An HTTP client creator for Golang

httpclient.go

package httpclient

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

// Options includes common Client configurations that need to be tuned.
type Options struct {
	TotalTimeout          time.Duration
	ConnectTimeout        time.Duration
	KeepAliveTimeout      time.Duration
	MaxIdleConns          int
	MaxIdleConnsPerHost   int
	IdleConnTimeout       time.Duration
	TLSHandshakeTimeout   time.Duration
	ResponseHeaderTimeout time.Duration
	ExpectContinueTimeout time.Duration
}

func (o *Options) totalTimeout() time.Duration {
	if o == nil {
		return 30 * time.Second
	}
	return o.TotalTimeout
}

func (o *Options) connectTimeout() time.Duration {
	if o == nil {
		return 30 * time.Second
	}
	return o.ConnectTimeout
}

func (o *Options) keepAliveTimeout() time.Duration {
	if o == nil {
		return 30 * time.Second
	}
	return o.KeepAliveTimeout
}

func (o *Options) maxIdleConns() int {
	if o == nil {
		return 100
	}
	return o.MaxIdleConns
}

func (o *Options) maxIdleConnsPerHost() int {
	if o == nil {
		return 0
	}
	return o.MaxIdleConnsPerHost
}

func (o *Options) idleConnTimeout() time.Duration {
	if o == nil {
		return 90 * time.Second
	}
	return o.IdleConnTimeout
}

func (o *Options) tlsHandshakeTimeout() time.Duration {
	if o == nil {
		return 10 * time.Second
	}
	return o.TLSHandshakeTimeout
}

func (o *Options) responseHeaderTimeout() time.Duration {
	if o == nil {
		return 0
	}
	return o.ResponseHeaderTimeout
}

func (o *Options) expectContinueTimeout() time.Duration {
	if o == nil {
		return 1 * time.Second
	}
	return o.ExpectContinueTimeout
}

// New creates a Client with the given options. If nil is provided, the created
// Client will behave like the default Client with Timeout set to 30s.
func New(opts *Options) *http.Client {
	transport := &http.Transport{
		Proxy: http.ProxyFromEnvironment,
		DialContext: (&net.Dialer{
			Timeout:   opts.connectTimeout(),
			KeepAlive: opts.keepAliveTimeout(),
			DualStack: true,
		}).DialContext,
		MaxIdleConns:          opts.maxIdleConns(),
		MaxIdleConnsPerHost:   opts.maxIdleConnsPerHost(),
		IdleConnTimeout:       opts.idleConnTimeout(),
		TLSHandshakeTimeout:   opts.tlsHandshakeTimeout(),
		ResponseHeaderTimeout: opts.responseHeaderTimeout(),
		ExpectContinueTimeout: opts.expectContinueTimeout(),
	}
	return &http.Client{
		Timeout:   opts.totalTimeout(),
		Transport: transport,
	}
}