Merge pull request #76 from chisou/feature/auto-application-key

Application key is automatically read from environment.

Author: chsou

CHANGELOG.md

@@ -1,5 +1,7 @@
 # Changelog
 
+* Single and multi tenant applications now automatically set the `application_key` property from the standard
+  `APPLICATION_KEY` environment variable. 
 * Added `get_count` function to `Operations` API.
 * Added `as_values` parameter to `get_all` and `select` functions of the Inventory, DeviceInventory,
   DeviceGroupInventory, Events, Alarms, Users, Operations, and AuditRecords API.

c8y_api/app/__init__.py

@@ -144,7 +144,8 @@ def __init__(
 
         Args:
             application_key (str|None): An application key to include in
-                all requests for tracking purposes.
+                all requests for tracking purposes; this will be read from
+                the environment (APPLICATION_KEY) if not defined.
             processing_mode (str);  Connection processing mode (see also
                 https://cumulocity.com/api/core/#processing-mode)
             cache_size (int|None): The maximum number of cached user
@@ -165,6 +166,8 @@ def __init__(
             username = self._get_env('C8Y_USER')
             password = self._get_env('C8Y_PASSWORD')
             auth = HTTPBasicAuth(f'{tenant_id}/{username}', password)
+        if not application_key:
+            application_key = self._get_env('APPLICATION_KEY')
         super().__init__(log=self._log, cache_size=cache_size, cache_ttl=cache_ttl,
                          base_url=baseurl, tenant_id=tenant_id, auth=auth,
                          application_key=application_key, processing_mode=processing_mode)
@@ -205,7 +208,8 @@ def __init__(self, application_key: str = None,  processing_mode: str = None,
 
         Args:
             application_key (str|None): An application key to include in
-                all requests for tracking purposes.
+                all requests for tracking purposes; this will be read from
+                the environment (APPLICATION_KEY) if not defined.
             processing_mode (str);  Connection processing mode (see also
                 https://cumulocity.com/api/core/#processing-mode)
             cache_size (int|None): The maximum number of cached tenant
@@ -217,13 +221,13 @@ def __init__(self, application_key: str = None,  processing_mode: str = None,
             A new MultiTenantCumulocityApp instance
         """
         super().__init__(log=self._log, cache_size=cache_size, cache_ttl=cache_ttl)
-        self.application_key = application_key
+        self.application_key = application_key or self._get_env('APPLICATION_KEY')
         self.processing_mode = processing_mode
         self.cache_size = cache_size
         self.cache_ttl = cache_ttl
         self.bootstrap_instance = self._create_bootstrap_instance(
-            application_key=application_key,
-            processing_mode=processing_mode,
+            application_key=self.application_key,
+            processing_mode=self.processing_mode,
         )
         self._subscribed_auths = TTLCache(maxsize=cache_size, ttl=cache_ttl)
         self._tenant_instances = TTLCache(maxsize=cache_size, ttl=cache_ttl)

tests/test_app.py

@@ -25,15 +25,16 @@
     'C8Y_BASEURL': 'http://baseurl',
     'C8Y_TENANT': 'tenant_id',
     'C8Y_USER': 'tenant_user',
-    'C8Y_PASSWORD': 'tenant_password'
+    'C8Y_PASSWORD': 'tenant_password',
+    'APPLICATION_KEY': 'application_key',
 }
 
 env_multi_tenant = {
     'C8Y_BASEURL': 'http://baseurl',
     'C8Y_BOOTSTRAP_TENANT': 'tenant_id',
     'C8Y_BOOTSTRAP_USER': 'tenant_user',
-    'C8Y_BOOTSTRAP_PASSWORD': 'tenant_password'
-
+    'C8Y_BOOTSTRAP_PASSWORD': 'tenant_password',
+    'APPLICATION_KEY': 'application_key',
 }
 
 
@@ -55,6 +56,7 @@ def test_per_tenant():
     assert c8y.username == env_per_tenant['C8Y_USER']
     assert isinstance(c8y.auth, HTTPBasicAuth)
     assert c8y.auth.password == env_per_tenant['C8Y_PASSWORD']
+    assert c8y.application_key == env_per_tenant['APPLICATION_KEY']
 
     # -> requests will be prepended with the base url
     with responses.RequestsMock() as rsps:
@@ -71,7 +73,6 @@ def test_per_tenant__user_instances():
     for single-tenant apps."""
 
     c8y = SimpleCumulocityApp(
-        application_key='app-key',
         processing_mode='proc-mode',
         cache_ttl=2,
     )
@@ -106,13 +107,29 @@ def test_per_tenant__user_instances():
     assert c8y_3 is not c8y_1
 
 
+@mock.patch.dict(os.environ, env_per_tenant, clear=True)
+def test_per_tenant_application_key():
+    """Verify that the application key from environment can be overwritten."""
+
+    # manually setting application
+    c8y = SimpleCumulocityApp(application_key='app_key')
+    # -> application key from environment overridden
+    assert c8y.application_key == 'app_key'
+
+    # create user instance from HTTP headers
+    headers = build_basic_auth('user', 'pass')
+    c8y_user = c8y.get_user_instance(headers)
+    # -> application key inherited
+    assert c8y_user.application_key == c8y.application_key
+
+
 @mock.patch.dict(os.environ, env_multi_tenant, clear=True)
 def test_multi_tenant__bootstrap_instance():
     """Verify that the bootstrap instance will be created properly within a
     multi-tenant environment."""
 
     c8y = MultiTenantCumulocityApp(
-        application_key='app-key',
+        # application_key='app-key',
         processing_mode='proc-mode',
     ).bootstrap_instance
 
@@ -121,8 +138,8 @@ def test_multi_tenant__bootstrap_instance():
     assert c8y.username == env_multi_tenant['C8Y_BOOTSTRAP_USER']
     assert isinstance(c8y.auth, HTTPBasicAuth)
     assert c8y.auth.password == env_multi_tenant['C8Y_BOOTSTRAP_PASSWORD']
+    assert c8y.application_key == env_multi_tenant['APPLICATION_KEY']
     # -> properties are inherited
-    assert c8y.application_key == 'app-key'
     assert c8y.processing_mode == 'proc-mode'
 
     # -> requests will be prepended with the base url
@@ -248,6 +265,7 @@ def test_multi_tenant__build_from_subscriptions():
         assert c8y.username == 'username'
         assert isinstance(c8y.auth, HTTPBasicAuth)
         assert c8y.auth.password == 'password'
+        assert c8y.application_key == c8y_factory.application_key
 
         # using the same tenant ID again
         read_subscriptions.reset_mock()
@@ -266,6 +284,30 @@ def test_multi_tenant__build_from_subscriptions():
         read_subscriptions.assert_not_called()
 
 
+@mock.patch.dict(os.environ, env_multi_tenant, clear=True)
+def test_multi_tenant__override_application_key():
+    """Verify that the application key from environment can be overwritten."""
+
+    # manually setting application
+    c8y = MultiTenantCumulocityApp(application_key='app_key')
+    # -> application key from environment overridden
+    assert c8y.application_key == 'app_key'
+
+    # create user instance from HTTP headers
+    headers = build_basic_auth('t12345/user', 'pass')
+    c8y_user = c8y.get_user_instance(headers)
+    # -> application key inherited
+    assert c8y_user.application_key == c8y.application_key
+
+    # create tenant instance
+    with patch.object(MultiTenantCumulocityApp, '_read_subscription_auths') as read_subscriptions:
+        # we mock _read_subscriptions so that we don't need an actual
+        # connection and have a proper return value
+        read_subscriptions.return_value = {'t12345': HTTPBasicAuth('username', 'password')}
+        c8y_tenant = c8y.get_tenant_instance('t12345')
+        assert c8y_tenant.application_key == c8y.application_key
+
+
 @mock.patch.dict(os.environ, env_multi_tenant, clear=True)
 def test_read_subscriptions():
     """Verify that the subscriptions are read and parsed properly."""