matrixsynapse: Completely uninstall app

Remove database, mediafiles and freedombox configs.
Removal of certs are not neccessary since the next setup will
overwrite them

Test:
1. Install the app and set a domain
2. Reinstall the app and confirm the domain can be set like it's the first time

Signed-off-by: nbenedek <contact@nbenedek.me>
[sunil: Update docstrings, make uninstall fail-safe]
[sunil: Fix uninstall functional test]
Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: Sunil Mohan Adapa <sunil@medhas.org>

plinth/modules/matrixsynapse/__init__.py

@@ -126,6 +126,11 @@ class MatrixSynapseApp(app_module.App):
         config = self.get_component('turn-matrixsynapse').get_configuration()
         update_turn_configuration(config, force=True)
 
+    def uninstall(self):
+        """De-configure and uninstall the app."""
+        super().uninstall()
+        privileged.uninstall()
+
 
 class MatrixSynapseTurnConsumer(TurnConsumer):
     """Component to manage Coturn configuration for Matrix Synapse."""

plinth/modules/matrixsynapse/privileged.py

@@ -339,3 +339,10 @@ def _generate_mac(shared_secret: str, nonce: str, user: str, password: str,
         mac.update(user_type.encode('utf8'))
 
     return mac.hexdigest()
+
+
+@privileged
+def uninstall():
+    """Delete configuration and data directories."""
+    for item in ['/etc/matrix-synapse/conf.d', '/var/lib/matrix-synapse']:
+        shutil.rmtree(item, ignore_errors=True)

plinth/modules/matrixsynapse/tests/test_functional.py

@@ -24,3 +24,9 @@ class TestMatrixSynapseApp(functional.BaseAppTests):
         functional.install(session_browser, self.app_name)
         functional.app_select_domain_name(session_browser, self.app_name,
                                           'mydomain.example')
+
+    def test_uninstall(self, session_browser):
+        """After uninstall test, after installing select the domain again."""
+        super().test_uninstall(session_browser)
+        functional.app_select_domain_name(session_browser, self.app_name,
+                                          'mydomain.example')