Storage Providers

ALTCHA Sentinel supports remote and local storage providers for handling file uploads in forms and storing database snapshots.

Supported Providers

The following storage providers are currently supported:

• AWS S3
• Azure Blob Storage
• Local File System

AWS S3

To use AWS S3 or any S3-compatible service (e.g., MinIO, Cloudflare R2), set the following environment variables:

• STORAGE_PROVIDER=s3
• STORAGE_S3_URL

Credentials can be provided through the standard AWS environment variables:

• AWS_ACCESS_KEY_ID
• AWS_SECRET_ACCESS_KEY
• AWS_REGION

Alternatively, credentials can be embedded in the URL using the username:password@host format.

Example:

STORAGE_PROVIDER=s3
STORAGE_S3_URL=https://s3.eu-west-1.amazonaws.com/?bucket=my-bucket&prefix=storage

URL Parameters:

Parameter	Description
bucket	S3 bucket name.
prefix	Optional path prefix within the bucket.
region	AWS region. Defaults to auto for non-AWS endpoints.

Azure Blob Storage

To use Azure Blob Storage, set the following environment variables:

• STORAGE_PROVIDER=azure
• STORAGE_AZURE_CONTAINER
• STORAGE_AZURE_CONNECTION_STRING

Local File System

By default, Sentinel uses the local file system for storage. Files are stored in the data directory.

• STORAGE_PROVIDER=local (default)
• STORAGE_LOCAL_DIR (defaults to {DATA_DIR}/storage)

Snapshots

Database snapshots can use a different storage provider than the one used for file uploads. To configure this, use the same environment variables as above, prefixed with SNAPSHOTS_. For example:

• SNAPSHOTS_STORAGE_PROVIDER
• SNAPSHOTS_STORAGE_S3_URL
• SNAPSHOTS_STORAGE_AZURE_CONTAINER
• SNAPSHOTS_STORAGE_LOCAL_DIR

This separation allows you to store snapshots independently of form uploads—ideal for backup and redundancy strategies.