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net/http package
GoConference 2017 Spring
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kaneshin (Shintaro Kaneko)
- CTO of Eureka, Inc.
- Twitter: @kaneshin0120
- Gopher, Vimmer, Photographer, Mathematician
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'BDFCPPLΛར༻ͨ͠
࿀Ѫɾࠗ׆ϚονϯάαʔϏε
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Learning golang from code
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Today's special
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http/httptest
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net/http/httptest
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http/httptest
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
http://blog.kaneshin.co/entry/2016/12/02/200108
net/http/httptest.Server
net/http/httptest.ResponseRecorder
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net/http/httptest
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.ResponseWriter
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
var handler = func(w http.ResponseWriter, r *http.Request) {
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
var handler = func(w http.ResponseWriter, r *http.Request) {
w.Write([]byte("Hello world!"))
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
var handler = func(w http.ResponseWriter, r *http.Request) {
w.WriteHeader(http.StatusCreated)
w.Write([]byte("Hello world!"))
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
var handler = func(w http.ResponseWriter, r *http.Request) {
w.Header("X-Foo", "bar")
w.WriteHeader(http.StatusCreated)
w.Write([]byte("Hello world!"))
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
type ResponseWriter interface {
// Changing the header map after a call to WriteHeader (or
// Write) has no effect unless the modified headers are trailers.
Header() Header
Write([]byte) (int, error)
// If WriteHeader is not called explicitly, the first call to Write
// will trigger an implicit WriteHeader(http.StatusOK).
WriteHeader(int)
}
var handler = func(w http.ResponseWriter, r *http.Request) {
w.Header("X-Foo", "bar")
w.WriteHeader(http.StatusCreated)
w.Write([]byte("Hello world!"))
// ❌ w.WriteHeader(http.StatusBadRequest) after a call to Write
// ❌ w.Header("X-Foo", "qux") after a call to WriteHeader
}
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net/http.ResponseWriter
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.Client
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
/// package http
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
/// package http
func Get(url string) (resp *Response, err error) {
return DefaultClient.Get(url)
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
/// package http
func Get(url string) (resp *Response, err error) {
return DefaultClient.Get(url)
}
var DefaultClient = &Client{}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
/// package http
func Get(url string) (resp *Response, err error) {
return DefaultClient.Get(url)
}
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
/// package http
var DefaultTransport RoundTripper = &Transport{
Proxy: ProxyFromEnvironment,
DialContext: (&net.Dialer{
Timeout: 30 * time.Second,
KeepAlive: 30 * time.Second,
DualStack: true,
}).DialContext,
MaxIdleConns: 100,
IdleConnTimeout: 90 * time.Second,
TLSHandshakeTimeout: 10 * time.Second,
ExpectContinueTimeout: 1 * time.Second,
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
// A Timeout of zero means no timeout.
Timeout time.Duration
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
// A Timeout of zero means no timeout.
Timeout time.Duration
}
func init() {
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
// A Timeout of zero means no timeout.
Timeout time.Duration
}
func init() {
http.DefaultClient.Timeout = 30 * time.Second
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
// A Client is an HTTP client. Its zero value (DefaultClient) is a
// usable client that uses DefaultTransport.
//
// The Client's Transport typically has internal state (cached TCP
// connections), so Clients should be reused instead of created as
// needed. Clients are safe for concurrent use by multiple goroutines.
// ...
var DefaultClient = &Client{}
type Client struct {
Transport RoundTripper
CheckRedirect func(req *Request, via []*Request) error
Jar CookieJar
// A Timeout of zero means no timeout.
Timeout time.Duration
}
func init() {
http.DefaultClient.Timeout = 30 * time.Second
// Modify if needed.
http.DefaultTransport = &http.Transport{
// ...
}
}
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net/http.Client
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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Others
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net/http.Response.Body.Close()
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.Response.Body.Close()
var sleepHandler = func(w http.ResponseWriter, r *http.Request) {
time.Sleep(time.Hour)
w.Write([]byte("Hello world!"))
}
func main() {
s := httptest.NewServer(http.HandlerFunc(sleepHandler))
defer s.Close()
resp, err := http.Get(s.URL)
if err != nil {
return
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
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net/http.Constants
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Settable net/http.Client
type FooClient struct {
HTTPClient *http.Client
}
/// OR
type FooClient struct {
httpClient *http.Client
}
func NewFooClient(httpClient *http.Client) FooClient {
return FooClient{
httpClient: httpClient,
}
}
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Summaries
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Summaries
• net/http/httptest
• net/http.ResponseWriter
• net/http.Client
• net/http.Response.Body.Close()
• net/http.Constants
• Settable net/http.Client
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Thank you
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