Hey everyone,

Just sharing a helper function to get you started when trying to connect to a mysql managed cluster on DigitalOcean with Golang.

Before we get into the code you'll need to grab a couple of things from the database dashboard (on DigitalOcean).

  • Open the databases tab
  • Look for the "Connection Details" section
  • Download your ca cert file
  • Copy down your "public network" settings
    • If you're moving this into a cluster you can use the "private network" settings instead
 // initDb creates initialises the connection to mysql func initDb(connectionString string, caCertPath string) (*sql.DB, error) {  	log.Infof("initialising db connection")  	// Prepare ssl if required: https://stackoverflow.com/a/54189333/522859 	if caCertPath != "" {  		log.Infof("Loading the ca-cert: %v", caCertPath)  		// Load the CA cert 		certBytes, err := ioutil.ReadFile(caCertPath) 		if err != nil { 			log.Fatal("unable to read in the cert file", err) 		}  		caCertPool := x509.NewCertPool() 		if ok := caCertPool.AppendCertsFromPEM(certBytes); !ok { 			log.Fatal("failed-to-parse-sql-ca", err) 		}  		tlsConfig := &tls.Config{ 			InsecureSkipVerify: false, 			RootCAs:            caCertPool, 		}  		mysql.RegisterTLSConfig("bbs-tls", tlsConfig) 	}  	var sqlDb, err = sql.Open("mysql", connectionString) 	if err != nil { 		return nil, fmt.Errorf("failed to connect to the database: %v", err) 	}  	// Ensure that the database can be reached 	err = sqlDb.Ping() 	if err != nil { 		return nil, fmt.Errorf("error on opening database connection: %s", err.Error()) 	}  	return sqlDb, nil }

A couple of things to note in the helper above.

  1. You'll need to provide the path to your downloaded ca-cert as the second argument
  2. Your connection string will need to look something like the following: USERNAME:PASSWORD@tcp(HOST_NAME:PORT_NUMBER)/DB_NAME

Note that the "tcp(...)" bit is required, see the following post for more info: https://whatibroke.com/2021/11/27/failed-to-connect-to-the-database-default-addr-for-network-unknown-mysql-and-golang/

Depending on which version of the mysql driver you're using you may also need to revert to the legacy auth mechanism: https://docs.digitalocean.com/products/databases/mysql/resources/troubleshoot-connections/#authentication

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