docs: add SFTPGo guide and custom SFTP note to FS Buckets documentation

content/doc/addons/fs-bucket.md

@@ -156,6 +156,10 @@
 | RSA       | 4096     | `SHA256:yRHC/tAlBpHLlRZ5rwbZ1z+159Bj3yg0VxHf+hXINLg` |
 | RSA       | 4096     | `SHA256:yhn79aqxOGQZ+LXdN1/vIY+jwRIbBamlVT1+HdFoA6o` |
 
+> [!NOTE]
+> The SFTP access to FS Buckets uses Clever Cloud-managed credentials. You cannot add custom SSH keys or manage individual user accounts for FS Bucket access.
+> If you need fine-grained user management and custom SSH key support for SFTP, consider deploying [SFTPGo](/guides/sftpgo/) as a Docker application instead.
+
 ### From your favorite FTP client
 
 The **Add-on information** tab of your FS Bucket add-on displays the information

content/guides/sftpgo.md

@@ -0,0 +1,123 @@
+---
+type: docs
+linkTitle: SFTPGo
+title: SFTPGo
+description: Deploy SFTPGo on Clever Cloud with Docker to set up a custom SFTP server with user management and Cellar S3 storage backend
+keywords:
+- sftpgo
+- sftp
+- ftp
+- file transfer
+- docker
+- cellar
+- s3 storage
+- file management
+- webdav
+aliases:
+- /sftpgo
+---
+
+{{< hextra/hero-subtitle >}}
+  SFTPGo is a modern, open-source SFTP server with multi-user management, a web interface and S3-compatible storage backends like Cellar.
+{{< /hextra/hero-subtitle >}}
+
+## Overview
+
+Clever Cloud provides built-in SFTP access to [FS Buckets](/doc/addons/fs-buckets/), but if you need advanced user management, fine-grained access control, or want to expose files stored in [Cellar](/doc/addons/cellar/) over SFTP, you can deploy SFTPGo as a Docker application.
+
+> [!WARNING] Only the SFTP protocol works out of the box on Clever Cloud
+> FTP (non-encrypted) requires a dedicated TCP port range. Contact [Clever Cloud support](https://console.clever-cloud.com/ticket/center) to enable it.
+
+## Requirements
+
+You need [git](https://git-scm.com/book/en/v2/Getting-Started-Installing-Git) and a [Clever Cloud account](https://console.clever-cloud.com).
+
+## Create and configure resources on Clever Cloud
+
+1. Create a **Docker** application (XS size or above) from the [Console](https://console.clever-cloud.com)
+2. Create a **PostgreSQL** add-on (version 15, XXS Small Space) and link it to your application
+3. Create a **Cellar** add-on for S3-compatible object storage and link it to your application
+4. Enable **TCP redirection** on your Docker application from the Console
+
+## Prepare the project
+
+Initialize a Git repository with a minimal **Dockerfile**:
+
+```bash
+mkdir my-sftpgo && cd my-sftpgo
+git init
+```
+
+Create a **Dockerfile** at the root of the project
+
+```bash
+FROM drakkan/sftpgo:latest
+```
+
+## Set environment variables
+
+Add the following environment variables to your Docker application in the console. Replace placeholder values with the credentials provided by Clever Cloud for your PostgreSQL add-on:
+
+```bash
+CC_DOCKER_EXPOSED_TCP_PORT="2022"
+SFTPGO_DATA_PROVIDER__DRIVER="postgresql"
+SFTPGO_DATA_PROVIDER__HOST="<pg_host>"
+SFTPGO_DATA_PROVIDER__NAME="<pg_dbname>"
+SFTPGO_DATA_PROVIDER__PASSWORD="<pg_password>"
+SFTPGO_DATA_PROVIDER__PORT="<pg_port>"
+SFTPGO_DATA_PROVIDER__USERNAME="<pg_user>"
+```
+
+## Deploy
+
+First, commit and push your code:
+
+```bash
+git add .
+git commit -m "Deploy SFTPGo"
+clever link <your-app-id>
+clever deploy
+```
+
+Or using a Git remote:
+
+```bash
+git remote add clever <your-clever-git-url>
+git push clever master
+
+```
+
+## Initialize SFTPGo
+
+1. Open your application URL in a browser
+2. Follow the setup wizard to create an **admin account**
+
+## Connect Cellar as a storage backend
+
+In the SFTPGo web admin interface, create a new user with an **S3-compatible** filesystem:
+
+| Setting | Value |
+|---------|-------|
+| Bucket | Your Cellar bucket name |
+| Region | FR |
+| Access Key | Your Cellar Key ID |
+| Access Secret | Your Cellar Key Secret |
+| Endpoint | https://cellar-c2.services.clever-cloud.com |
+
+
+## Connect with an SFTP client
+
+Use any SFTP client (such as FileZilla, Cyberduck, or the sftp CLI) with:
+
+- Host: shown in the TCP redirection tab of your application in the console
+- Port: shown in the TCP redirection tab
+- Username & Password: your SFTPGo admin credentials
+
+## 🎓 Learn more
+
+{{< cards >}}
+  {{< card link="/developers/doc/applications/docker" title="Deploy a Docker application" subtitle="How to configure your Docker app" icon="docker" >}}
+  {{< card link="/developers/doc/addons/cellar" title="Cellar Object Storage" subtitle="S3-compatible storage on Clever Cloud" icon="database" >}}
+  {{< card link="/developers/doc/addons/fs-bucket" title="FS Buckets" subtitle="Built-in persistent file storage with SFTP access" icon="database" >}}
+  {{< card link="https://docs.sftpgo.com/" title="SFTPGo Documentation" subtitle="Official SFTPGo documentation" icon="book-open" >}}
+{{< /cards >}}