Lazily load podman executable

.github/workflows/tox.yml

@@ -27,19 +27,19 @@ jobs:
           - tox_env: lint
           # - tox_env: docs
           - tox_env: py36-ansible29
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py36-ansible210
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py36-ansible211
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py37-ansible211
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py38-ansible211
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py39-ansible211
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: py39-devel-ansible211
-            PREFIX: PYTEST_REQPASS=4
+            PREFIX: PYTEST_REQPASS=5
           - tox_env: packaging
 
     steps:

src/molecule_podman/driver.py

@@ -161,10 +161,17 @@ def __init__(self, config=None):
         # MOLECULE_PODMAN_EXECUTABLE
         # An example could be MOLECULE_PODMAN_EXECUTABLE=podman-remote
         self.podman_exec = os.environ.get("MOLECULE_PODMAN_EXECUTABLE", "podman")
-        self.podman_cmd = distutils.spawn.find_executable(self.podman_exec)
-        if not self.podman_cmd:
-            msg = f"command not found in PATH {self.podman_exec}"
-            util.sysexit_with_message(msg)
+        self._podman_cmd = None
+
+    @property
+    def podman_cmd(self):
+        """Lazily calculate the podman command."""
+        if not self._podman_cmd:
+            self._podman_cmd = distutils.spawn.find_executable(self.podman_exec)
+            if not self._podman_cmd:
+                msg = f"command not found in PATH {self.podman_exec}"
+                util.sysexit_with_message(msg)
+        return self._podman_cmd
 
     @property
     def name(self):

src/molecule_podman/test/test_driver.py

@@ -1,7 +1,15 @@
 """Unit tests."""
 from molecule import api
 
+from molecule_podman.driver import Podman
+
 
 def test_driver_is_detected():
     """Asserts that molecule recognizes the driver."""
     assert any(str(d) == "podman" for d in api.drivers())
+
+
+def test_driver_initializes_without_podman_executable(monkeypatch):
+    """Make sure we can initiaize driver without having an executable present."""
+    monkeypatch.setenv("MOLECULE_PODMAN_EXECUTABLE", "bad-executable")
+    Podman()