psql-migrate

A PostgreSQL database migration tool.

This tool has a few goals:

• Minimal
• Production-friendly
• Transactional DDL
• Warn aggressively about unexpected migration files (especially merge "conflicts")
• Don't build sqlite3 drivers for a postgresql tool

Usage

The tool looks for migrations in a directory, ./migrations by default, with names like 0001_initial.up.sql and 0001_initial.down.sql. As a shortcut, the tool can create empty up and down migration files for you. If you run migrations as part of an automated process, you can use the output of psql-migrate pending to determine when to block production deploys until the migrations are applied manually.

psql-migrate <version> [arguments]
psql-migrate command [arguments]

The commands are:

[number]	Migrate to the given migration version number
latest		Migrate to the latest migration version on disk
create		Create a new up and down migration in the migration directory
version		Print the current migration version
pending		Print true if there are unapplied migrations, or else false

All commands require a connection information, which can be set by command-line flags or environment variables:

--conn-str (env: CONN_STR): lib/pq connection string, e.g.
	"user=xxx dbname=xxx password=xxx"
--migrations-path (env: MIGRATIONS_PATH): Directory containing migration files
	(default: ./migrations)

Structure

The tool is split into a shared library (libmigrate) and a database-specific command-line tool (this library).

If you need to run a non-transactional migration, start the migration file with this line:

-- migrate: no-transaction