create networks and volumes with --dry-run

newsfragments/dry_run_no_network_volume_creation.bugfix

@@ -0,0 +1 @@
+Fixed ``--dry-run`` creating networks and volumes: ``podman-compose --dry-run up`` now only logs the ``network create``/``volume create`` commands instead of running them.

podman_compose.py

@@ -631,6 +631,9 @@ async def assert_volume(compose: PodmanCompose, mount_dict: dict[str, Any]) -> N
         for opt, value in driver_opts.items():
             args.extend(["--opt", f"{opt}={value}"])
         args.append(vol_name)
+        if compose.podman.dry_run:
+            log.info("%s volume %s", compose.podman.podman_path, " ".join(args))
+            return
         await compose.podman.output([], "volume", args)
         await compose.podman.output([], "volume", ["inspect", vol_name])
 
@@ -1187,6 +1190,9 @@ async def assert_cnt_nets(compose: PodmanCompose, cnt: dict[str, Any]) -> None:
                     f"Create it first with: podman network create '{net_name}'"
                 ) from e
             args = get_network_create_args(net_desc, compose.project_name, net_name)
+            if compose.podman.dry_run:
+                log.info("%s network %s", compose.podman.podman_path, " ".join(args))
+                continue
             await compose.podman.output([], "network", args)
             await compose.podman.output([], "network", ["exists", net_name])
 

tests/unit/test_dry_run.py

@@ -0,0 +1,65 @@
+# SPDX-License-Identifier: GPL-2.0
+import asyncio
+import subprocess
+from unittest import IsolatedAsyncioTestCase
+from unittest import mock
+
+from podman_compose import Podman
+from podman_compose import PodmanCompose
+from podman_compose import assert_cnt_nets
+from podman_compose import assert_volume
+
+
+def get_dry_run_compose() -> mock.MagicMock:
+    compose = mock.MagicMock(spec=PodmanCompose)
+    compose.project_name = "test_project"
+    compose.get_podman_args.return_value = []
+    compose.podman = Podman(compose, "podman", True, asyncio.Semaphore(1))
+    return compose
+
+
+class TestDryRun(IsolatedAsyncioTestCase):
+    async def test_assert_volume_does_not_create_volume(self) -> None:
+        compose = get_dry_run_compose()
+        mount_dict = {
+            "type": "volume",
+            "source": "testvol",
+            "target": "/root",
+            "_vol": {"name": "test_project_testvol"},
+        }
+
+        with mock.patch.object(compose.podman, "output") as output:
+            output.side_effect = [
+                subprocess.CalledProcessError(1, "podman volume inspect"),
+                b"",
+                b"",
+            ]
+            await assert_volume(compose, mount_dict)
+
+        self.assertEqual(
+            [args for args, _ in output.call_args_list],
+            [([], "volume", ["inspect", "test_project_testvol"])],
+        )
+
+    async def test_assert_cnt_nets_does_not_create_network(self) -> None:
+        compose = get_dry_run_compose()
+        compose.networks = {"srv": {}}
+        compose.default_net = "srv"
+        cnt = {"service_name": "alpine", "networks": ["srv"]}
+
+        with mock.patch.object(compose.podman, "output") as output:
+            output.side_effect = [
+                subprocess.CalledProcessError(1, "podman network exists"),
+                b"",
+                b"",
+            ]
+            with mock.patch(
+                "podman_compose.default_network_name_for_project",
+                return_value="test_project_srv",
+            ):
+                await assert_cnt_nets(compose, cnt)
+
+        self.assertEqual(
+            [args for args, _ in output.call_args_list],
+            [([], "network", ["exists", "test_project_srv"])],
+        )