Add a way to remove dashes in default network names

This is the behavior exhibited by docker compose. The network names are
user-visible through external networks, so previously anyone who
migrated from docker-compose needed to change their configuration. Now
it is possible to select compatibility via a flag in x-podman global
dictionary.

Signed-off-by: Povilas Kanapickas <povilas@radix.lt>

docs/Extensions.md

@@ -91,6 +91,23 @@ The options to the network modes are passed to the `--network` option of the `po
 as-is.
 
 
+## Compatibility of default network names between docker-compose and podman-compose
+
+Current versions of podman-compose may produce different default external network names than
+docker-compose under certain conditions. Specifically, docker-compose removes dashes (`-` character)
+from project name.
+
+To enable compatibility between docker-compose and podman-compose, specify
+`default_net_name_compat: true` under global `x-podman` key:
+
+```
+x-podman:
+    default_net_name_compat: true
+```
+
+By default `default_net_name_compat` is `false`. This will change to `true` at some point and the
+setting will be removed.
+
 ## Custom pods management
 
 Podman-compose can have containers in pods. This can be controlled by extension key x-podman in_pod.

newsfragments/default_net_name_compat.feature

@@ -0,0 +1 @@
+Added a way to get compatibility of default network names with docker compose. This is selected by setting `default_net_name_compat: true` on `x-podman` global dictionary.

podman_compose.py

@@ -336,9 +336,14 @@ def norm_ulimit(inner_value):
     return inner_value
 
 
-def default_network_name_for_project(proj_name, net, is_ext):
-    # docker-compose removes dashes from project name when building network name
-    return net if is_ext else f"{proj_name}_{net}"
+def default_network_name_for_project(compose, proj_name, net, is_ext):
+    if is_ext:
+        return net
+
+    default_net_name_compat = compose.x_podman.get("default_net_name_compat", False)
+    if default_net_name_compat is True:
+        return f"{proj_name.replace('-', '')}_{net}"
+    return f"{proj_name}_{net}"
 
 
 # def tr_identity(project_name, given_containers):
@@ -850,7 +855,7 @@ async def assert_cnt_nets(compose, cnt):
         net_desc = nets[net] or {}
         is_ext = net_desc.get("external", None)
         ext_desc = is_ext if is_dict(is_ext) else {}
-        default_net_name = default_network_name_for_project(proj_name, net, is_ext)
+        default_net_name = default_network_name_for_project(compose, proj_name, net, is_ext)
         net_name = ext_desc.get("name", None) or net_desc.get("name", None) or default_net_name
         try:
             await compose.podman.output([], "network", ["exists", net_name])
@@ -939,7 +944,7 @@ def get_net_args(compose, cnt):
         net_desc = nets[net] or {}
         is_ext = net_desc.get("external", None)
         ext_desc = is_ext if is_dict(is_ext) else {}
-        default_net_name = default_network_name_for_project(proj_name, net, is_ext)
+        default_net_name = default_network_name_for_project(compose, proj_name, net, is_ext)
         net_name = ext_desc.get("name", None) or net_desc.get("name", None) or default_net_name
         net_names.append(net_name)
     net_names_str = ",".join(net_names)
@@ -975,7 +980,7 @@ def get_net_args(compose, cnt):
             net_desc = nets[net_] or {}
             is_ext = net_desc.get("external", None)
             ext_desc = is_ext if is_dict(is_ext) else {}
-            default_net_name = default_network_name_for_project(proj_name, net_, is_ext)
+            default_net_name = default_network_name_for_project(compose, proj_name, net_, is_ext)
             net_name = ext_desc.get("name", None) or net_desc.get("name", None) or default_net_name
 
             ipv4 = net_config_.get("ipv4_address", None)
@@ -1677,6 +1682,7 @@ class PodmanCompose:
         self.services = None
         self.all_services = set()
         self.prefer_volume_over_mount = True
+        self.x_podman = {}
         self.merged_yaml = None
         self.yaml_hash = ""
         self.console_colors = [
@@ -1745,15 +1751,9 @@ class PodmanCompose:
         if isinstance(retcode, int):
             sys.exit(retcode)
 
-    def resolve_in_pod(self, compose):
+    def resolve_in_pod(self):
         if self.global_args.in_pod_bool is None:
-            extension_dict = compose.get("x-podman", None)
-            if extension_dict is not None:
-                in_pod_value = extension_dict.get("in_pod", None)
-                if in_pod_value is not None:
-                    self.global_args.in_pod_bool = in_pod_value
-            else:
-                self.global_args.in_pod_bool = True
+            self.global_args.in_pod_bool = self.x_podman.get("in_pod", True)
         # otherwise use `in_pod` value provided by command line
         return self.global_args.in_pod_bool
 
@@ -1994,7 +1994,9 @@ class PodmanCompose:
         given_containers.sort(key=lambda c: len(c.get("_deps", None) or []))
         # log("sorted:", [c["name"] for c in given_containers])
 
-        args.in_pod_bool = self.resolve_in_pod(compose)
+        self.x_podman = compose.get("x-podman", {})
+
+        args.in_pod_bool = self.resolve_in_pod()
         pods, containers = transform(args, project_name, given_containers)
         self.pods = pods
         self.containers = containers

tests/unit/test_container_to_args.py

@@ -17,6 +17,12 @@ def create_compose_mock(project_name="test_project_name"):
     compose.prefer_volume_over_mount = False
     compose.default_net = None
     compose.networks = {}
+    compose.x_podman = {}
+
+    async def podman_output(*args, **kwargs):
+        pass
+
+    compose.podman.output = mock.Mock(side_effect=podman_output)
     return compose
 
 
@@ -561,3 +567,28 @@ class TestContainerToArgs(unittest.IsolatedAsyncioTestCase):
                 "busybox",
             ],
         )
+
+    @parameterized.expand([
+        ("not_compat", False, "test_project_name", "test_project_name_network1"),
+        ("compat_no_dash", True, "test_project_name", "test_project_name_network1"),
+        ("compat_dash", True, "test_project-name", "test_projectname_network1"),
+    ])
+    async def test_network_default_name(self, name, is_compat, project_name, expected_network_name):
+        c = create_compose_mock(project_name)
+        c.x_podman = {"default_net_name_compat": is_compat}
+        c.networks = {'network1': {}}
+
+        cnt = get_minimal_container()
+        cnt['networks'] = ['network1']
+
+        args = await container_to_args(c, cnt)
+        self.assertEqual(
+            args,
+            [
+                "--name=project_name_service_name1",
+                "-d",
+                f"--network={expected_network_name}",
+                "--network-alias=service_name",
+                "busybox",
+            ],
+        )