func initTCPConnectionPool()

in analytics/server.go [261:290]
24 lines of code
3 McCabe index (conditional complexity)

func initTCPConnectionPool() (*sql.DB, error) {
	// [START cloud_sql_postgres_databasesql_create_tcp]
	var (
		dbUser    = mustGetenv("DB_USER") // e.g. 'my-db-user'
		dbPwd     = mustGetenv("DB_PASS") // e.g. 'my-db-password'
		dbTCPHost = mustGetenv("DB_HOST") // e.g. '127.0.0.1' ('172.17.0.1' if deployed to GAE Flex)
		dbPort    = mustGetenv("DB_PORT") // e.g. '5432'
		dbName    = mustGetenv("DB_NAME") // e.g. 'my-database'
	)

	dbURI := fmt.Sprintf("host=%s user=%s password=%s port=%s database=%s", dbTCPHost, dbUser, dbPwd, dbPort, dbName)

	dbRootCert := os.Getenv("DB_ROOT_CERT") // e.g., '/path/to/my/server-ca.pem'
	if dbRootCert != "" {
		var (
			dbCert = mustGetenv("DB_CERT") // e.g. '/path/to/my/client-cert.pem'
			dbKey  = mustGetenv("DB_KEY")  // e.g. '/path/to/my/client-key.pem'
		)
		dbURI += fmt.Sprintf(" sslmode=require sslrootcert=%s sslcert=%s sslkey=%s", dbRootCert, dbCert, dbKey)
	}

	dbPool, err := sql.Open("pgx", dbURI)
	if err != nil {
		return nil, fmt.Errorf("sql.Open: %v", err)
	}

	configureConnectionPool(dbPool)

	return dbPool, nil
}