wrench

wrench is a schema management tool for Cloud Spanner.

Please feel free to report issues and send pull requests, but note that this application is not officially supported as part of the Cloud Spanner product.

$ cat ./_examples/schema.sql
CREATE TABLE Singers (
  SingerID STRING(36) NOT NULL,
  FirstName STRING(1024),
) PRIMARY KEY(SingerID);

# create database with ./_examples/schema.sql
$ wrench create --directory ./_examples

# create migration file
$ wrench migrate create --directory ./_examples
_examples/migrations/000001.sql is created

# edit _examples/migrations/000001.sql
$ cat ./_examples/migrations/000001.sql
ALTER TABLE Singers ADD COLUMN LastName STRING(1024);

# execute migration
$ wrench migrate up --directory ./_examples

# load ddl from database to file ./_examples/schema.sql
$ wrench load --directory ./_examples

# finally, we have successfully migrated database!
$ cat ./_examples/schema.sql
CREATE TABLE SchemaMigrations (
  Version INT64 NOT NULL,
  Dirty BOOL NOT NULL,
) PRIMARY KEY(Version);

CREATE TABLE Singers (
  SingerID STRING(36) NOT NULL,
  FirstName STRING(1024),
  LastName STRING(1024),
) PRIMARY KEY(SingerID);

Installation

Get binary from release page. Or, you can use Docker container: mercari/wrench.

Usage

Prerequisite

export SPANNER_PROJECT_ID=your-project-id
export SPANNER_INSTANCE_ID=your-instance-id
export SPANNER_DATABASE_ID=your-database-id

You can also specify project id, instance id and database id by passing them as command arguments.

Create database

$ wrench create --directory ./_examples

This creates the database with ./_examples/schema.sql.

Drop database

$ wrench drop

This just drops the database.

Reset database

wrench reset --directory ./_examples

This drops the database and then re-creates with ./_examples/schema.sql. Equivalent to drop and then create.

Load schema from database to file

$ wrench load --directory ./_examples

This loads schema DDL from database and writes it to ./_examples/schema.sql.

Create migration file

$ wrench migrate create --directory ./_examples

This creates a next migration file like _examples/migrations/000001.sql. You will write your own migration DDL to this file.

Execute migrations

$ wrench migrate up --directory ./_examples

This executes migrations. This also creates SchemaMigrations table into your database to manage schema version if it does not exist.

Apply single DDL/DML

$ wrench apply --ddl ./_examples/ddl.sql

This applies single DDL or DML.

Use wrench [command] --help for more information about a command.

Contributions

Please read the contribution guidelines before submitting pull requests.

How to run tests locally

1. Start spanner emulator.

$ docker run --rm -it -p 9010:9010 -p 9020:9020 gcr.io/cloud-spanner-emulator/emulator:1.5.0

2. Initialize a spanner instance.

$ make setup-emulator

3. Run tests

$ make test

License

Copyright 2019 Mercari, Inc.

Licensed under the MIT License.