feat: support nested defaults

podman_compose.py

@@ -260,8 +260,8 @@ def fix_mount_dict(
         (?:{
             (?P<braced>[_a-zA-Z][_a-zA-Z0-9]*)
             (?:(?P<empty>:)?(?:
-                (?:-(?P<default>[^}]*)) |
-                (?:\?(?P<err>[^}]*))
+                (?:-(?P<default>.*)) |
+                (?:\?(?P<err>.*))
             ))?
         })
     )
@@ -305,8 +305,8 @@ def convert(m: re.Match) -> str:
             if value is not None:
                 return str(value)
             if m.group("err") is not None:
-                raise RuntimeError(m.group("err"))
-            return m.group("default") or ""
+                raise RuntimeError(rec_subs(m.group("err"), subs_dict))
+            return rec_subs(m.group("default") or "", subs_dict)
 
         value = var_re.sub(convert, value)
     elif hasattr(value, "__iter__"):

tests/integration/interpolation/.env

@@ -1,2 +1,3 @@
 DOT_ENV_VARIABLE=This value is from the .env file
 TEST_LABELS=TEST
+DOT_ENV_VARIABLE_INTERPOLATION=Dotenv with default ${DEFAULT}

tests/integration/interpolation/docker-compose-nested.yml

@@ -0,0 +1,19 @@
+version: "3.7"
+services:
+    variables:
+        image: busybox
+        command: ["/bin/busybox", "sh", "-c", "export | grep EXAMPLE"]
+        environment:
+            EXAMPLE_COLON_DASH_DEFAULT_WITH_INTERPOLATION: ${EMPTY:-My default is ${DEFAULT}}
+            EXAMPLE_DASH_DEFAULT_WITH_INTERPOLATION: ${NOT_SET-My default is ${DEFAULT}}
+            EXAMPLE_DOTENV_INTERPOLATION: ${DOT_ENV_VARIABLE_INTERPOLATION}
+    labels_test:
+        image: busybox
+        labels:
+            - "${EMPTY:-empty_${TEST_LABELS}}=test_labels"
+            - "${NOT_SET-notset_${TEST_LABELS}}=test_labels"
+            - test.${EMPTY:-empty_${TEST_LABELS}}=${EMPTY:-empty_${TEST_LABELS}}
+            - test.${NOT_SET-notset_${TEST_LABELS}}=${NOT_SET-notset_${TEST_LABELS}}
+            - "${EMPTY:-empty_${TEST_LABELS}}.test2=test2(`${EMPTY:-empty_${TEST_LABELS}}`)"
+            - "${NOT_SET-notset_${TEST_LABELS}}.test2=test2(`${NOT_SET-notset_${TEST_LABELS}}`)"
+

tests/integration/interpolation/test_podman_compose_interpolation.py

@@ -9,8 +9,8 @@
 from tests.integration.test_utils import test_path
 
 
-def compose_yaml_path() -> str:
-    return os.path.join(os.path.join(test_path(), "interpolation"), "docker-compose.yml")
+def compose_yaml_path(file: str) -> str:
+    return os.path.join(os.path.join(test_path(), "interpolation"), file)
 
 
 class TestComposeInterpolation(unittest.TestCase, RunSubprocessMixin):
@@ -21,13 +21,13 @@ def test_interpolation(self) -> None:
                 "EXAMPLE_VARIABLE_USER=test_user",
                 podman_compose_path(),
                 "-f",
-                compose_yaml_path(),
+                compose_yaml_path("docker-compose.yml"),
                 "up",
             ])
             output, _ = self.run_subprocess_assert_returncode([
                 podman_compose_path(),
                 "-f",
-                compose_yaml_path(),
+                compose_yaml_path("docker-compose.yml"),
                 "logs",
             ])
             self.assertIn("EXAMPLE_VARIABLE='Host user: test_user'", str(output))
@@ -53,6 +53,53 @@ def test_interpolation(self) -> None:
             self.run_subprocess_assert_returncode([
                 podman_compose_path(),
                 "-f",
-                compose_yaml_path(),
+                compose_yaml_path("docker-compose.yml"),
+                "down",
+            ])
+
+    def test_nested_interpolation(self) -> None:
+        try:
+            self.run_subprocess_assert_returncode([
+                "env",
+                "DEFAULT=nested",
+                "TEST_LABELS=foo",
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path("docker-compose-nested.yml"),
+                "up",
+            ])
+            output, _ = self.run_subprocess_assert_returncode([
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path("docker-compose-nested.yml"),
+                "logs",
+            ])
+            self.assertIn(
+                "EXAMPLE_COLON_DASH_DEFAULT_WITH_INTERPOLATION='My default is nested'", str(output)
+            )
+            self.assertIn(
+                "EXAMPLE_DASH_DEFAULT_WITH_INTERPOLATION='My default is nested'", str(output)
+            )
+            self.assertIn("EXAMPLE_DOTENV_INTERPOLATION='Dotenv with default nested'", str(output))
+
+            output, _ = self.run_subprocess_assert_returncode([
+                "podman",
+                "inspect",
+                "interpolation_labels_test_1",
+            ])
+            inspect_output = json.loads(output)
+            labels_dict = inspect_output[0].get("Config", {}).get("Labels", {})
+            self.assertIn(('empty_foo', 'test_labels'), labels_dict.items())
+            self.assertIn(('notset_foo', 'test_labels'), labels_dict.items())
+            self.assertIn(('test.empty_foo', 'empty_foo'), labels_dict.items())
+            self.assertIn(('test.notset_foo', 'notset_foo'), labels_dict.items())
+            self.assertIn(('empty_foo.test2', 'test2(`empty_foo`)'), labels_dict.items())
+            self.assertIn(('notset_foo.test2', 'test2(`notset_foo`)'), labels_dict.items())
+
+        finally:
+            self.run_subprocess_assert_returncode([
+                podman_compose_path(),
+                "-f",
+                compose_yaml_path("docker-compose-nested.yml"),
                 "down",
             ])