cli: add database migration client

cmd/migrate.go

@@ -0,0 +1,248 @@
+package cmd
+
+import (
+	"bufio"
+	"database/sql"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/ditointernet/go-dito/lib/env"
+	"github.com/golang-migrate/migrate"
+	"github.com/golang-migrate/migrate/database/postgres"
+	"github.com/spf13/cobra"
+)
+
+// Migration is a structure that encapsulates migration's dependencies
+type Migration struct {
+	migrate *migrate.Migrate
+}
+
+var (
+	databaseURI     string
+	prodEnvironment bool
+	dbDriver        string
+	db              *sql.DB
+	migration       Migration
+)
+
+func newMigration(db *sql.DB, source string) (Migration, error) {
+	driver, err := postgres.WithInstance(db, &postgres.Config{})
+	if err != nil {
+		return Migration{}, err
+	}
+
+	m, err := migrate.NewWithDatabaseInstance(source, "postgres", driver)
+	if err != nil {
+		return Migration{}, err
+	}
+
+	return Migration{migrate: m}, nil
+}
+
+func init() {
+	databaseURI = env.GetString("DATABASE_URI")
+	prodEnvironment = env.GetBool("PROD_ENVIRONMENT", false)
+
+	if prodEnvironment {
+		dbDriver = "cloudsqlpostgres"
+	} else {
+		dbDriver = "postgres"
+	}
+
+	db = newDBConnection(dbDriver, databaseURI)
+
+	var err error
+	migration, err = newMigration(db, "file://./migrations")
+	if err != nil {
+		fmt.Printf("error when creating migration: %s\n", err.Error())
+		os.Exit(1)
+	}
+}
+
+var (
+	migrateCmd = &cobra.Command{
+		Use:     "migrate",
+		Version: "0.0.1",
+	}
+
+	upCmd = &cobra.Command{
+		Use:  "up",
+		Long: "looks at the currently active migration version and will migrate up",
+		Run: func(cmd *cobra.Command, args []string) {
+			steps, err := cmd.Flags().GetUint("steps")
+			if err != nil {
+				fmt.Printf("error when fetching flag steps: %v\n", err)
+				os.Exit(1)
+			}
+
+			fmt.Printf("migrating up steps=%v\n", steps)
+
+			err = migration.runMigrationUp(steps)
+			if err != nil {
+				fmt.Printf("error when migrating database: %v\n", err)
+				os.Exit(1)
+			}
+		},
+	}
+
+	downCmd = &cobra.Command{
+		Use:  "down",
+		Long: "",
+		Run: func(cmd *cobra.Command, args []string) {
+			steps, err := cmd.Flags().GetUint("steps")
+			if err != nil {
+				fmt.Printf("error when fetching flag steps: %v\n", err)
+				os.Exit(1)
+			}
+
+			reader := bufio.NewReader(os.Stdin)
+
+			for {
+				fmt.Println("The 'down' operation may results data loss. Do you confirm [y/n]? ")
+				input, _ := reader.ReadString('\n')
+				input = strings.TrimSpace(input)
+
+				switch input {
+				case "n":
+					os.Exit(0)
+				case "y":
+					fmt.Printf("migrating down steps=%v\n", steps)
+					err = migration.runMigrationDown(steps)
+					if err != nil {
+						fmt.Printf("error when migrating database: %v\n", err)
+						os.Exit(1)
+					}
+				default:
+					fmt.Println("Invalid option.")
+					os.Exit(0)
+				}
+			}
+		},
+	}
+
+	seedCmd = &cobra.Command{
+		Use:  "seed",
+		Long: "a flag that states if it will run the local database seed",
+		Run: func(cmd *cobra.Command, args []string) {
+			fmt.Println("seeding the local database...")
+
+			var seedFiles []string
+			err := filepath.Walk("./seed", func(path string, info os.FileInfo, err error) error {
+				if err != nil {
+					return err
+				}
+				if info.IsDir() {
+					return nil
+				}
+				if matched, err := filepath.Match("*.sql", filepath.Base(path)); err != nil {
+					return err
+				} else if matched {
+					seedFiles = append(seedFiles, path)
+				}
+				return nil
+			})
+			if err != nil {
+				fmt.Println(err.Error())
+				os.Exit(1)
+			}
+
+			for _, seedFile := range seedFiles {
+				fmt.Printf("running %s...\n", seedFile)
+				sql, err := ioutil.ReadFile(seedFile)
+				if err != nil {
+					fmt.Println(err.Error())
+					os.Exit(1)
+				}
+
+				_, err = db.Exec(string(sql))
+				if err != nil {
+					fmt.Println(err.Error())
+					os.Exit(1)
+				}
+
+				fmt.Printf("ran %s\n", seedFile)
+			}
+		},
+	}
+)
+
+func newDBConnection(dbDriver string, databaseURI string) *sql.DB {
+	db, err := sql.Open(dbDriver, databaseURI)
+	if err != nil {
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+
+	if err := db.Ping(); err != nil {
+		fmt.Println(err.Error())
+		os.Exit(1)
+	}
+
+	db.SetMaxOpenConns(10)
+
+	fmt.Println("got connected to database")
+
+	return db
+}
+
+func (c Migration) runMigrationUp(steps uint) error {
+	if steps > 0 {
+		return c.runMigrationSteps(int(steps))
+	}
+
+	version, dirty, _ := c.migrate.Version()
+	if dirty {
+		return errors.New("database is in dirty state, solve version in 'schema_migrations' table manually")
+	}
+
+	if err := c.migrate.Up(); err != nil {
+		return c.handleMigrationError(err, version)
+	}
+
+	return nil
+}
+
+func (c Migration) runMigrationDown(steps uint) error {
+	if steps > 0 {
+		return c.runMigrationSteps(int(steps) * -1)
+	}
+
+	version, dirty, _ := c.migrate.Version()
+	if dirty {
+		return errors.New("database is in dirty state, solve version in 'schema_migrations' table manually")
+	}
+
+	if err := c.migrate.Down(); err != nil {
+		return c.handleMigrationError(err, version)
+	}
+
+	return nil
+}
+
+func (c Migration) runMigrationSteps(steps int) error {
+	err := c.migrate.Steps(steps)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (c Migration) handleMigrationError(err error, previousVersion uint) error {
+	if err.Error() == "no change" {
+		return nil
+	}
+	if previousVersion > 0 {
+		e := c.migrate.Force(int(previousVersion))
+		if e != nil {
+			return fmt.Errorf("%s: %s", err.Error(), e.Error())
+		}
+		return fmt.Errorf("error on migration, database version was reverted to version %d: %s", previousVersion, err.Error())
+	}
+
+	return err
+}

cmd/root.go

@@ -12,7 +12,14 @@ var rootCmd = &cobra.Command{
 }
 
 func init() {
-	rootCmd.AddCommand(createSvcCmd)
+	migrateCmd.PersistentFlags().UintP(
+		"steps", "s", 0,
+		"number of steps operation. will apply all migrations if not informed or steps equal zero",
+	)
+
+	migrateCmd.AddCommand(upCmd, downCmd, seedCmd)
+
+	rootCmd.AddCommand(createSvcCmd, migrateCmd)
 }
 
 // Execute ...

go.mod

@@ -2,4 +2,9 @@ module github.com/ditointernet/go-dito
 
 go 1.12
 
-require github.com/spf13/cobra v1.0.0
+require (
+	github.com/ditointernet/go-dito/lib/env v1.0.0
+	github.com/golang-migrate/migrate v3.5.4+incompatible
+	github.com/golang-migrate/migrate/v4 v4.14.1
+	github.com/spf13/cobra v1.0.0
+)