Files
webhooker/internal/db/migrations/migrations.go
T
sneak 537374e4cc
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Deploy main eacf1e7 to prod
Replaces #559, which conflicted.

Model: opus-5-5
2026-10-25 01:55:36 +00:00

136 lines
3.2 KiB
Go

// Package migrations holds the schema of each kind of SQLite file
// webhooker writes, as numbered SQL files embedded in the binary, and
// applies it when a file is opened.
//
// Each kind of file has its own directory. In each, 000_migration.sql
// creates only the schema_migrations table, and 001_schema.sql holds
// the whole schema. Before 1.0 a schema change is an edit to
// 001_schema.sql, never a new file.
package migrations
import (
"embed"
"fmt"
"io/fs"
"path"
"strconv"
"strings"
"gorm.io/gorm"
)
// The directories, one for each kind of database file.
const (
// Main is the main database, webhooker.db.
Main = "main"
// Events is a webhook's event database, events-{uuid}.db.
Events = "events"
// Archive is a database target's archive file.
Archive = "archive"
)
//go:embed main/*.sql events/*.sql archive/*.sql
var files embed.FS
// Apply runs each SQL file in dir, which is Main, Events or Archive,
// that the database has not had yet, in the order of the number its
// name starts with, and records that number in schema_migrations.
// 000_migration.sql creates that table and records itself, so it runs
// first, and only when the table is missing.
//
// It all runs in one transaction, so a failure leaves the file as it
// was.
func Apply(db *gorm.DB, dir string) error {
return db.Transaction(func(tx *gorm.DB) error {
var tables int
// Row().Scan, not (*gorm.DB).Scan: see internal/gormlog.
err := tx.Raw(
"SELECT count(*) FROM sqlite_master "+
"WHERE type = 'table' AND name = ?",
"schema_migrations",
).Row().Scan(&tables)
if err != nil {
return fmt.Errorf("looking for schema_migrations: %w", err)
}
if tables == 0 {
err = run(tx, path.Join(dir, "000_migration.sql"))
if err != nil {
return err
}
}
// fs.Glob lists the files in name order, which is number order.
names, err := fs.Glob(files, path.Join(dir, "*.sql"))
if err != nil {
return fmt.Errorf("listing migrations: %w", err)
}
for _, name := range names {
err = applyOnce(tx, name)
if err != nil {
return err
}
}
return nil
})
}
// applyOnce runs the migration file name and records its number,
// unless schema_migrations already has that number.
func applyOnce(tx *gorm.DB, name string) error {
number, _, _ := strings.Cut(path.Base(name), "_")
version, err := strconv.Atoi(number)
if err != nil {
return fmt.Errorf("numbering migration %s: %w", name, err)
}
var applied int
err = tx.Raw(
"SELECT count(*) FROM schema_migrations WHERE version = ?",
version,
).Row().Scan(&applied)
if err != nil {
return fmt.Errorf("checking migration %s: %w", name, err)
}
if applied > 0 {
return nil
}
err = run(tx, name)
if err != nil {
return err
}
err = tx.Exec(
"INSERT INTO schema_migrations (version) VALUES (?)", version,
).Error
if err != nil {
return fmt.Errorf("recording migration %s: %w", name, err)
}
return nil
}
// run executes every statement in the migration file name.
func run(tx *gorm.DB, name string) error {
script, err := files.ReadFile(name)
if err != nil {
return fmt.Errorf("reading migration %s: %w", name, err)
}
err = tx.Exec(string(script)).Error
if err != nil {
return fmt.Errorf("applying migration %s: %w", name, err)
}
return nil
}