Base Attachment Object Store

Configuration

The configuration is done through the creation of a filesytem storage record into odoo. To create a new storage, go to the menu Settings > Technical > FS Storage and click on Create.

In addition to the common fields available to configure a storage, specifics fields are available under the section 'Attachment' to configure the way attachments will be stored in the filesystem.

• Optimizes Directory Path: This option is useful if you need to prevent having too many files in a single directory. It will create a directory structure based on the attachment's checksum (with 2 levels of depth) For example, if the checksum is 123456789, the file will be stored in the directory /path/to/storage/12/34/my_file-1-0.txt.
• Autovacuum GC: This is used to automatically remove files from the filesystem when it's no longer referenced in Odoo. Some storage backends (like S3) may charge you for the storage of files, so it's important to remove them when they're no longer needed. In some cases, this option is not desirable, for example if you're using a storage backend to store images shared with others systems (like your website) and you don't want to remove the files from the storage while they're still referenced into the others systems. This mechanism is based on a fs.file.gc model used to collect the files to remove. This model is automatically populated by the ir.attachment model when a file is removed from the database. If you disable this option, you'll have to manually take care of the records in the fs.file.gc for your filesystem storage.
• Use As Default For Attachment: This options allows you to declare the storage as the default one for attachments. If you have multiple filesystem storage configured, you can choose which one will be used by default for attachments. Once activated, attachments created without specifying a storage will be stored in this default storage.
• Force DB For Default Attachment Rules: This option is useful if you want to force the storage of some attachments in the database, even if you have a default filesystem storage configured. This is specially useful when you're using a storage backend like S3, where the latency of the network can be high. This option is a JSON field that allows you to define the mimetypes and the size limit below which the attachments will be stored in the database. Small images (128, 256) are used in Odoo in list / kanban views. We want them to be fast to read. They are generally \< 50KB (default configuration) so they don't take that much space in database, but they'll be read much faster than from the object storage. The assets (application/javascript, text/css) are stored in database as well whatever their size is:
• a database doesn't have thousands of them
• of course better for performance
• better portability of a database: when replicating a production instance for dev, the assets are included The default configuration is: > {"image/": 51200, "application/javascript": 0, "text/css": 0} > > Where the key is the beginning of the mimetype to configure and the > value is the limit in size below which attachments are kept in DB. 0 > means no limit. Default configuration means:
• images mimetypes (image/png, image/jpeg, ...) below 50KB are stored in database
• application/javascript are stored in database whatever their size
• text/css are stored in database whatever their size This option is only available on the filesystem storage that is used as default for attachments.

It is also possible to use different FS storages for attachments linked to different resource fields/models. You can configure it either on the fs.storage directly, or in a server environment file:

• From the fs.storage: Fields model_ids and field_ids will encode for which models/fields use this storage as default storage for attachments having these resource model/field. Note that if an attachment has both resource model and field, it will first take the FS storage where the field is explicitely linked, then is not found, the one where the model is explicitely linked.
• From a server environment file: In this case you just have to provide a comma-separated list of models (under the model_xmlids key) or fields (under the field_xmlids key). To do so, use the model/field XML ids provided by Odoo. See the Server Environment section for a concrete example.

Another key feature of this module is the ability to get access to the attachments from URLs.

• Base URL: This is the base URL used to access the attachments from the filesystem storage itself. If your storage doesn't provide a way to access the files from a URL, you can leave this field empty.
• Is Directory Path In URL: Normally the directory patch configured on the storage is not included in the URL. If you want to include it, you can activate this option.
• Use X-Sendfile To Serve Internal Url: If checked and odoo is behind a proxy that supports x-sendfile, the content served by the attachment's internal URL will be served by the proxy using the filesystem url path if defined (This field is available on the attachment if the storage is configured with a base URL) If not, the file will be served by odoo that will stream the content read from the filesystem storage. This option is useful to avoid to serve files from odoo and therefore to avoid to load the odoo process. To be fully functional, this option requires the proxy to support x-sendfile (apache) or x-accel-redirect (nginx). You must also configure your proxy by adding for each storage a rule to redirect the url rooted at the 'storagge code' to the server serving the files. For example, if you have a storage with the code 'my_storage' and a server serving the files at the url '', you must add the following rule in your proxy configuration:

location /my_storage/ {
    internal;
    proxy_pass http://myserver.com;
}

With this configuration a call to '/web/content/\/\\" for a file stored in the 'my_storage' storage will generate a response by odoo with the URI /my_storage/<paht_in_storage>/<att.name>-<att.id>-<version><att.extension> in the headers X-Accel-Redirect and X-Sendfile and the proxy will redirect to http://myserver.com/<paht_in_storage>/<att.name>-<att.id>-<version><att.extension>.

see

for more information.

• Use Filename Obfuscation: If checked, the filename used to store the content into the filesystem storage will be obfuscated. This is useful to avoid to expose the real filename of the attachments outside of the Odoo database. The filename will be obfuscated by using the checksum of the content. This option is to avoid when the content of your filestore is shared with other systems (like your website) and you want to keep a meaningful filename to ensure SEO. This option is disabled by default.

Server Environment

When you configure a storage through the use of server environment file, you can provide values for the following keys:

• optimizes_directory_path
• autovacuum_gc
• base_url
• is_directory_path_in_url
• use_x_sendfile_to_serve_internal_url
• use_as_default_for_attachments
• force_db_for_default_attachment_rules
• use_filename_obfuscation
• model_xmlids
• field_xmlids

For example, the configuration of my storage with code fsprod used to store the attachments by default could be:

[fs_storage.fsprod]
protocol=s3
options={"endpoint_url": "https://my_s3_server/", "key": "KEY", "secret": "SECRET"}
directory_path=my_bucket
use_as_default_for_attachments=True
use_filename_obfuscation=True
model_xmlids=base.model_res_lang,base.model_res_country
field_xmlids=base.field_res_partner__image_128

Advanced usage: Using attachment as a file

The open method on the attachment can be used to open manipulate the attachment as a file object. The object returned by the call to the method implements methods from io.IOBase. The method can ba called as any other python method. In such a case, it's your responsibility to close the file at the end of your process.

attachment = self.env.create({"name": "test.txt"})
the_file = attachment.open("wb")
try:
  the_file.write(b"content")
finally:
  the_file.close()

The result of the call to open also works in a context with block. In such a case, when the code exit the block, the file is automatically closed.

attachment = self.env.create({"name": "test.txt"})
with attachment.open("wb") as the_file:
  the_file.write(b"content")

It's always safer to prefer the second approach.

When your attachment is stored into the odoo filestore or into an external filesystem storage, each time you call the open method, a new file is created. This way of doing ensures that if the transaction is rolled back the original content is preserved. Nevertheless you could have use cases where you would like to write to the existing file directly. For example you could create an empty attachment to store a csv report and then use the open method to write your content directly into the new file. To support this kind a use cases, the parameter new_version can be passed as False to avoid the creation of a new file.

attachment = self.env.create({"name": "test.txt"})
with attachment.open("w", new_version=False) as f:
    writer = csv.writer(f, delimiter=";")
    ....

Tips & Tricks

• When working in multi staging environments, the management of the attachments can be tricky. For example, if you have a production instance and a staging instance based on a backup of the production environment, you may want to have the attachments shared between the two instances BUT you don't want to have one instance removing or modifying the attachments of the other instance. To do so, you can add on your staging instances a new storage and declare it as the default storage to use for attachments. This way, all the new attachments will be stored in this new storage but the attachments created on the production instance will still be read from the production storage. Be careful to adapt the configuration of your storage to the production environment to make it read only. (The use of server environment files is a good way to do so).
• When enabling Use As Default For Attachment you must be aware that this option applies from the point when the fs_attachment has been loaded by Odoo. This means that some attachments (such as icons) created during the update of modules that are loaded before fs_attachment will still be stored in the location defined in the ir_attachment.location system parameter (which is file by default, meaning the regular on-disk filestore directory). A simple way to work around this issue is to set the ir_attachment.location System Parameter record to db.