Added proper db migrations

server/app/database.go

@@ -1,44 +0,0 @@
-package app
-
-import "database/sql"
-
-func initializeDb(databaseUrl string) *sql.DB {
-	db, err := sql.Open("sqlite3", databaseUrl)
-
-	if err != nil {
-		panic(err)
-	}
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS sensor_values (
-		timestamp INTEGER NOT NULL,
-		sensor TEXT NOT NULL,
-		value REAL NOT NULL
-	);`)
-
-	if err != nil {
-		panic(err)
-	}
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS sensor_config (
-		sensor TEXT NOT NULL,
-		key TEXT NOT NULL,
-		value REAL NOT NULL,
-		PRIMARY KEY (sensor, key)
-	);`)
-
-	if err != nil {
-		panic(err)
-	}
-
-	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS sessions (
-		id TEXT NOT NULL,
-		expires_at INTEGER NOT NULL,
-		PRIMARY KEY (id)
-	);`)
-
-	if err != nil {
-		panic(err)
-	}
-
-	return db
-}

server/app/server.go

@@ -2,6 +2,7 @@ package app
 
 import (
 	"basic-sensor-receiver/config"
+	"basic-sensor-receiver/database"
 	"basic-sensor-receiver/services"
 	"database/sql"
 )
@@ -15,7 +16,14 @@ type Server struct {
 func InitializeServer() *Server {
 	server := Server{}
 	server.Config = config.LoadConfig()
-	server.DB = initializeDb(server.Config.DatabaseUrl)
+
+	db, err := database.Initialize(server.Config.DatabaseUrl)
+
+	if err != nil {
+		panic(err)
+	}
+
+	server.DB = db
 
 	ctx := services.Context{DB: server.DB, Config: server.Config}
 

server/database/database.go

@@ -0,0 +1,52 @@
+package database
+
+import (
+	"database/sql"
+	"fmt"
+	"time"
+)
+
+func Initialize(databaseUrl string) (*sql.DB, error) {
+	db, err := sql.Open("sqlite3", databaseUrl)
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to open database connection: %w", err)
+	}
+
+	_, err = db.Exec(`CREATE TABLE IF NOT EXISTS migrations (
+		id TEXT NOT NULL,
+		run_at INTEGER NOT NULL
+	);`)
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to initialize migrations table: %w", err)
+	}
+
+	pendingMigrations, err := getPendingMigrations(db)
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to get pending migrations: %w", err)
+	}
+
+	for _, migrationId := range pendingMigrations {
+		migrationSource, err := getMigrationContent(migrationId)
+
+		if err != nil {
+			return nil, err
+		}
+
+		_, err = db.Exec(migrationSource)
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to run migration %s: %w", migrationId, err)
+		}
+
+		_, err = db.Exec("INSERT INTO migrations (id, run_at) VALUES (?, ?)", migrationId, time.Now().Unix())
+
+		if err != nil {
+			return nil, fmt.Errorf("failed to store run migration: %w", err)
+		}
+	}
+
+	return db, nil
+}

server/database/migrations.go

@@ -0,0 +1,100 @@
+package database
+
+import (
+	"database/sql"
+	"embed"
+	"fmt"
+	"io/fs"
+	"sort"
+	"strings"
+)
+
+//go:embed migrations/*.sql
+var migrationStorage embed.FS
+
+func getAppliedMigrationsSet(db *sql.DB) (map[string]bool, error) {
+	set := make(map[string]bool)
+
+	rows, err := db.Query("SELECT id FROM migrations")
+
+	if err != nil {
+		return nil, err
+	}
+
+	defer rows.Close()
+
+	for rows.Next() {
+		var id string
+
+		err := rows.Scan(&id)
+		if err != nil {
+			return nil, err
+		}
+
+		set[id] = true
+	}
+
+	err = rows.Err()
+	if err != nil {
+		return nil, err
+	}
+
+	return set, nil
+}
+
+func getMigrations() ([]string, error) {
+	var items []string
+
+	entries, err := migrationStorage.ReadDir("migrations")
+	if err != nil {
+		return nil, err
+	}
+
+	for _, entry := range entries {
+		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".sql") {
+			items = append(items, strings.TrimSuffix(entry.Name(), ".sql"))
+		}
+	}
+
+	if err != nil {
+		return nil, err
+	}
+
+	sort.Strings(items)
+
+	return items, nil
+}
+
+func getMigrationContent(id string) (string, error) {
+	content, err := fs.ReadFile(migrationStorage, "migrations/"+id+".sql")
+
+	if err != nil {
+		return "", err
+	}
+
+	return string(content), nil
+}
+
+func getPendingMigrations(db *sql.DB) ([]string, error) {
+	var migrationsToRun []string
+
+	migrationSet, err := getAppliedMigrationsSet(db)
+
+	if err != nil {
+		return nil, err
+	}
+
+	storedMigrations, err := getMigrations()
+
+	if err != nil {
+		return nil, fmt.Errorf("failed to load stored migrations: %w", err)
+	}
+
+	for _, storedMigration := range storedMigrations {
+		if !migrationSet[storedMigration] {
+			migrationsToRun = append(migrationsToRun, storedMigration)
+		}
+	}
+
+	return migrationsToRun, nil
+}

server/database/migrations/1661277568662_initial.sql

@@ -0,0 +1,18 @@
+CREATE TABLE IF NOT EXISTS sensor_values (
+	timestamp INTEGER NOT NULL,
+	sensor TEXT NOT NULL,
+	value REAL NOT NULL
+);
+
+CREATE TABLE IF NOT EXISTS sensor_config (
+	sensor TEXT NOT NULL,
+	key TEXT NOT NULL,
+	value REAL NOT NULL,
+	PRIMARY KEY (sensor, key)
+);
+
+CREATE TABLE IF NOT EXISTS sessions (
+	id TEXT NOT NULL,
+	expires_at INTEGER NOT NULL,
+	PRIMARY KEY (id)
+);