File System Buckets

File System Buckets

When you deploy an application on Clever Cloud, like most PaaS, a new virtual machine is created, the previous one is deleted. If your application generates data, for example if you let users upload pictures and you do not store it on external services like S3, you will lose anything stored on the disk.

The Git deployment does not allow you to keep generated data files between deployments. To avoid the loss of your data, you have to mount a persistent filesystem. This is why we created File System Buckets.

You will be able to retrieve generated data between two deployments.

• Back-ups are not included in the public cloud offer. You can still do them manually.
• FSBuckets are not available for Docker applications because of security concerns.

Configuring your application

Buckets are configured using environment variables. Add the following to your application :


Don’t forget to replace the path of the mounted folder and the fs-bucket host with the targeted folder path (make sure the folder does not exists) and your fs-bucket host.

Optionnally, you can add :async to the end of the environment variable. This will make Clever Cloud mount the FS Bucket with the async option. It will make the FS Bucket faster (sometimes up to 3 times faster), but in case of a network issue it may cause file corruption.

You can setup multiple buckets by appending a number at the end of the environment variable’s name.


Note that the async parameter can be set per bucket.

Configuring your application with buckets.json (@deprecated)

This method is deprecated
This method is deprecated, we strongly recommend that you use environment variables. If you want to switch from this method to the environment variables, you need to remove the buckets.json file. Otherwise, the environment variables will be ignored. Also, this method does not support the async parameter.

To configure your application to use buckets, use the clevercloud/buckets.json file.
The clevercloud folder must be located at the root of your application.
The buckets.json file must contain the following structure:

    "bucket" : "bucketId",
    "folder" : "/myFolder",
    "apps"   : ["app_id"]

    "bucket_host" : "",
    "folder" : "/myotherFolder",
    "apps"   : ["app_id_2"]
You can find a pre-filled json object to copy in the dashboard of your FSBucket add-on, in the “Dashboard configuration” tab

It’s a json array containing objects with at least two fields:

RequiredbucketThe bucket id you can find in the console. It begins with bucket_. This is for “old-style” buckets (created before the 7 December 2015)
Requiredbucket_hostThe bucket host you can find in the console. It begins with bucket- and ends with This is for “new-style” buckets.
RequiredfolderThe folder you want the bucket to be mounted in. Should start with /. Using the example myFolder, you can access your bucket via the myFolder folder at the root of your application (which absolute path is available in the APP_HOME environment variable)
OptionalappsWhitelist of the applications allowed to mount this bucket. It’s helpful if you need to deploy a preprod app and a prod app using the exact same codebase but different buckets

The folder must not exist in your repository (or it needs to be empty). Otherwise, the mount of your bucket will be ignored. You can mount the same bucket in different folders, but they will share the same content, so it’s not the solution. You should prefer to mount the bucket in only one folder and then manage multiple subfolders in it.

You cannot mount two buckets in the same folder for the same app. If you put the same “folder” value for two entries in your environment variables or the buckets.json array, make sure that the “apps” fields make the two buckets mutually exclusive upon deployment!

Accessing your data inside the FS Bucket

From your application

Your bucket is mounted at the configured path, starting from your application’s root folder.

If you want to use an absolute path, you can use the APP_HOME environment variable, see special environment variables

From the addon dashboard

The File explorer tab of the addon dashboard gives you access to your files in the FS bucket.

From your favorite FTP client

The Addon information tab of your FS Bucket add-on displays the information you need to connect to your bucket using FTP.

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