Plugins: Add sql support for the secure socks proxy (#64630)

pkg/tsdb/mysql/proxy.go

@@ -0,0 +1,57 @@
+package mysql
+
+import (
+	"context"
+	"net"
+
+	"github.com/go-sql-driver/mysql"
+	iproxy "github.com/grafana/grafana/pkg/infra/proxy"
+	"github.com/grafana/grafana/pkg/setting"
+	"github.com/grafana/grafana/pkg/util"
+	"golang.org/x/net/proxy"
+)
+
+// registerProxyDialerContext registers a new dialer context to be used by mysql when the proxy network is
+// specified in the connection string
+func registerProxyDialerContext(settings *setting.SecureSocksDSProxySettings, protocol, cnnstr string) (string, error) {
+	// the dialer contains the true network used behind the scenes
+	dialer, err := getProxyDialerContext(settings, protocol)
+	if err != nil {
+		return "", err
+	}
+
+	// the dialer context can be updated everytime the datasource is updated
+	// have a unique network per connection string
+	hash, err := util.Md5SumString(cnnstr)
+	if err != nil {
+		return "", err
+	}
+	network := "proxy-" + hash
+	mysql.RegisterDialContext(network, dialer.DialContext)
+
+	return network, nil
+}
+
+// mySQLContextDialer turns a golang proxy driver into a MySQL proxy driver
+type mySQLContextDialer struct {
+	dialer  proxy.ContextDialer
+	network string
+}
+
+// getProxyDialerContext returns a context dialer that will send the request through to the secure socks proxy
+func getProxyDialerContext(cfg *setting.SecureSocksDSProxySettings, actualNetwork string) (*mySQLContextDialer, error) {
+	dialer, err := iproxy.NewSecureSocksProxyContextDialer(cfg)
+	if err != nil {
+		return nil, err
+	}
+	contextDialer, ok := dialer.(proxy.ContextDialer)
+	if !ok {
+		return nil, err
+	}
+	return &mySQLContextDialer{dialer: contextDialer, network: actualNetwork}, nil
+}
+
+// DialContext implements the MySQL requirements for a proxy driver, and uses the underlying golang proxy driver with the assigned network
+func (d *mySQLContextDialer) DialContext(ctx context.Context, addr string) (net.Conn, error) {
+	return d.dialer.DialContext(ctx, d.network, addr)
+}