package main import ( "fmt" "strings" "github.com/jmoiron/sqlx" "github.com/knadh/koanf" "github.com/knadh/listmonk/internal/migrations" "github.com/knadh/stuffbin" "github.com/lib/pq" "golang.org/x/mod/semver" ) // migFunc represents a migration function for a particular version. // fn (generally) executes database migrations and additionally // takes the filesystem and config objects in case there are additional bits // of logic to be performed before executing upgrades. fn is idempotent. type migFunc struct { version string fn func(*sqlx.DB, stuffbin.FileSystem, *koanf.Koanf) error } // migList is the list of available migList ordered by the semver. // Each migration is a Go file in internal/migrations named after the semver. // The functions are named as: v0.7.0 => migrations.V0_7_0() and are idempotent. var migList = []migFunc{ {"v0.4.0", migrations.V0_4_0}, {"v0.7.0", migrations.V0_7_0}, } // upgrade upgrades the database to the current version by running SQL migration files // for all version from the last known version to the current one. func upgrade(db *sqlx.DB, fs stuffbin.FileSystem, prompt bool) { if prompt { var ok string fmt.Printf("** IMPORTANT: Take a backup of the database before upgrading.\n") fmt.Print("continue (y/n)? ") if _, err := fmt.Scanf("%s", &ok); err != nil { lo.Fatalf("error reading value from terminal: %v", err) } if strings.ToLower(ok) != "y" { fmt.Println("upgrade cancelled") return } } _, toRun, err := getPendingMigrations(db) if err != nil { lo.Fatalf("error checking migrations: %v", err) } // No migrations to run. if len(toRun) == 0 { lo.Printf("no upgrades to run. Database is up-to-date.") return } // Execute migrations in succession. for _, m := range toRun { lo.Printf("running migration %s", m.version) if err := m.fn(db, fs, ko); err != nil { lo.Fatalf("error running migration %s: %v", m.version, err) } // Record the migration version in the settings table. There was no // settings table until v0.7.0, so ignore the no-table errors. if err := recordMigrationVersion(m.version, db); err != nil { if isTableNotExistErr(err) { continue } lo.Fatalf("error recording migration version %s: %v", m.version, err) } } lo.Printf("upgrade complete") } // checkUpgrade checks if the current database schema matches the expected // binary version. func checkUpgrade(db *sqlx.DB) { lastVer, toRun, err := getPendingMigrations(db) if err != nil { lo.Fatalf("error checking migrations: %v", err) } // No migrations to run. if len(toRun) == 0 { return } var vers []string for _, m := range toRun { vers = append(vers, m.version) } lo.Fatalf(`there are %d pending database upgrade(s): %v. The last upgrade was %s. Backup the database and run listmonk --upgrade`, len(toRun), vers, lastVer) } // getPendingMigrations gets the pending migrations by comparing the last // recorded migration in the DB against all migrations listed in `migrations`. func getPendingMigrations(db *sqlx.DB) (string, []migFunc, error) { lastVer, err := getLastMigrationVersion() if err != nil { return "", nil, err } // Iterate through the migration versions and get everything above the last // last upgraded semver. var toRun []migFunc for i, m := range migList { if semver.Compare(m.version, lastVer) > 0 { toRun = migList[i:] break } } return lastVer, toRun, nil } // getLastMigrationVersion returns the last migration semver recorded in the DB. // If there isn't any, `v0.0.0` is returned. func getLastMigrationVersion() (string, error) { var v string if err := db.Get(&v, ` SELECT COALESCE( (SELECT value->>-1 FROM settings WHERE key='migrations'), 'v0.0.0')`); err != nil { if isTableNotExistErr(err) { return "v0.0.0", nil } return v, err } return v, nil } // isPqNoTableErr checks if the given error represents a Postgres/pq // "table does not exist" error. func isTableNotExistErr(err error) bool { if p, ok := err.(*pq.Error); ok { // `settings` table does not exist. It was introduced in v0.7.0. if p.Code == "42P01" { return true } } return false }