grafana/pkg/tsdb/grafana-postgresql-datasource/proxy.go

package postgres

import (
	"context"
	"net"
	"time"

	"github.com/lib/pq"
	"golang.org/x/net/proxy"
)

// we wrap the proxy.Dialer to become dialer that the postgres module accepts
func newPostgresProxyDialer(dialer proxy.Dialer) pq.Dialer {
	return &postgresProxyDialer{d: dialer}
}

var _ pq.Dialer = (&postgresProxyDialer{})

// postgresProxyDialer implements the postgres dialer using a proxy dialer, as their functions differ slightly
type postgresProxyDialer struct {
	d proxy.Dialer
}

// Dial uses the normal proxy dial function with the updated dialer
func (p *postgresProxyDialer) Dial(network, addr string) (c net.Conn, err error) {
	return p.d.Dial(network, addr)
}

// DialTimeout uses the normal postgres dial timeout function with the updated dialer
func (p *postgresProxyDialer) DialTimeout(network, address string, timeout time.Duration) (net.Conn, error) {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	defer cancel()

	return p.d.(proxy.ContextDialer).DialContext(ctx, network, address)
}

type PgxDialFunc = func(ctx context.Context, network string, address string) (net.Conn, error)

func newPgxDialFunc(dialer proxy.Dialer) PgxDialFunc {
	return func(ctx context.Context, network string, addr string) (net.Conn, error) {
		return dialer.Dial(network, addr)
	}
}