Allow default env to be set by env var (#267)

Author: pblowey

HISTORY.rst

@@ -7,6 +7,7 @@ Unreleased
 - Minimum supported python is now 3.11.
 - Switch python packaging backend back to setuptools. (`#263 <https://github.com/DiamondLightSource/python-zocalo/pull/263>`_)
 - ``zocalo.dlq_purge``: Show which queues DLQ messages came from, and accept queue names with prefix. (`#264 <https://github.com/DiamondLightSource/python-zocalo/pull/264>`_)
+- Allow default zocalo environment to be set by environment variable `ZOCALO_DEFAULT_ENV`. This takes priority over default in `ZOCALO_CONFIG` file (`#267 <https://github.com/DiamondLightSource/python-zocalo/pull/267>`_)  
 
 1.2.0 (2024-11-14)
 ------------------

src/zocalo/configuration/__init__.py

@@ -169,8 +169,11 @@ def activate(
             envs = zocalo.configuration.argparse.get_specified_environments(
                 arguments=self.environment_cmd_args
             )
-        if default and not envs and "default" in self._environments:
-            envs = ["default"]
+        if default and not envs:
+            if os.environ.get("ZOCALO_DEFAULT_ENV"):
+                envs = [os.environ["ZOCALO_DEFAULT_ENV"]]
+            elif "default" in self._environments:
+                envs = ["default"]
         for environment in envs:
             self.activate_environment(environment)
         return tuple(envs)

tests/configuration/test_configuration.py

@@ -215,14 +215,22 @@ def test_activate_additional_environments():
     assert "part-2" in str(zc)
 
 
-def test_activate_default_environment():
+def test_activate_default_environment_from_config_file():
     zc = zocalo.configuration.from_string(sample_configuration)
     e = zc.activate([])
     assert e == ("default",)
     assert zc.active_environments == ("default",)
     assert "default" in str(zc)
 
 
+def test_activate_default_environment_from_environment_variable():
+    with mock.patch.dict(os.environ, {"ZOCALO_DEFAULT_ENV": "partial"}):
+        zc = zocalo.configuration.from_string(sample_configuration)
+        e = zc.activate([])
+        assert e == ("partial",)
+        assert zc.active_environments == ("partial",)
+
+
 def test_activate_call_honours_default_flag():
     zc = zocalo.configuration.from_string(sample_configuration)
     e = zc.activate([], default=False)