Object Storage - inactive mode

README.md

@@ -162,3 +162,8 @@ environment. It will refuse to start if anything is badly configured.
 
 The checks can be bypassed with the environment variable
 `ODOO_CLOUD_PLATFORM_UNSAFE` set to `1`.
+
+### Attachment storage inactivation 
+
+To prevent object storage to be accessed while failing for any kind of reason
+set this environment variable `ATTACHMENT_STORAGE_INACTIVE` set to `1`.

base_attachment_object_storage/README.rst

@@ -1,7 +1,7 @@
 Base class for attachments on external object store
 ===================================================
 
-This is a base addon that regroup common code used by addons targeting specific object store 
+This is a base addon that regroup common code used by addons targeting specific object store
 
 Configuration
 -------------
@@ -38,3 +38,9 @@ Default configuration means:
   stored in database
 * application/javascript are stored in database whatever their size
 * text/css are stored in database whatever their size
+
+Inactivate attachment storage I/O
+---------------------------------
+
+Define a environment variable `ATTACHMENT_STORAGE_INACTIVE` set to `1`
+This will prevent any kind of exceptions and read/write on storage attachments.

base_attachment_object_storage/models/ir_attachment.py

@@ -5,6 +5,7 @@ import inspect
 import logging
 import os
 import time
+from distutils.util import strtobool
 
 import psycopg2
 import odoo
@@ -18,6 +19,10 @@ from odoo.tools.safe_eval import const_eval
 _logger = logging.getLogger(__name__)
 
 
+def is_true(strval):
+    return bool(strtobool(strval or '0'))
+
+
 def clean_fs(files):
     _logger.info('cleaning old files from filestore')
     for full_path in files:
@@ -40,6 +45,18 @@ def clean_fs(files):
 class IrAttachment(models.Model):
     _inherit = 'ir.attachment'
 
+    @staticmethod
+    def is_storage_inactive(storage=None, log=True):
+        msg = _("Storages are inactive (see environment configuration).")
+        if storage:
+            msg = _(
+                "Storage '%s' is inactive (see environment configuration)."
+            ) % (storage,)
+        is_inactive = is_true(os.environ.get("ATTACHMENT_STORAGE_INACTIVE"))
+        if is_inactive and log:
+            _logger.warning(msg)
+        return is_inactive
+
     def _register_hook(self):
         super()._register_hook()
         location = self.env.context.get('storage_location') or self._storage()
@@ -151,6 +168,8 @@ class IrAttachment(models.Model):
         ``_store_in_db_instead_of_object_storage_domain``.
 
         """
+        if self.is_storage_inactive():
+            return True
         storage_config = self._get_storage_force_db_config()
         for mimetype_key, limit in storage_config.items():
             if mimetype.startswith(mimetype_key):
@@ -190,8 +209,9 @@ class IrAttachment(models.Model):
         )
 
     def _store_file_write(self, key, bin_data):
+        storage = self.storage()
         raise NotImplementedError(
-            'No implementation for %s' % (self.storage(),)
+            'No implementation for %s' % (storage,)
         )
 
     def _store_file_delete(self, fname):
@@ -229,6 +249,8 @@ class IrAttachment(models.Model):
     @api.model
     def _is_file_from_a_store(self, fname):
         for store_name in self._get_stores():
+            if self.is_storage_inactive(store_name):
+                continue
             uri = '{}://'.format(store_name)
             if fname.startswith(uri):
                 return True
@@ -263,6 +285,9 @@ class IrAttachment(models.Model):
         self.ensure_one()
         _logger.info('inspecting attachment %s (%d)', self.name, self.id)
         fname = self.store_fname
+        storage = fname.partition('://')[0]
+        if self.is_storage_inactive(storage):
+            fname = False
         if fname:
             # migrating from filesystem filestore
             # or from the old 'store_fname' without the bucket name
@@ -305,6 +330,8 @@ class IrAttachment(models.Model):
         It is not called anywhere, but can be called by RPC or scripts.
         """
         storage = self._storage()
+        if self.is_storage_inactive(storage):
+            return
         if storage not in self._get_stores():
             return
 
@@ -358,6 +385,8 @@ class IrAttachment(models.Model):
     def _force_storage_to_object_storage(self, new_cr=False):
         _logger.info('migrating files to the object storage')
         storage = self.env.context.get('storage_location') or self._storage()
+        if self.is_storage_inactive(storage):
+            return
         # The weird "res_field = False OR res_field != False" domain
         # is required! It's because of an override of _search in ir.attachment
         # which adds ('res_field', '=', False) when the domain does not