feature: add --proxy to net/http

This adds a new --proxy flag,
that alows to specify a proxy to use like in curl.

One could instead fix the env var mechanism
which does not work as reported
(see codesenberg#78).

But this is maybe more straigthforward and more user friendly.

args_parser.go

@@ -33,6 +33,7 @@ type kingpinParser struct {
 	method            string
 	body              string
 	bodyFilePath      string
+	proxy             string
 	stream            bool
 	certPath          string
 	keyPath           string
@@ -56,6 +57,7 @@ func newKingpinParser() argsParser {
 		method:       "GET",
 		body:         "",
 		bodyFilePath: "",
+		proxy:        "",
 		stream:       false,
 		certPath:     "",
 		keyPath:      "",
@@ -151,6 +153,10 @@ func newKingpinParser() argsParser {
 		}).
 		Bool()
 
+	app.Flag("proxy", "Use the specified HTTP proxy").
+		Default("").
+		StringVar(&kparser.proxy)
+
 	app.Flag(
 		"print", "Specifies what to output. Comma-separated list of values"+
 			" 'intro' (short: 'i'), 'progress' (short: 'p'),"+
@@ -222,6 +228,7 @@ func (k *kingpinParser) parse(args []string) (config, error) {
 		method:            k.method,
 		body:              k.body,
 		bodyFilePath:      k.bodyFilePath,
+		proxy:             k.proxy,
 		stream:            k.stream,
 		keyPath:           k.keyPath,
 		certPath:          k.certPath,

args_parser_test.go

@@ -403,6 +403,35 @@ func TestArgsParsing(t *testing.T) {
 				format:        knownFormat("plain-text"),
 			},
 		},
+		{
+			[][]string{
+				{
+					programName,
+					"--http2",
+					"--proxy", "http://proxyHost:proxyPort",
+					"https://somehost.somedomain",
+				},
+				{
+					programName,
+					"--http2",
+					"--proxy=http://proxyHost:proxyPort",
+					"https://somehost.somedomain",
+				},
+			},
+			config{
+				numConns:      defaultNumberOfConns,
+				timeout:       defaultTimeout,
+				headers:       new(headersList),
+				method:        "GET",
+				url:           "https://somehost.somedomain:443",
+				clientType:    nhttp2,
+				printIntro:    true,
+				printProgress: true,
+				printResult:   true,
+				format:        knownFormat("plain-text"),
+				proxy:         "http://proxyHost:proxyPort",
+			},
+		},
 		{
 			[][]string{
 				{

bombardier.go

@@ -136,6 +136,7 @@ func newBombardier(c config) (*bombardier, error) {
 		headers:      c.headers,
 		url:          c.url,
 		method:       c.method,
+		proxy:        c.proxy,
 		body:         pbody,
 		bodProd:      bsp,
 		bytesRead:    &b.bytesRead,

clients.go

@@ -27,8 +27,8 @@ type clientOpts struct {
 	tlsConfig         *tls.Config
 	disableKeepAlives bool
 
-	headers     *headersList
-	url, method string
+	headers            *headersList
+	url, method, proxy string
 
 	body    *string
 	bodProd bodyStreamProducer
@@ -132,11 +132,19 @@ type httpClient struct {
 
 func newHTTPClient(opts *clientOpts) client {
 	c := new(httpClient)
+
 	tr := &http.Transport{
 		TLSClientConfig:     opts.tlsConfig,
 		MaxIdleConnsPerHost: int(opts.maxConns),
 		DisableKeepAlives:   opts.disableKeepAlives,
 	}
+
+	if opts.proxy != "" {
+		url_i := url.URL{}
+		url_proxy, _ := url_i.Parse(opts.proxy)
+		tr.Proxy = http.ProxyURL(url_proxy)
+	}
+
 	tr.DialContext = httpDialContextFunc(opts.bytesRead, opts.bytesWritten)
 	if opts.HTTP2 {
 		_ = http2.ConfigureTransport(tr)

config.go

@@ -8,15 +8,15 @@ import (
 )
 
 type config struct {
-	numConns                       uint64
-	numReqs                        *uint64
-	disableKeepAlives         bool
-	duration                       *time.Duration
-	url, method, certPath, keyPath string
-	body, bodyFilePath             string
-	stream                         bool
-	headers                        *headersList
-	timeout                        time.Duration
+	numConns                              uint64
+	numReqs                               *uint64
+	disableKeepAlives                     bool
+	duration                              *time.Duration
+	url, method, certPath, keyPath, proxy string
+	body, bodyFilePath                    string
+	stream                                bool
+	headers                               *headersList
+	timeout                               time.Duration
 	// TODO(codesenberg): printLatencies should probably be
 	// re(named&maked) into printPercentiles or even let
 	// users provide their own percentiles and not just