mysql

mysql

This package registers a MySQL and MariaDB database/sql driver as mysql and selects its implementation at build time:

import "github.com/shibukawa/tinygodriver/database/sql/mysql"

db, err := mysql.Open("user:pass@tcp(127.0.0.1:3306)/app")

The DSN syntax, driver name and database/sql behavior are the same on both backends, because the TinyGo backend is a fork of the standard-Go one. It exists because TinyGo's net.Conn cannot supply a descriptor for connection health checks or for an in-band TLS upgrade; see tinygomysql/README.md for the details and for the MPL-2.0 notice that covers that directory.

TLS

tls=true, tls=skip-verify and tls=preferred work on both backends. For a private CA, register the trust settings under a name and use it as tls=<name>:

ca, err := os.ReadFile("/etc/ssl/db-ca.pem")
if err != nil {
	log.Fatal(err)
}
err = mysql.RegisterTLSConfig("db", &https.Config{
	RootCAs:     [][]byte{ca},
	RootCAsOnly: true,
})
// ...
db, err := mysql.Open("user:pass@tcp(db.internal:3306)/app?tls=db")

RegisterTLSConfig takes an https.Config on both backends, so this code is portable; the standard-Go backend converts it to a crypto/tls.Config internally. PEM bytes are used rather than crypto/tls types because TinyGo builds must not link crypto/tls.

On TinyGo the handshake runs on the OS TLS stack through the https.DialPlain / https.Upgrade seam — Secure Transport on macOS, mbedTLS on Linux, Schannel on Windows. macOS caps at TLS 1.2 there, because Apple never added 1.3 to Secure Transport; build with -tags darwinstarttlswith13 for 1.3. Client certificates are unsupported on macOS.

TinyGo notes

Use the threads scheduler, which is the default on desktop targets. Under the cooperative scheduler (-scheduler=tasks) a blocking socket call holds the whole runtime, so the driver's cancellation watcher never runs and QueryContext ignores its deadline without reporting an error. Measured: a SELECT SLEEP(5) with a 500 ms deadline returned after the full five seconds with a nil error.

Blank-import netdev, as with any TinyGo program that uses the network:

import _ "github.com/shibukawa/tinygodriver/netdev"

Unix sockets and IPv6 are unavailable, so connect over TCP to an IPv4 host. The DSN timeout= parameter has no effect, because TinyGo's net.Dialer ignores both its Timeout field and the context. readTimeout, writeTimeout and query-level deadlines all work.