FluxForge

A database schema converter and migration engine for MySQL and PostgreSQL written in Rust.

Features

• Schema Extraction: Extract complete database schemas including tables, columns and indices (foreign keys are not yet supported)
• Type Mapping: Configurable type conversion between MySQL and PostgreSQL with built-in sensible defaults
• Data Replication: Stream and replicate data efficiently with chunked transfers and progress tracking
• Verification: Optional row-by-row verification to ensure data integrity after migration
• Dependency Resolution: Automatic topological sorting of tables based on foreign key relationships
• Dual Mode: Use as a standalone CLI tool or integrate as a library in your Rust projects
• Supported Migrations:
  • MySQL → PostgreSQL ✅
  • MySQL → MySQL ✅
  • PostgreSQL → PostgreSQL ✅

Installation

As a Library

Add FluxForge to your Cargo.toml:

[dependencies]
fluxforge = "0.3.0"

As a Standalone Binary

Install via cargo:

cargo add fluxforge

Usage

As a Library

use fluxforge::{drivers, ops, core::ForgeConfig};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    // Load configuration (or use default)
    let config = ForgeConfig::default();
    
    // Create database drivers
    let source = drivers::create_driver(
        "mysql://user:pass@localhost:3306/source_db",
        &config
    ).await?;
    
    let target = drivers::create_driver(
        "postgres://user:pass@localhost:5432/target_db",
        &config
    ).await?;
    
    // Extract schema from source
    let mut schema = source.fetch_schema(&config).await?;
    
    // Sort tables by dependencies
    let sorted_tables = ops::sort_tables_by_dependencies(&schema)?;
    schema.tables = sorted_tables;
    
    // Apply schema to target
    target.diff_and_apply_schema(&schema, &config, false, false, true).await?;
    
    // Replicate data with verification
    ops::replicate_data(
        source.as_ref(),
        target.as_ref(),
        &schema,
        false,  // dry_run
        false,  // verbose
        true,   // halt_on_error
        true    // verify_after_write
    ).await?;
    
    println!("Migration completed successfully!");
    Ok(())
}

As a CLI Tool

Extract Schema to JSON

Extract a database schema into an intermediate JSON format:

fluxforge extract \
  --source "mysql://user:pass@localhost/mydb" \
  --schema schema.json \
  --config mapping.toml \
  --verbose

Migrate Schema Only

Apply schema changes without transferring data:

fluxforge migrate \
  --source "mysql://user:pass@localhost/source_db" \
  --target "postgres://user:pass@localhost/target_db" \
  --config mapping.toml \
  --dry-run \
  --verbose

Or migrate from a previously extracted schema file:

fluxforge migrate \
  --schema schema.json \
  --target "postgres://user:pass@localhost/target_db" \
  --config mapping.toml

Full Replication (Schema + Data)

Replicate both schema and data from source to target:

fluxforge replicate \
  --source "mysql://user:pass@localhost/source_db" \
  --target "postgres://user:pass@localhost/target_db" \
  --config mapping.toml \
  --dump   data_dump.jsonl \
  --verify \
  --halt-on-error \
  --verbose

Note: The target database must be empty for replication to proceed (data loss protection).

Configuration File Example

Create a mapping.toml file to customize type mappings and transformation rules:

[mysql.types.on_read]
"int" = "integer"
"tinyint" = "smallint"
"double" = "double precision"
"datetime" = "timestamp"
"blob" = "bytea"

[mysql.rules.on_read]
unsigned_int_to_bigint = true

[postgres.types.on_write]
"json" = "jsonb"
"datetimetz" = "timestamptz"

The "examples" folder contains three suggested configuration files:

• mysql2postgres.toml: For MySQL to PostgreSQL
• mysql2mysql.toml: For MySQL to MySQL
• postgres2postgres.toml: For PostgreSQL to PostgreSQL

The settings from mysql2postgres.toml are included in the executable standalone binary as default and are used if no mapping file is selected with --config.

Documentation

Full API documentation is available on docs.rs/fluxforge.

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Minimum Supported Rust Version (MSRV)

This crate requires Rust 1.92 or later.

About Us

FluxForge development is sponsored and led by INS GmbH

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.