feat(db): migrate from MySQL to PostgreSQL

Replace MySQL driver with pgx/v5 and pgxpool:
- Update sqlc to use postgresql engine
- Convert query.sql to PostgreSQL syntax ($1 params, CASE WHEN,
  ANY() arrays)
- Replace sql.DB with pgxpool.Pool throughout
- Change nullable types from sql.Null* to pgtype.*
- Update ID types from uint32 to int64 for PostgreSQL compatibility
- Delete MySQL-specific dynamic_connect.go
- Add opentelemetry.gowrap template for tracing

ntpdb/dbconn.go

@@ -1,85 +1,15 @@
 package ntpdb
 
+//go:generate go tool github.com/hexdigest/gowrap/cmd/gowrap gen -t ./opentelemetry.gowrap -g -i QuerierTx -p . -o otel.go
+
 import (
 	"context"
-	"database/sql"
-	"database/sql/driver"
-	"fmt"
-	"os"
-	"time"
 
-	"github.com/go-sql-driver/mysql"
-	"go.ntppool.org/common/logger"
-	"gopkg.in/yaml.v3"
+	"github.com/jackc/pgx/v5/pgxpool"
+	"go.ntppool.org/common/database/pgdb"
 )
 
-type Config struct {
-	MySQL DBConfig `yaml:"mysql"`
-}
-
-type DBConfig struct {
-	DSN  string `default:"" flag:"dsn" usage:"Database DSN"`
-	User string `default:"" flag:"user"`
-	Pass string `default:"" flag:"pass"`
-}
-
-func OpenDB(ctx context.Context, configFile string) (*sql.DB, error) {
-	log := logger.FromContext(ctx)
-
-	dbconn := sql.OpenDB(Driver{CreateConnectorFunc: createConnector(ctx, configFile)})
-
-	dbconn.SetConnMaxLifetime(time.Minute * 3)
-	dbconn.SetMaxOpenConns(8)
-	dbconn.SetMaxIdleConns(3)
-
-	err := dbconn.Ping()
-	if err != nil {
-		log.DebugContext(ctx, "could not connect to database: %s", "err", err)
-		return nil, err
-	}
-
-	return dbconn, nil
-}
-
-func createConnector(ctx context.Context, configFile string) CreateConnectorFunc {
-	log := logger.FromContext(ctx)
-	return func() (driver.Connector, error) {
-		log.DebugContext(ctx, "opening db config file", "filename", configFile)
-
-		dbFile, err := os.Open(configFile)
-		if err != nil {
-			return nil, err
-		}
-
-		dec := yaml.NewDecoder(dbFile)
-
-		cfg := Config{}
-
-		err = dec.Decode(&cfg)
-		if err != nil {
-			return nil, err
-		}
-
-		// log.Printf("db cfg: %+v", cfg)
-
-		dsn := cfg.MySQL.DSN
-		if len(dsn) == 0 {
-			return nil, fmt.Errorf("--database.dsn flag or DATABASE_DSN environment variable required")
-		}
-
-		dbcfg, err := mysql.ParseDSN(dsn)
-		if err != nil {
-			return nil, err
-		}
-
-		if user := cfg.MySQL.User; len(user) > 0 {
-			dbcfg.User = user
-		}
-
-		if pass := cfg.MySQL.Pass; len(pass) > 0 {
-			dbcfg.Passwd = pass
-		}
-
-		return mysql.NewConnector(dbcfg)
-	}
+// OpenDB opens a PostgreSQL connection pool using the specified config file
+func OpenDB(ctx context.Context, configFile string) (*pgxpool.Pool, error) {
+	return pgdb.OpenPoolWithConfigFile(ctx, configFile)
 }