Store the python version on startup in config (pymedusa#5892)

* Store the python (major) version on startup in config.
This can be used to check when a user starts medusa the next time with a different version.

* Replace dogpile cache, if we up/down the running python interpreter.

* Move the python check to start.py

* Update tmdb.py

revert

* * Moved the logic into the migrate_python_version function
* Removed the save_config, as we should depend on the saven on shutdown.
* store full semver version, instead of the major version.

* Forgot to remove this

* Small changes to make code more concise

* More specific message

SickBeard.py

@@ -1,9 +1,14 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # -*- coding: utf-8 -*
 """Script for backwards compatibility."""
 from __future__ import unicode_literals
 
+import sys
+
 from medusa.__main__ import main
 
 if __name__ == '__main__':
+    if sys.version_info.major == 3 and sys.version_info.minor < 5:
+        print('Medusa supports Python 2 from version 2.7.10 and Python 3 from version 3.5.0, exiting!')
+        raise Exception('Incorrect Python version. Shutting down!')
     main()

medusa/__main__.py

@@ -425,6 +425,7 @@ def initialize(self, console_logging=True):
             app.GIT_PASSWORD = check_setting_str(app.CFG, 'General', 'git_password', '', censor_log='low')
             app.GIT_TOKEN = check_setting_str(app.CFG, 'General', 'git_token', '', censor_log='low', encrypted=True)
             app.DEVELOPER = bool(check_setting_int(app.CFG, 'General', 'developer', 0))
+            app.PYTHON_VERSION = check_setting_list(app.CFG, 'General', 'python_version', [], transform=int)
 
             # debugging
             app.DEBUG = bool(check_setting_int(app.CFG, 'General', 'debug', 0))
@@ -1077,9 +1078,12 @@ def initialize(self, console_logging=True):
                 # Disable flag to erase cache
                 app.SUBTITLES_ERASE_CACHE = False
 
+            # Check if we start with a different Python version since last start
+            python_version_changed = self.migrate_python_version()
+
             # Check if we need to perform a restore of the cache folder
             Application.restore_cache_folder(app.CACHE_DIR)
-            cache.configure(app.CACHE_DIR)
+            cache.configure(app.CACHE_DIR, replace=python_version_changed)
 
             # Rebuild the censored list
             app_logger.rebuild_censored_list()
@@ -1247,6 +1251,27 @@ def path_leaf(path):
                 folder_path = os.path.join(cache_folder, name)
                 helpers.remove_folder(folder_path)
 
+    @staticmethod
+    def migrate_python_version():
+        """
+        Perform some cleanups in case we switch between major Python versions.
+
+        It's possible to switch from Python version 2 to 3 or vice versa.
+        In that case we might wanna run some sanity actions, to make sure everything keeps working.
+
+        :return: True if the major Python version has changed since last start
+        :return type: Boolean
+        """
+        # TODO: Leaving this here as a marking for when we merge the python3 changes.
+        current_version = app.PYTHON_VERSION
+        app.PYTHON_VERSION = list(sys.version_info)[:3]
+
+        # Run some sanitation when switching between Python versions
+        if current_version and current_version[0] != app.PYTHON_VERSION[0]:
+            return True
+
+        return False
+
     @staticmethod
     def start_threads():
         """Start application threads."""
@@ -1545,6 +1570,7 @@ def save_config():
         new_config['General']['calendar_icons'] = int(app.CALENDAR_ICONS)
         new_config['General']['no_restart'] = int(app.NO_RESTART)
         new_config['General']['developer'] = int(app.DEVELOPER)
+        new_config['General']['python_version'] = app.PYTHON_VERSION
         new_config['General']['display_all_seasons'] = int(app.DISPLAY_ALL_SEASONS)
         new_config['General']['news_last_read'] = app.NEWS_LAST_READ
         new_config['General']['broken_providers'] = helpers.get_broken_providers() or app.BROKEN_PROVIDERS

medusa/app.py

@@ -52,6 +52,7 @@ def __init__(self):
         # static configuration
         self.LOCALE = None, None
         self.OS_USER = None
+        self.PYTHON_VERSION = []
         self.OPENSSL_VERSION = None
         self.APP_VERSION = None
         self.MAJOR_DB_VERSION = None

medusa/cache.py

@@ -47,34 +47,34 @@ def release_write_lock(self):
 anidb_cache = make_region()
 
 
-def configure(cache_dir):
+def configure(cache_dir, replace=False):
     """Configure caches."""
     # memory cache
     from subliminal.cache import region as subliminal_cache
 
     memory_cache.configure('dogpile.cache.memory', expiration_time=timedelta(hours=1))
 
     # subliminal cache
-    subliminal_cache.configure('dogpile.cache.dbm',
+    subliminal_cache.configure('dogpile.cache.dbm', replace_existing_backend=replace,
                                expiration_time=timedelta(days=30),
                                arguments={
                                    'filename': os.path.join(cache_dir, 'subliminal.dbm'),
                                    'lock_factory': MutexLock})
 
     # application cache
-    cache.configure('dogpile.cache.dbm',
+    cache.configure('dogpile.cache.dbm', replace_existing_backend=replace,
                     expiration_time=timedelta(days=1),
                     arguments={'filename': os.path.join(cache_dir, 'application.dbm'),
                                'lock_factory': MutexLock})
 
     # recommended series cache
-    recommended_series_cache.configure('dogpile.cache.dbm',
+    recommended_series_cache.configure('dogpile.cache.dbm', replace_existing_backend=replace,
                                        expiration_time=timedelta(days=7),
                                        arguments={'filename': os.path.join(cache_dir, 'recommended.dbm'),
                                                   'lock_factory': MutexLock})
 
     # anidb (adba) series cache
-    anidb_cache.configure('dogpile.cache.dbm',
+    anidb_cache.configure('dogpile.cache.dbm', replace_existing_backend=replace,
                           expiration_time=timedelta(days=3),
                           arguments={'filename': os.path.join(cache_dir, 'anidb.dbm'),
                                      'lock_factory': MutexLock})

start.py

@@ -1,9 +1,14 @@
-#!/usr/bin/env python2.7
+#!/usr/bin/env python
 # -*- coding: utf-8 -*
 """Startup script."""
 from __future__ import unicode_literals
 
+import sys
+
 from medusa.__main__ import main
 
 if __name__ == '__main__':
+    if sys.version_info.major == 3 and sys.version_info.minor < 5:
+        print('Medusa supports Python 2 from version 2.7.10 and Python 3 from version 3.5.0, exiting!')
+        raise Exception('Incorrect Python version. Shutting down!')
     main()