Supported Backends - Rustic Core

Rustic supports multiple backend types for storing repository data. Each backend provides the same interface through the ReadBackend and WriteBackend traits, allowing you to choose the storage solution that best fits your needs.

SupportedBackend Enum

pub enum SupportedBackend {
    Local,
    #[cfg(feature = "rclone")]
    Rclone,
    #[cfg(feature = "rest")]
    Rest,
    #[cfg(feature = "opendal")]
    OpenDAL,
}

The backend type is determined from the repository URL prefix:

local: or no prefix → Local
rclone: → Rclone
rest: → REST
opendal: → OpenDAL

Local Backend

Stores repository data on the local filesystem or network-mounted storage.

Features

Direct filesystem access
Fastest performance for local storage
Post-create and post-delete command hooks
Automatic directory structure creation
Supports all major filesystems

Repository Format

local:/path/to/repo      # Unix
local:C:\path\to\repo   # Windows
/path/to/repo            # Unix (implicit)
C:\path\to\repo         # Windows (implicit)

Configuration Options

use rustic_backend::{LocalBackend, BackendOptions};
use std::collections::BTreeMap;

let mut options = BTreeMap::new();
options.insert(
    "post-create-command".to_string(),
    "echo Created %file of type %type with id %id".to_string()
);
options.insert(
    "post-delete-command".to_string(),
    "echo Deleted %file".to_string()
);

let backend = LocalBackend::new("/path/to/repo", options)?;

Options:

post-create-command - Command to run after creating a file
post-delete-command - Command to run after deleting a file

Command Placeholders:

%file - Full file path
%type - File type directory name (e.g., “snapshots”, “data”)
%id - Hexadecimal file ID

Directory Structure

repo/
├── config              # Repository configuration
├── keys/               # Encryption keys
├── snapshots/          # Snapshot metadata
├── index/              # Pack file indices
└── data/               # Pack files (256 subdirectories)
    ├── 00/
    ├── 01/
    ├── ...
    └── ff/

Usage Examples

use rustic_backend::LocalBackend;
use rustic_core::{ReadBackend, WriteBackend, FileType};
use bytes::Bytes;

// Create backend
let backend = LocalBackend::new("/backup/repo", vec![])?;

// Initialize repository
backend.create()?;

// Write data
let data = Bytes::from("snapshot data");
backend.write_bytes(FileType::Snapshot, &snapshot_id, true, data)?;

// Read data
let snapshots = backend.list(FileType::Snapshot)?;
let data = backend.read_full(FileType::Snapshot, &snapshots[0])?;

REST Backend

Connects to a REST server compatible with the restic REST protocol.

Features

HTTP/HTTPS transport
Retry logic with exponential backoff
Custom CA certificates and client certificates
Configurable timeouts
Password authentication via URL
Range request support for partial reads

Repository Format

rest:http://localhost:8000
rest:https://backup.example.com/repo
rest:https://user:[email protected]/repo

Configuration Options

use rustic_backend::RestBackend;
use std::collections::BTreeMap;

let mut options = BTreeMap::new();
options.insert("retry".to_string(), "5".to_string());
options.insert("timeout".to_string(), "10m".to_string());
options.insert("cacert".to_string(), "/path/to/ca.pem".to_string());
options.insert("tls-client-cert".to_string(), "/path/to/client.pem".to_string());

let backend = RestBackend::new(
    "https://backup.example.com/repo",
    options
)?;

Options:

retry - Retry attempts ("false", "off", "default" [5], or a number)
timeout - Request timeout (e.g., "10m", "30s", "600" for seconds)
cacert - Path to CA certificate file for verifying server
tls-client-cert - Path to client certificate for mutual TLS

REST Server Compatibility

The backend is compatible with:

restic REST server
rustic-server
Any server implementing the restic REST protocol

Usage Examples

use rustic_backend::RestBackend;
use rustic_core::{ReadBackend, WriteBackend};

// Basic connection
let backend = RestBackend::new(
    "https://backup.example.com",
    vec![]
)?;

// With authentication
let backend = RestBackend::new(
    "https://user:[email protected]",
    vec![]
)?;

// With custom timeout and retry
let backend = RestBackend::new(
    "https://backup.example.com",
    vec![
        ("timeout".to_string(), "5m".to_string()),
        ("retry".to_string(), "10".to_string()),
    ]
)?;

// Create repository
backend.create()?;  // Sends POST to /?create=true

Rclone Backend

Uses rclone to access any of the 70+ cloud storage providers that rclone supports.

Features

Access to 70+ cloud providers via rclone
Automatic rclone process management
Secure authentication with random credentials
Automatic REST server detection
Version checking for security
Passes through all REST backend options

Repository Format

rclone:remote:path/to/repo
rclone:gdrive:backup/rustic-repo
rclone:s3:bucket/repo
rclone:b2:bucket-name/repo

Requirements

rclone >= 1.52.2 installed and in PATH
Configured rclone remote

Configuration Options

use rustic_backend::RcloneBackend;
use std::collections::BTreeMap;

let mut options = BTreeMap::new();
options.insert(
    "rclone-command".to_string(),
    "rclone serve restic --addr localhost:8080".to_string()
);
options.insert("use-password".to_string(), "true".to_string());

// Plus any REST backend options
options.insert("timeout".to_string(), "5m".to_string());

let backend = RcloneBackend::new("remote:path", options)?;

Options:

rclone-command - Custom rclone command (default: "rclone serve restic --addr localhost:0")
use-password - Enable authentication (default: true, requires rclone >= 1.52.2)
rest-url - Explicit REST URL to use (skips auto-detection)
Plus all REST backend options

How It Works

Spawns an rclone process serving the restic REST protocol
Automatically detects the REST server URL from rclone output
Generates random username/password for authentication
Creates a REST backend connected to the rclone server
Cleans up rclone process on drop

Usage Examples

use rustic_backend::RcloneBackend;
use std::collections::BTreeMap;

// Google Drive
let backend = RcloneBackend::new(
    "gdrive:backup/repo",
    BTreeMap::new()
)?;

// Backblaze B2
let backend = RcloneBackend::new(
    "b2:my-bucket/rustic-backup",
    BTreeMap::new()
)?;

// With custom rclone command
let mut options = BTreeMap::new();
options.insert(
    "rclone-command".to_string(),
    "rclone serve restic --addr 127.0.0.1:9090 --verbose".to_string()
);

let backend = RcloneBackend::new(
    "remote:path",
    options
)?;

OpenDAL Backend

Uses Apache OpenDAL for access to multiple cloud storage providers.

Features

Support for 40+ storage services
Native implementation (no external processes)
Retry logic with jitter
Connection pooling
Bandwidth throttling
Concurrent request limiting
Parallel directory creation for initialization

Repository Format

opendal:s3
opendal:gcs
opendal:azblob
opendal:fs

The scheme after opendal: determines the storage service. Provider-specific options are passed in the options map.

Configuration Options

use rustic_backend::OpenDALBackend;
use std::collections::BTreeMap;

let mut options = BTreeMap::new();

// General options
options.insert("retry".to_string(), "5".to_string());
options.insert("connections".to_string(), "10".to_string());
options.insert("throttle".to_string(), "10MB,50MB".to_string());

// S3-specific options
options.insert("bucket".to_string(), "my-backup-bucket".to_string());
options.insert("region".to_string(), "us-west-2".to_string());
options.insert("access_key_id".to_string(), "AKIAIOSFODNN7EXAMPLE".to_string());
options.insert("secret_access_key".to_string(), "wJalrXUtnFEMI/K7MDENG".to_string());

let backend = OpenDALBackend::new("s3", options)?;

General Options:

retry - Retry attempts ("false", "off", "default" [5], or a number)
connections - Maximum concurrent connections
throttle - Bandwidth limit (format: "<bandwidth>,<burst>", e.g., "10MB,50MB")

Throttle Format:

Uses byte size units: kB, MB, GB, kiB, MiB, GiB
Format: "bandwidth,burst"
Example: "10MB,50MB" = 10MB/s bandwidth, 50MB burst

Supported Services

Amazon S3

let mut options = BTreeMap::new();
options.insert("bucket".to_string(), "my-bucket".to_string());
options.insert("region".to_string(), "us-east-1".to_string());
options.insert("access_key_id".to_string(), "...".to_string());
options.insert("secret_access_key".to_string(), "...".to_string());

let backend = OpenDALBackend::new("s3", options)?;

Google Cloud Storage

let mut options = BTreeMap::new();
options.insert("bucket".to_string(), "my-bucket".to_string());
options.insert("credential".to_string(), "path/to/service-account.json".to_string());

let backend = OpenDALBackend::new("gcs", options)?;

Azure Blob Storage

let mut options = BTreeMap::new();
options.insert("container".to_string(), "my-container".to_string());
options.insert("account_name".to_string(), "mystorageaccount".to_string());
options.insert("account_key".to_string(), "...".to_string());

let backend = OpenDALBackend::new("azblob", options)?;

Local Filesystem (via OpenDAL)

let mut options = BTreeMap::new();
options.insert("root".to_string(), "/path/to/repo".to_string());

let backend = OpenDALBackend::new("fs", options)?;

Other Supported Services

Object Storage: MinIO, Wasabi, DigitalOcean Spaces, Cloudflare R2
Cloud Providers: Alibaba Cloud OSS, Tencent Cloud COS, Huawei Cloud OBS
Specialized: WebDAV, HTTP, IPFS, Redis, Etcd, and many more

See the OpenDAL documentation for the complete list and provider-specific options.

Usage Examples

use rustic_backend::OpenDALBackend;
use std::collections::BTreeMap;
use rustic_core::{ReadBackend, WriteBackend};

// S3 with throttling
let mut options = BTreeMap::new();
options.insert("bucket".to_string(), "backups".to_string());
options.insert("region".to_string(), "us-west-2".to_string());
options.insert("throttle".to_string(), "5MB,20MB".to_string());
options.insert("connections".to_string(), "5".to_string());

let backend = OpenDALBackend::new("s3", options)?;
backend.create()?;

// Google Cloud Storage
let mut options = BTreeMap::new();
options.insert("bucket".to_string(), "my-backups".to_string());
options.insert("credential".to_string(), "key.json".to_string());
options.insert("retry".to_string(), "10".to_string());

let backend = OpenDALBackend::new("gcs", options)?;

Feature Flags

Backend support is controlled by cargo features:

[dependencies]
rustic_backend = { version = "0.1", features = ["opendal", "rclone", "rest"] }

Default features: opendal, rclone, rest

opendal - Enables OpenDAL backend
rclone - Enables Rclone backend
rest - Enables REST backend

The Local backend is always available.

Choosing a Backend

Local

Best for: Local backups, NAS, network-mounted storage Pros:

Fastest performance
Simplest setup
No external dependencies
Command hooks for integration

Cons:

Limited to accessible filesystems
No built-in cloud support

REST

Best for: Self-hosted REST servers, custom server implementations Pros:

Simple HTTP protocol
Works with existing REST servers
Good for self-hosted solutions
TLS support

Cons:

Requires running a server
Network latency

Rclone

Best for: Quick cloud access, many providers, existing rclone configs Pros:

70+ cloud providers
Reuses rclone configuration
Mature and well-tested
Easy cloud migration

Cons:

External rclone dependency
Extra process overhead
Slightly slower than native implementations

OpenDAL

Best for: Production cloud deployments, performance-critical applications Pros:

Native implementation
Better performance than rclone
Advanced features (throttling, connection pooling)
No external processes

Cons:

Fewer providers than rclone
Provider-specific configuration
More complex setup

Backend Traits - Core backend interface
Backend Options - Configuration structure
Repository - Using backends with repositories

Core API

Operations

Data Types

Backends

​SupportedBackend Enum

​Local Backend

​Features

​Repository Format

​Configuration Options

​Directory Structure

​Usage Examples

​REST Backend

​Features

​Repository Format

​Configuration Options

​REST Server Compatibility

​Usage Examples

​Rclone Backend

​Features

​Repository Format

​Requirements

​Configuration Options

​How It Works

​Usage Examples

​OpenDAL Backend

​Features

​Repository Format

​Configuration Options

​Supported Services

​Amazon S3

​Google Cloud Storage

​Azure Blob Storage

​Local Filesystem (via OpenDAL)

​Other Supported Services

​Usage Examples

​Feature Flags

​Choosing a Backend

​Local

​REST

​Rclone

​OpenDAL

​Related Documentation

Build docs developers (and LLMs) love

SupportedBackend Enum

Local Backend

Features

Repository Format

Configuration Options

Directory Structure

Usage Examples

REST Backend

Features

Repository Format

Configuration Options

REST Server Compatibility

Usage Examples

Rclone Backend

Features

Repository Format

Requirements

Configuration Options

How It Works

Usage Examples

OpenDAL Backend

Features

Repository Format

Configuration Options

Supported Services

Amazon S3

Google Cloud Storage

Azure Blob Storage

Local Filesystem (via OpenDAL)

Other Supported Services

Usage Examples

Feature Flags

Choosing a Backend

Local

REST

Rclone

OpenDAL

Related Documentation