How are go migration steps invoked by Goose ?

[chmike]

I’m pretty impressed by goose. I just tried to add a go migration and sow that it added a file containing

package migrations

import (
	"context"
	"database/sql"
	"github.com/pressly/goose/v3"
)

func init() {
	goose.AddMigrationContext(upTest, downTest)
}

func upTest(ctx context.Context, tx *sql.Tx) error {
	// This code is executed when the migration is applied.
	return nil
}

func downTest(ctx context.Context, tx *sql.Tx) error {
	// This code is executed when the migration is rolled back.
	return nil
}

Which is impressively lightweight.

How are these compiled and invoked ? Are they loaded as dynamic libraries ?

If yes, isn’t there the constrain that they should all be compiled with the same compiler version ?

[mfridman]

Nope, you blank import the migrations package in your program. It does mean you'll have to either build your own goose binary, or just use it in your program via the goose provider. You can also use WithGoMigrations and just pass those in directly, docs: https://pressly.github.io/goose/documentation/provider/#withgomigrations

[chmike]

Does it mean that we have to recompile our goose program whenever a go migration is added ?
Where could I find a detailed tutorial how to use my own go migration steps ?