Support podman-specific per-network mac_address specifiation

Signed-off-by: Bas Zoetekouw <bas.zoetekouw@surf.nl>

docs/Extensions.md

@@ -0,0 +1,47 @@
+# Podman specific extensions to the docker-compose format
+
+Podman-compose supports the following extension to the docker-compose format.
+
+## Per-network MAC-addresses
+
+Generic docker-compose files support specification of the MAC address on the container level. If the
+container has multiple network interfaces, the specified MAC address is applied to the first
+specified network.
+
+Podman-compose in addition supports the specification of MAC addresses on a per-network basis. This
+is done by adding a `podman.mac_address` key to the network configuration in the container. The
+value of the `podman.mac_address` key is the MAC address to be used for the network interface.
+
+Specifying a MAC address for the container and for individual networks at the same time is not
+supported.
+
+Example:
+
+```yaml
+---
+version: "3"
+
+networks:
+  net0:
+    driver: "bridge"
+    ipam:
+      config:
+        - subnet: "192.168.0.0/24"
+  net1:
+    driver: "bridge"
+    ipam:
+      config:
+        - subnet: "192.168.1.0/24"
+
+services:
+  webserver
+    image: "busybox"
+    command: ["/bin/busybox", "httpd", "-f", "-h", "/etc", "-p", "8001"]
+    networks:
+      net0:
+        ipv4_address: "192.168.0.10"
+        podman.mac_address: "02:aa:aa:aa:aa:aa"
+      net1:
+        ipv4_address: "192.168.1.10"
+        podman.mac_address: "02:bb:bb:bb:bb:bb"
+```

podman_compose.py

@@ -779,10 +779,8 @@ async def assert_cnt_nets(compose, cnt):
 def get_net_args(compose, cnt):
     service_name = cnt["service_name"]
     net_args = []
-    mac_address = cnt.get("mac_address", None)
-    if mac_address:
-        net_args.extend(["--mac-address", mac_address])
     is_bridge = False
+    mac_address = cnt.get("mac_address", None)
     net = cnt.get("network_mode", None)
     if net:
         if net == "none":
@@ -866,6 +864,18 @@ def get_net_args(compose, cnt):
         else:
             multiple_nets = {net: net_config or {} for net, net_config in multiple_nets.items()}
 
+        # if a mac_address was specified on the container level, we need to check that it is not
+        # specified on the network level as well
+        if mac_address is not None:
+            for net_config_ in multiple_nets.values():
+                network_mac = net_config_.get("podman.mac_address", None)
+                if network_mac is not None:
+                    raise RuntimeError(
+                        f"conflicting mac addresses {mac_address} and {network_mac}:"
+                        "specifying mac_address on both container and network level "
+                        "is not supported"
+                    )
+
         for net_, net_config_ in multiple_nets.items():
             net_desc = nets[net_] or {}
             is_ext = net_desc.get("external", None)
@@ -875,6 +885,16 @@ def get_net_args(compose, cnt):
 
             ipv4 = net_config_.get("ipv4_address", None)
             ipv6 = net_config_.get("ipv6_address", None)
+            # custom extension; not supported by docker-compose v3
+            mac = net_config_.get("podman.mac_address", None)
+
+            # if a mac_address was specified on the container level, apply it to the first network
+            # This works for Python > 3.6, because dict insert ordering is preserved, so we are
+            # sure that the first network we encounter here is also the first one specified by
+            # the user
+            if mac is None and mac_address is not None:
+                mac = mac_address
+                mac_address = None
 
             net_options = []
             if ipv4:
@@ -893,6 +913,8 @@ def get_net_args(compose, cnt):
             net_args.append(f"--ip={ip}")
         if ip6:
             net_args.append(f"--ip6={ip6}")
+        if mac_address:
+            net_args.append(f"--mac-address={mac_address}")
 
     if is_bridge:
         net_args.extend(["--network-alias", ",".join(aliases)])

pytests/test_get_net_args.py

@@ -104,10 +104,27 @@ class TestGetNetArgs(unittest.TestCase):
         container["mac_address"] = mac
 
         expected_args = [
-            "--mac-address",
-            mac,
             "--network",
             f"{PROJECT_NAME}_net0",
+            "--mac-address=" + mac,
+            "--network-alias",
+            SERVICE_NAME,
+        ]
+        args = get_net_args(compose, container)
+        self.assertListEqual(expected_args, args)
+
+    def test_one_mac_two_nets(self):
+        mac = "00:11:22:33:44:55"
+        compose = get_networked_compose(num_networks=6)
+        container = get_minimal_container()
+        container["networks"] = {"net0": {}, "net1": {}}
+        container["mac_address"] = mac
+
+        expected_args = [
+            "--network",
+            f"{PROJECT_NAME}_net0:mac={mac}",
+            "--network",
+            f"{PROJECT_NAME}_net1",
             "--network-alias",
             SERVICE_NAME,
         ]
@@ -182,6 +199,49 @@ class TestGetNetArgs(unittest.TestCase):
         args = get_net_args(compose, container)
         self.assertListEqual(expected_args, args)
 
+    # custom extension; not supported by docker-compose
+    def test_two_mac(self):
+        mac0 = "00:00:00:00:00:01"
+        mac1 = "00:00:00:00:00:02"
+        compose = get_networked_compose(num_networks=2)
+        container = get_minimal_container()
+        container["networks"] = {
+            "net0": {"podman.mac_address": mac0},
+            "net1": {"podman.mac_address": mac1},
+        }
+
+        expected_args = [
+            "--network",
+            f"{PROJECT_NAME}_net0:mac={mac0}",
+            "--network",
+            f"{PROJECT_NAME}_net1:mac={mac1}",
+            "--network-alias",
+            SERVICE_NAME,
+        ]
+        args = get_net_args(compose, container)
+        self.assertListEqual(expected_args, args)
+
+    def test_mixed_mac(self):
+        ip4_0 = "192.168.0.42"
+        ip4_1 = "192.168.1.42"
+        ip4_2 = "192.168.2.42"
+        mac_0 = "00:00:00:00:00:01"
+        mac_1 = "00:00:00:00:00:02"
+
+        compose = get_networked_compose(num_networks=3)
+        container = get_minimal_container()
+        container["networks"] = {
+            "net0": {"ipv4_address": ip4_0},
+            "net1": {"ipv4_address": ip4_1, "podman.mac_address": mac_0},
+            "net2": {"ipv4_address": ip4_2},
+        }
+        container["mac_address"] = mac_1
+
+        expected_exception = (
+            r"specifying mac_address on both container and network level " r"is not supported"
+        )
+        self.assertRaisesRegex(RuntimeError, expected_exception, get_net_args, compose, container)
+
     def test_mixed_config(self):
         ip4_0 = "192.168.0.42"
         ip4_1 = "192.168.1.42"
@@ -199,10 +259,8 @@ class TestGetNetArgs(unittest.TestCase):
         container["mac_address"] = mac
 
         expected_args = [
-            "--mac-address",
-            mac,
             "--network",
-            f"{PROJECT_NAME}_net0:ip={ip4_0},ip={ip6_0}",
+            f"{PROJECT_NAME}_net0:ip={ip4_0},ip={ip6_0},mac={mac}",
             "--network",
             f"{PROJECT_NAME}_net1:ip={ip4_1}",
             "--network",

tests/nets_test_ip/docker-compose.yml

@@ -20,8 +20,10 @@ services:
         networks:
             shared-network:
                 ipv4_address: "172.19.1.10"
+                podman.mac_address: "02:01:01:00:01:01"
             internal-network:
                 ipv4_address: "172.19.2.10"
+                podman.mac_address: "02:01:01:00:02:01"
         volumes:
             - ./test1.txt:/var/www/html/index.txt:ro,z
     web2:

tests/test_podman_compose_networks.py

@@ -91,8 +91,11 @@ class TestPodmanComposeNetwork(RunSubprocessMixin, unittest.TestCase):
                 self.assertEqual(f"{expect}\r\n", out.decode('utf-8'))
 
         expected_macip = {
-            "web1": {"eth0": ["172.19.1.10"], "eth1": ["172.19.2.10"]},
-            "web2": {"eth0": ["172.19.2.11"]},
+            "web1": {
+                "eth0": ["172.19.1.10", "02:01:01:00:01:01"],
+                "eth1": ["172.19.2.10", "02:01:01:00:02:01"],
+            },
+            "web2": {"eth0": ["172.19.2.11", "02:01:01:00:02:02"]},
         }
 
         for service, interfaces in expected_macip.items():
@@ -108,5 +111,6 @@ class TestPodmanComposeNetwork(RunSubprocessMixin, unittest.TestCase):
             ]
             out, _ = self.run_subprocess_assert_returncode(ip_cmd)
             for interface, values in interfaces.items():
-                ip = values[0]
+                ip, mac = values
+                self.assertIn(f"ether {mac}", out.decode('utf-8'))
                 self.assertIn(f"inet {ip}/", out.decode('utf-8'))