gonews/database/migrations/exported.go

82 lines
2.5 KiB
Go

package migrations
import (
// stdlib
"database/sql"
"log"
"os"
"strconv"
// other
"github.com/pressly/goose"
)
func Initialize() {
log.Println("Initializing database migrations...")
_ = goose.SetDialect("postgres")
goose.AddNamedMigration("1_create_users_table.go", CreateUsersTableUp, CreateUsersTableDown)
// Migrations should be registered here.
}
func Migrate(db *sql.DB) {
log.Println("Starting database migration procedure...")
// Prepare migrations configuration.
var action = "UP"
actionFromEnv, actionFound := os.LookupEnv("DATABASE_ACTION")
if actionFound {
log.Println("Migration action override: " + actionFromEnv)
action = actionFromEnv
} else {
log.Println("Executing default migration action (UP)")
}
var count int64
countFromEnv, countFound := os.LookupEnv("DATABASE_COUNT")
if countFound {
log.Println("Migration count override: " + countFromEnv)
countAsInt, err := strconv.ParseInt(countFromEnv, 10, 64)
if err != nil {
log.Fatalln("Failed to convert count gathered from DATABASE_COUNT to integer")
}
count = countAsInt
} else {
log.Println("Applying or rollback this count of migrations: " + countFromEnv + ". 0 - all.")
}
// Execute migrations.
var err error
currentDBVersion, gooseerr := goose.GetDBVersion(db)
if gooseerr != nil {
log.Fatalln("Failed to get database version: " + gooseerr.Error())
}
log.Println("Current database version obtained: " + strconv.Itoa(int(currentDBVersion)))
if action == "UP" && count == 0 {
log.Println("Applying all unapplied migrations...")
err = goose.Up(db, ".")
} else if action == "UP" && count != 0 {
newVersion := currentDBVersion + count
log.Println("Migrating database to specific version: " + strconv.Itoa(int(newVersion)))
err = goose.UpTo(db, ".", newVersion)
} else if action == "DOWN" && count == 0 {
log.Println("Downgrading database to zero state, you'll need to re-apply migrations!")
err = goose.Down(db, ".")
log.Fatalln("Database downgraded to zero state. You have to re-apply migrations")
} else if action == "DOWN" && count != 0 {
newVersion := currentDBVersion - count
log.Println("Downgrading database to specific version: " + strconv.Itoa(int(newVersion)))
err = goose.DownTo(db, ".", newVersion)
} else {
log.Fatalln("Unsupported set of migration parameters, cannot continue: " + action + "/" + countFromEnv)
}
if err != nil {
log.Fatalln("Failed to execute migration sequence: " + err.Error())
}
log.Println("Database migrated successfully")
}