87 lines
1.9 KiB
Go
87 lines
1.9 KiB
Go
package proxytransport
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import (
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"context"
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"fmt"
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"net"
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"net/http"
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"sync"
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"time"
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)
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var dnsCache sync.Map
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func init() {
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go func() {
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for {
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time.Sleep(5 * time.Minute)
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dnsCache.Range(func(key, _ any) bool {
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dnsCache.Delete(key)
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return true
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})
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}
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}()
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}
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func newTransport(dialTimeout, tlsTimeout, headerTimeout time.Duration) *http.Transport {
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return &http.Transport{
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MaxIdleConns: 100,
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MaxIdleConnsPerHost: 10,
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IdleConnTimeout: 90 * time.Second,
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TLSHandshakeTimeout: tlsTimeout,
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ResponseHeaderTimeout: headerTimeout,
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ExpectContinueTimeout: 1 * time.Second,
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DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
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host, port, err := net.SplitHostPort(addr)
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if err != nil {
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return nil, err
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}
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ips, ok := dnsCache.Load(host)
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if !ok {
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resolved, err := net.DefaultResolver.LookupIPAddr(ctx, host)
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if err != nil {
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return nil, fmt.Errorf("proxy dns lookup: %w", err)
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}
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dnsCache.Store(host, resolved)
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ips = resolved
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}
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return dialIPs(ctx, network, host, port, ips.([]net.IPAddr), dialTimeout)
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},
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}
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}
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func dialIPs(ctx context.Context, network, host, port string, ips []net.IPAddr, timeout time.Duration) (net.Conn, error) {
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var firstErr error
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for _, ip := range ips {
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select {
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case <-ctx.Done():
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return nil, ctx.Err()
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default:
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}
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dialer := net.Dialer{Timeout: timeout}
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conn, err := dialer.DialContext(ctx, network, net.JoinHostPort(ip.String(), port))
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if err == nil {
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return conn, nil
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}
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if firstErr == nil {
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firstErr = err
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}
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}
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return nil, fmt.Errorf("proxy dial %s: %w", host, firstErr)
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}
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func NewClient() *http.Client {
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return &http.Client{
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Transport: newTransport(10*time.Second, 10*time.Second, 30*time.Second),
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Timeout: 60 * time.Second,
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}
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}
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func NewStreamingClient() *http.Client {
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return &http.Client{
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Transport: newTransport(10*time.Second, 10*time.Second, 15*time.Second),
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}
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}
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