tsweb: remove JSONHandlerFunc

It's unused and we've decided it's not what we want.

Change-Id: I425a0104e8869630b498a0adfd0f455876d6f92b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2022-05-03 21:42:24 -07:00 committed by Brad Fitzpatrick
parent 7ee3068f9d
commit 2d1849a7b9
4 changed files with 53 additions and 464 deletions

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@ -1,157 +0,0 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tsweb
import (
"bytes"
"compress/gzip"
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"strconv"
"strings"
"sync"
"go4.org/mem"
)
type response struct {
Status string `json:"status"`
Error string `json:"error,omitempty"`
Data any `json:"data,omitempty"`
}
// JSONHandlerFunc is an HTTP ReturnHandler that writes JSON responses to the client.
//
// Return a HTTPError to show an error message, otherwise JSONHandlerFunc will
// only report "internal server error" to the user with status code 500.
type JSONHandlerFunc func(r *http.Request) (status int, data any, err error)
// ServeHTTPReturn implements the ReturnHandler interface.
//
// Use the following code to unmarshal the request body
//
// body := new(DataType)
// if err := json.NewDecoder(r.Body).Decode(body); err != nil {
// return http.StatusBadRequest, nil, err
// }
//
// See jsonhandler_test.go for examples.
func (fn JSONHandlerFunc) ServeHTTPReturn(w http.ResponseWriter, r *http.Request) error {
w.Header().Set("Content-Type", "application/json")
var resp *response
status, data, err := fn(r)
if err != nil {
if werr, ok := err.(HTTPError); ok {
resp = &response{
Status: "error",
Error: werr.Msg,
Data: data,
}
// Unwrap the HTTPError here because we are communicating with
// the client in this handler. We don't want the wrapping
// ReturnHandler to do it too.
err = werr.Err
if werr.Msg != "" {
err = fmt.Errorf("%s: %w", werr.Msg, err)
}
// take status from the HTTPError to encourage error handling in one location
if status != 0 && status != werr.Code {
err = fmt.Errorf("[unexpected] non-zero status that does not match HTTPError status, status: %d, HTTPError.code: %d: %w", status, werr.Code, err)
}
status = werr.Code
} else {
status = http.StatusInternalServerError
resp = &response{
Status: "error",
Error: "internal server error",
}
}
} else if status == 0 {
status = http.StatusInternalServerError
resp = &response{
Status: "error",
Error: "internal server error",
}
} else if err == nil {
resp = &response{
Status: "success",
Data: data,
}
}
b, jerr := json.Marshal(resp)
if jerr != nil {
w.WriteHeader(http.StatusInternalServerError)
w.Write([]byte(`{"status":"error","error":"json marshal error"}`))
if err != nil {
return fmt.Errorf("%w, and then we could not respond: %v", err, jerr)
}
return jerr
}
if AcceptsEncoding(r, "gzip") {
encb, err := gzipBytes(b)
if err != nil {
return err
}
w.Header().Set("Content-Encoding", "gzip")
w.Header().Set("Content-Length", strconv.Itoa(len(encb)))
w.WriteHeader(status)
w.Write(encb)
} else {
w.Header().Set("Content-Length", strconv.Itoa(len(b)))
w.WriteHeader(status)
w.Write(b)
}
return err
}
var gzWriterPool sync.Pool // of *gzip.Writer
// gzipBytes returns the gzipped encoding of b.
func gzipBytes(b []byte) (zb []byte, err error) {
var buf bytes.Buffer
zw, ok := gzWriterPool.Get().(*gzip.Writer)
if ok {
zw.Reset(&buf)
} else {
zw = gzip.NewWriter(&buf)
}
defer gzWriterPool.Put(zw)
if _, err := zw.Write(b); err != nil {
return nil, err
}
if err := zw.Close(); err != nil {
return nil, err
}
zb = buf.Bytes()
zw.Reset(ioutil.Discard)
return zb, nil
}
// AcceptsEncoding reports whether r accepts the named encoding
// ("gzip", "br", etc).
func AcceptsEncoding(r *http.Request, enc string) bool {
h := r.Header.Get("Accept-Encoding")
if h == "" {
return false
}
if !strings.Contains(h, enc) && !mem.ContainsFold(mem.S(h), mem.S(enc)) {
return false
}
remain := h
for len(remain) > 0 {
var part string
part, remain, _ = strings.Cut(remain, ",")
part = strings.TrimSpace(part)
part, _, _ = strings.Cut(part, ";")
if part == enc {
return true
}
}
return false
}

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@ -1,307 +0,0 @@
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tsweb
import (
"bytes"
"compress/gzip"
"encoding/json"
"fmt"
"io"
"net/http"
"net/http/httptest"
"strings"
"testing"
"github.com/google/go-cmp/cmp"
)
type Data struct {
Name string
Price int
}
type Response struct {
Status string
Error string
Data *Data
}
func TestNewJSONHandler(t *testing.T) {
checkStatus := func(t *testing.T, w *httptest.ResponseRecorder, status string, code int) *Response {
d := &Response{
Data: &Data{},
}
bodyBytes := w.Body.Bytes()
if w.Result().Header.Get("Content-Encoding") == "gzip" {
zr, err := gzip.NewReader(bytes.NewReader(bodyBytes))
if err != nil {
t.Fatalf("gzip read error at start: %v", err)
}
bodyBytes, err = io.ReadAll(zr)
if err != nil {
t.Fatalf("gzip read error: %v", err)
}
}
t.Logf("%s", bodyBytes)
err := json.Unmarshal(bodyBytes, d)
if err != nil {
t.Logf(err.Error())
return nil
}
if d.Status == status {
t.Logf("ok: %s", d.Status)
} else {
t.Fatalf("wrong status: got: %s, want: %s", d.Status, status)
}
if w.Code != code {
t.Fatalf("wrong status code: got: %d, want: %d", w.Code, code)
}
if w.Header().Get("Content-Type") != "application/json" {
t.Fatalf("wrong content type: %s", w.Header().Get("Content-Type"))
}
return d
}
h21 := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return http.StatusOK, nil, nil
})
t.Run("200 simple", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("GET", "/", nil)
h21.ServeHTTPReturn(w, r)
checkStatus(t, w, "success", http.StatusOK)
})
t.Run("403 HTTPError", func(t *testing.T) {
h := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return 0, nil, Error(http.StatusForbidden, "forbidden", nil)
})
w := httptest.NewRecorder()
r := httptest.NewRequest("GET", "/", nil)
h.ServeHTTPReturn(w, r)
checkStatus(t, w, "error", http.StatusForbidden)
})
h22 := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return http.StatusOK, &Data{Name: "tailscale"}, nil
})
t.Run("200 get data", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("GET", "/", nil)
h22.ServeHTTPReturn(w, r)
checkStatus(t, w, "success", http.StatusOK)
})
h31 := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
body := new(Data)
if err := json.NewDecoder(r.Body).Decode(body); err != nil {
return 0, nil, Error(http.StatusBadRequest, err.Error(), err)
}
if body.Name == "" {
return 0, nil, Error(http.StatusBadRequest, "name is empty", nil)
}
return http.StatusOK, nil, nil
})
t.Run("200 post data", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{"Name": "tailscale"}`))
h31.ServeHTTPReturn(w, r)
checkStatus(t, w, "success", http.StatusOK)
})
t.Run("400 bad json", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{`))
h31.ServeHTTPReturn(w, r)
checkStatus(t, w, "error", http.StatusBadRequest)
})
t.Run("400 post data error", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{}`))
h31.ServeHTTPReturn(w, r)
resp := checkStatus(t, w, "error", http.StatusBadRequest)
if resp.Error != "name is empty" {
t.Fatalf("wrong error")
}
})
h32 := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
body := new(Data)
if err := json.NewDecoder(r.Body).Decode(body); err != nil {
return 0, nil, Error(http.StatusBadRequest, err.Error(), err)
}
if body.Name == "root" {
return 0, nil, fmt.Errorf("invalid name")
}
if body.Price == 0 {
return 0, nil, Error(http.StatusBadRequest, "price is empty", nil)
}
return http.StatusOK, &Data{Price: body.Price * 2}, nil
})
t.Run("200 post data", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{"Price": 10}`))
h32.ServeHTTPReturn(w, r)
resp := checkStatus(t, w, "success", http.StatusOK)
t.Log(resp.Data)
if resp.Data.Price != 20 {
t.Fatalf("wrong price: %d %d", resp.Data.Price, 10)
}
})
t.Run("gzipped", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{"Price": 10}`))
r.Header.Set("Accept-Encoding", "gzip")
h32.ServeHTTPReturn(w, r)
res := w.Result()
if ct := res.Header.Get("Content-Encoding"); ct != "gzip" {
t.Fatalf("encoding = %q; want gzip", ct)
}
resp := checkStatus(t, w, "success", http.StatusOK)
t.Log(resp.Data)
if resp.Data.Price != 20 {
t.Fatalf("wrong price: %d %d", resp.Data.Price, 10)
}
})
t.Run("gzipped_400", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{"Price": 10}`))
r.Header.Set("Accept-Encoding", "gzip")
value := []string{"foo", "foo", "foo"}
JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return 400, value, nil
}).ServeHTTPReturn(w, r)
res := w.Result()
if ct := res.Header.Get("Content-Encoding"); ct != "gzip" {
t.Fatalf("encoding = %q; want gzip", ct)
}
if res.StatusCode != 400 {
t.Errorf("Status = %v; want 400", res.StatusCode)
}
})
t.Run("400 post data error", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{}`))
h32.ServeHTTPReturn(w, r)
resp := checkStatus(t, w, "error", http.StatusBadRequest)
if resp.Error != "price is empty" {
t.Fatalf("wrong error")
}
})
t.Run("500 internal server error (unspecified error, not of type HTTPError)", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", strings.NewReader(`{"Name": "root"}`))
h32.ServeHTTPReturn(w, r)
resp := checkStatus(t, w, "error", http.StatusInternalServerError)
if resp.Error != "internal server error" {
t.Fatalf("wrong error")
}
})
t.Run("500 misuse", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", nil)
JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return http.StatusOK, make(chan int), nil
}).ServeHTTPReturn(w, r)
resp := checkStatus(t, w, "error", http.StatusInternalServerError)
if resp.Error != "json marshal error" {
t.Fatalf("wrong error")
}
})
t.Run("500 empty status code", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", nil)
JSONHandlerFunc(func(r *http.Request) (status int, data any, err error) {
return
}).ServeHTTPReturn(w, r)
checkStatus(t, w, "error", http.StatusInternalServerError)
})
t.Run("403 forbidden, status returned by JSONHandlerFunc and HTTPError agree", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", nil)
JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return http.StatusForbidden, nil, Error(http.StatusForbidden, "403 forbidden", nil)
}).ServeHTTPReturn(w, r)
want := &Response{
Status: "error",
Data: &Data{},
Error: "403 forbidden",
}
got := checkStatus(t, w, "error", http.StatusForbidden)
if diff := cmp.Diff(want, got); diff != "" {
t.Fatalf(diff)
}
})
t.Run("403 forbidden, status returned by JSONHandlerFunc and HTTPError do not agree", func(t *testing.T) {
w := httptest.NewRecorder()
r := httptest.NewRequest("POST", "/", nil)
err := JSONHandlerFunc(func(r *http.Request) (int, any, error) {
return http.StatusInternalServerError, nil, Error(http.StatusForbidden, "403 forbidden", nil)
}).ServeHTTPReturn(w, r)
if !strings.HasPrefix(err.Error(), "[unexpected]") {
t.Fatalf("returned error should have `[unexpected]` to note the disagreeing status codes: %v", err)
}
want := &Response{
Status: "error",
Data: &Data{},
Error: "403 forbidden",
}
got := checkStatus(t, w, "error", http.StatusForbidden)
if diff := cmp.Diff(want, got); diff != "" {
t.Fatalf("(-want,+got):\n%s", diff)
}
})
}
func TestAcceptsEncoding(t *testing.T) {
tests := []struct {
in, enc string
want bool
}{
{"", "gzip", false},
{"gzip", "gzip", true},
{"foo,gzip", "gzip", true},
{"foo, gzip", "gzip", true},
{"foo, gzip ", "gzip", true},
{"gzip, foo ", "gzip", true},
{"gzip, foo ", "br", false},
{"gzip, foo ", "fo", false},
{"gzip;q=1.2, foo ", "gzip", true},
{" gzip;q=1.2, foo ", "gzip", true},
}
for i, tt := range tests {
h := make(http.Header)
if tt.in != "" {
h.Set("Accept-Encoding", tt.in)
}
got := AcceptsEncoding(&http.Request{Header: h}, tt.enc)
if got != tt.want {
t.Errorf("%d. got %v; want %v", i, got, tt.want)
}
}
}

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@ -24,6 +24,7 @@
"strings" "strings"
"time" "time"
"go4.org/mem"
"inet.af/netaddr" "inet.af/netaddr"
"tailscale.com/envknob" "tailscale.com/envknob"
"tailscale.com/metrics" "tailscale.com/metrics"
@ -87,6 +88,30 @@ func AllowDebugAccess(r *http.Request) bool {
return false return false
} }
// AcceptsEncoding reports whether r accepts the named encoding
// ("gzip", "br", etc).
func AcceptsEncoding(r *http.Request, enc string) bool {
h := r.Header.Get("Accept-Encoding")
if h == "" {
return false
}
if !strings.Contains(h, enc) && !mem.ContainsFold(mem.S(h), mem.S(enc)) {
return false
}
remain := h
for len(remain) > 0 {
var part string
part, remain, _ = strings.Cut(remain, ",")
part = strings.TrimSpace(part)
part, _, _ = strings.Cut(part, ";")
if part == enc {
return true
}
}
return false
}
// Protected wraps a provided debug handler, h, returning a Handler // Protected wraps a provided debug handler, h, returning a Handler
// that enforces AllowDebugAccess and returns forbidden replies for // that enforces AllowDebugAccess and returns forbidden replies for
// unauthorized requests. // unauthorized requests.

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@ -552,3 +552,31 @@ func (promWriter) WritePrometheus(w io.Writer, prefix string) {
func (promWriter) String() string { func (promWriter) String() string {
return "" return ""
} }
func TestAcceptsEncoding(t *testing.T) {
tests := []struct {
in, enc string
want bool
}{
{"", "gzip", false},
{"gzip", "gzip", true},
{"foo,gzip", "gzip", true},
{"foo, gzip", "gzip", true},
{"foo, gzip ", "gzip", true},
{"gzip, foo ", "gzip", true},
{"gzip, foo ", "br", false},
{"gzip, foo ", "fo", false},
{"gzip;q=1.2, foo ", "gzip", true},
{" gzip;q=1.2, foo ", "gzip", true},
}
for i, tt := range tests {
h := make(http.Header)
if tt.in != "" {
h.Set("Accept-Encoding", tt.in)
}
got := AcceptsEncoding(&http.Request{Header: h}, tt.enc)
if got != tt.want {
t.Errorf("%d. got %v; want %v", i, got, tt.want)
}
}
}