From 6c77aee7488f41e331fb0a5f2f51f687a9c6e2c4 Mon Sep 17 00:00:00 2001
From: Elliott Minns <elliott.minns@pm.me>
Date: Thu, 7 Nov 2024 14:45:01 -0600
Subject: [PATCH] Use go:embed for migrations

---
 Dockerfile                    |  3 ---
 internal/app/app.go           | 15 +++++++++------
 internal/database/database.go | 17 +++++++++--------
 main.go                       |  6 +++++-
 4 files changed, 23 insertions(+), 18 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 863e22d..f3925e2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -72,12 +72,9 @@ USER appuser
 
 # Copy the executable from the "build" stage.
 COPY --from=build /bin/server /bin/
-COPY ./migrations ./migrations
 COPY ./templates ./templates
 COPY ./static ./static
 
-ENV MIGRATIONS_URL=file://migrations
-
 # Expose the port that the application listens on.
 EXPOSE 8080
 
diff --git a/internal/app/app.go b/internal/app/app.go
index 4d77697..69f0b40 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"html/template"
+	"io/fs"
 	"log/slog"
 	"net/http"
 	"os"
@@ -18,13 +19,14 @@ import (
 )
 
 type App struct {
-	logger *slog.Logger
-	router *http.ServeMux
-	db     *pgxpool.Pool
-	rdb    *redis.Client
+	logger     *slog.Logger
+	router     *http.ServeMux
+	db         *pgxpool.Pool
+	rdb        *redis.Client
+	migrations fs.FS
 }
 
-func New(logger *slog.Logger) *App {
+func New(logger *slog.Logger, migrations fs.FS) *App {
 	router := http.NewServeMux()
 
 	redisAddr, exists := os.LookupEnv("REDIS_ADDR")
@@ -38,13 +40,14 @@ func New(logger *slog.Logger) *App {
 		rdb: redis.NewClient(&redis.Options{
 			Addr: redisAddr,
 		}),
+		migrations: migrations,
 	}
 
 	return app
 }
 
 func (a *App) Start(ctx context.Context) error {
-	db, err := database.Connect(ctx, a.logger)
+	db, err := database.Connect(ctx, a.logger, a.migrations)
 	if err != nil {
 		return fmt.Errorf("failed to connect to db: %w", err)
 	}
diff --git a/internal/database/database.go b/internal/database/database.go
index 7857aae..138bcb9 100644
--- a/internal/database/database.go
+++ b/internal/database/database.go
@@ -4,12 +4,13 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io/fs"
 	"log/slog"
 	"os"
 
 	"github.com/golang-migrate/migrate/v4"
 	_ "github.com/golang-migrate/migrate/v4/database/postgres"
-	_ "github.com/golang-migrate/migrate/v4/source/file"
+	"github.com/golang-migrate/migrate/v4/source/iofs"
 	"github.com/jackc/pgx/v5/pgxpool"
 
 	"github.com/dreamsofcode-io/guestbook/internal/config"
@@ -60,7 +61,7 @@ func dbURL() (string, error) {
 	return cfg.URL(), nil
 }
 
-func Connect(ctx context.Context, logger *slog.Logger) (*pgxpool.Pool, error) {
+func Connect(ctx context.Context, logger *slog.Logger, migrations fs.FS) (*pgxpool.Pool, error) {
 	config, err := loadConfig()
 	if err != nil {
 		return nil, err
@@ -73,17 +74,17 @@ func Connect(ctx context.Context, logger *slog.Logger) (*pgxpool.Pool, error) {
 
 	logger.Debug("Running migrations")
 
-	migrationsURL, exists := os.LookupEnv("MIGRATIONS_PATH")
-	if !exists {
-		migrationsURL = "file://migrations"
-	}
-
 	url, err := dbURL()
 	if err != nil {
 		return nil, err
 	}
 
-	migrator, err := migrate.New(migrationsURL, url)
+	source, err := iofs.New(migrations, "migrations")
+	if err != nil {
+		return nil, fmt.Errorf("failed to create source: %w", err)
+	}
+
+	migrator, err := migrate.NewWithSourceInstance("iofs", source, url)
 	if err != nil {
 		return nil, fmt.Errorf("migrate new: %s", err)
 	}
diff --git a/main.go b/main.go
index fc6f9d4..cc72a08 100644
--- a/main.go
+++ b/main.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"embed"
 	"log/slog"
 	"os"
 	"os/signal"
@@ -10,6 +11,9 @@ import (
 	"github.com/joho/godotenv"
 )
 
+//go:embed migrations/*.sql
+var migrations embed.FS
+
 func main() {
 	godotenv.Load()
 
@@ -17,7 +21,7 @@ func main() {
 	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
 	defer cancel()
 
-	a := app.New(logger)
+	a := app.New(logger, migrations)
 
 	if err := a.Start(ctx); err != nil {
 		logger.Error("failed to start server", slog.Any("error", err))