Integrant methods for running database migrations using Ragtime.

To install, add the following to your project :dependencies:

[duct/migrator.ragtime "0.3.2"]

This library provides the :duct.migrator/ragtime Integrant key, which takes five options:

{:duct.migrator/ragtime
 {:database   #ig/ref :duct.database/sql
  :logger     #ig/ref :duct/logger
  :strategy   :rebase
  :migrations [#ig/ref :foo.migration/create-foo-table]
  :migrations-table "ragtime_migrations"}}

The :database key should be a SQL database compatible with the Duct database.sql library. For example:

{:duct.database.sql/hikaricp
 {:jdbc-url "jdbc:sqlite:db/foo.sqlite"}}

The :logger key should be a logger compatible with the Duct logger library:

{:duct.logger.timbre/println {}
 :duct.logger/timbre
 {:level    :info
  :appender #ig/ref :duct.logger.timbre/println}}

The :strategy is either :apply-new, :raise-error or :rebase. These correspond to the ragtime strategies with the same names.

The :migrations are an ordered collection of migrations. The easiest way to create these is to use a composite key that is derived from :duct.migrator.ragtime/sql.

{[:duct.migrator.ragtime/sql :foo.migration/create-foo-table]
 {:up   ["CREATE TABLE foo (id int);"]
  :down ["DROP TABLE foo;"]}}

Migrations built in this way expect an :up and a :down key that contain vectors of SQL, either as strings, or URLs to resources on the classpath.

Resources can be specified in the edn configuration file using the #duct/resource tag. For example:

{[:duct.migrator.ragtime/sql :foo.migration/create-foo-table]
 {:up   [#duct/resource "migrations/foo.up.sql"]
  :down [#duct/resource "migrations/foo.down.sql"]}}

The associated SQL files can then be placed in resources/migrations.

Alternatively, you can use the :duct.migrator.ragtime/resources key, which will look for resources in a directory:

{:duct.migrator.ragtime/resources {:path "migrations"}}

A migration resource can either be a pair of SQL files ending in .up.sql and .down.sql, or it can be an edn file ending in .edn that contains a map with an :up and a :down key containing vectors of SQL strings.

You can also specify SQL files in an external directory:

{:duct.migrator.ragtime/directory {:path "example/migrations"}}

It's possible to mix migrations from multiple places. The :migrations key will flatten nested collections, so it's possible to have a configuration like:

{:duct.migrator/ragtime
 {:database   #ig/ref :duct.database/sql
  :logger     #ig/ref :duct/logger
  :strategy   :rebase
  :migrations [#ig/ref :foo.migrations/dev
               #ig/ref :foo.migrations/prod]}

 [:duct.migrator.ragtime/resources :foo.migrations/dev]
 {:path "dev/migrations"}

 [:duct.migrator.ragtime/resources :foo.migrations/prod]
 {:path "prod/migrations"}}

Finally, the :migrations-table optional key corresponds to the ragtime sql-database option with the same name. It is the name of the table to store the applied migrations (defaults to "ragtime_migrations" if not specified).

Copyright © 2020 James Reeves

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.