http_transport.go

// Copyright 2022-2024 Sauce Labs Inc., all rights reserved.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.

package forwarder

import (
	"crypto/tls"
	"net/http"
	"time"
)

type HTTPTransportConfig struct {
	DialConfig

	TLSClientConfig

	// MaxIdleConns controls the maximum number of idle (keep-alive)
	// connections across all hosts. Zero means no limit.
	MaxIdleConns int

	// MaxIdleConnsPerHost, if non-zero, controls the maximum idle
	// (keep-alive) connections to keep per-host. If zero,
	// DefaultMaxIdleConnsPerHost is used.
	MaxIdleConnsPerHost int

	// MaxConnsPerHost optionally limits the total number of
	// connections per host, including connections in the dialing,
	// active, and idle states. On limit violation, dials will block.
	//
	// Zero means no limit.
	MaxConnsPerHost int

	// IdleConnTimeout is the maximum amount of time an idle
	// (keep-alive) connection will remain idle before closing
	// itself.
	// Zero means no limit.
	IdleConnTimeout time.Duration

	// ResponseHeaderTimeout, if non-zero, specifies the amount of
	// time to wait for a server's response headers after fully
	// writing the request (including its body, if any). This
	// time does not include the time to read the response body.
	ResponseHeaderTimeout time.Duration

	// ExpectContinueTimeout, if non-zero, specifies the amount of
	// time to wait for a server's first response headers after fully
	// writing the request headers if the request has an
	// "Expect: 100-continue" header. Zero means no timeout and
	// causes the body to be sent immediately, without
	// waiting for the server to approve.
	// This time does not include the time to send the request header.
	ExpectContinueTimeout time.Duration
}

func DefaultHTTPTransportConfig() *HTTPTransportConfig {
	return &HTTPTransportConfig{
		DialConfig:            *DefaultDialConfig(),
		TLSClientConfig:       *DefaultTLSClientConfig(),
		IdleConnTimeout:       90 * time.Second,
		ExpectContinueTimeout: 1 * time.Second,
		MaxIdleConnsPerHost:   512,
	}
}

func NewHTTPTransport(cfg *HTTPTransportConfig) (*http.Transport, error) {
	tlsCfg := new(tls.Config)
	if err := cfg.ConfigureTLSConfig(tlsCfg); err != nil {
		return nil, err
	}

	return &http.Transport{
		Proxy:                 nil,
		DialContext:           NewDialer(&cfg.DialConfig).DialContext,
		TLSClientConfig:       tlsCfg,
		TLSHandshakeTimeout:   cfg.TLSClientConfig.HandshakeTimeout,
		MaxIdleConns:          cfg.MaxIdleConns,
		MaxIdleConnsPerHost:   cfg.MaxIdleConnsPerHost,
		MaxConnsPerHost:       cfg.MaxConnsPerHost,
		IdleConnTimeout:       cfg.IdleConnTimeout,
		ResponseHeaderTimeout: cfg.ResponseHeaderTimeout,
		ExpectContinueTimeout: cfg.ExpectContinueTimeout,

		ForceAttemptHTTP2: true,
		ReadBufferSize:    32 * 1024,
		WriteBufferSize:   32 * 1024,
	}, nil
}