dendrite/internal/httputil/httpapi.go
2022-09-05 17:35:43 +01:00

286 lines
9.5 KiB
Go

// Copyright 2020 The Matrix.org Foundation C.I.C.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package httputil
import (
"fmt"
"io"
"net/http"
"net/http/httptest"
"net/http/httputil"
"os"
"strings"
"github.com/getsentry/sentry-go"
"github.com/matrix-org/dendrite/clientapi/auth"
"github.com/matrix-org/dendrite/clientapi/jsonerror"
userapi "github.com/matrix-org/dendrite/userapi/api"
"github.com/matrix-org/util"
opentracing "github.com/opentracing/opentracing-go"
"github.com/opentracing/opentracing-go/ext"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/sirupsen/logrus"
)
// BasicAuth is used for authorization on /metrics handlers
type BasicAuth struct {
Username string `yaml:"username"`
Password string `yaml:"password"`
}
// MakeAuthAPI turns a util.JSONRequestHandler function into an http.Handler which authenticates the request.
func MakeAuthAPI(
metricsName string, userAPI userapi.QueryAcccessTokenAPI,
f func(*http.Request, *userapi.Device) util.JSONResponse,
) http.Handler {
h := func(req *http.Request) util.JSONResponse {
logger := util.GetLogger(req.Context())
device, err := auth.VerifyUserFromRequest(req, userAPI)
if err != nil {
logger.Debugf("VerifyUserFromRequest %s -> HTTP %d", req.RemoteAddr, err.Code)
return *err
}
// add the user ID to the logger
logger = logger.WithField("user_id", device.UserID)
req = req.WithContext(util.ContextWithLogger(req.Context(), logger))
// add the user to Sentry, if enabled
hub := sentry.GetHubFromContext(req.Context())
if hub != nil {
hub.Scope().SetUser(sentry.User{
Username: device.UserID,
IPAddress: req.RemoteAddr,
})
hub.Scope().SetTag("user_id", device.UserID)
hub.Scope().SetTag("device_id", device.ID)
}
defer func() {
if r := recover(); r != nil {
if hub != nil {
hub.CaptureException(fmt.Errorf("%s panicked", req.URL.Path))
}
// re-panic to return the 500
panic(r)
}
}()
jsonRes := f(req, device)
// do not log 4xx as errors as they are client fails, not server fails
if hub != nil && jsonRes.Code >= 500 {
hub.Scope().SetExtra("response", jsonRes)
hub.CaptureException(fmt.Errorf("%s returned HTTP %d", req.URL.Path, jsonRes.Code))
}
return jsonRes
}
return MakeExternalAPI(metricsName, h)
}
// MakeAdminAPI is a wrapper around MakeAuthAPI which enforces that the request can only be
// completed by a user that is a server administrator.
func MakeAdminAPI(
metricsName string, userAPI userapi.QueryAcccessTokenAPI,
f func(*http.Request, *userapi.Device) util.JSONResponse,
) http.Handler {
return MakeAuthAPI(metricsName, userAPI, func(req *http.Request, device *userapi.Device) util.JSONResponse {
if device.AccountType != userapi.AccountTypeAdmin {
return util.JSONResponse{
Code: http.StatusForbidden,
JSON: jsonerror.Forbidden("This API can only be used by admin users."),
}
}
return f(req, device)
})
}
// MakeExternalAPI turns a util.JSONRequestHandler function into an http.Handler.
// This is used for APIs that are called from the internet.
func MakeExternalAPI(metricsName string, f func(*http.Request) util.JSONResponse) http.Handler {
// TODO: We shouldn't be directly reading env vars here, inject it in instead.
// Refactor this when we split out config structs.
verbose := false
if os.Getenv("DENDRITE_TRACE_HTTP") == "1" {
verbose = true
}
h := util.MakeJSONAPI(util.NewJSONRequestHandler(f))
withSpan := func(w http.ResponseWriter, req *http.Request) {
nextWriter := w
if verbose {
logger := logrus.NewEntry(logrus.StandardLogger())
// Log outgoing response
rec := httptest.NewRecorder()
nextWriter = rec
defer func() {
resp := rec.Result()
dump, err := httputil.DumpResponse(resp, true)
if err != nil {
logger.Debugf("Failed to dump outgoing response: %s", err)
} else {
strSlice := strings.Split(string(dump), "\n")
for _, s := range strSlice {
logger.Debug(s)
}
}
// copy the response to the client
for hdr, vals := range resp.Header {
for _, val := range vals {
w.Header().Add(hdr, val)
}
}
w.WriteHeader(resp.StatusCode)
// discard errors as this is for debugging
_, _ = io.Copy(w, resp.Body)
_ = resp.Body.Close()
}()
// Log incoming request
dump, err := httputil.DumpRequest(req, true)
if err != nil {
logger.Debugf("Failed to dump incoming request: %s", err)
} else {
strSlice := strings.Split(string(dump), "\n")
for _, s := range strSlice {
logger.Debug(s)
}
}
}
span := opentracing.StartSpan(metricsName)
defer span.Finish()
req = req.WithContext(opentracing.ContextWithSpan(req.Context(), span))
h.ServeHTTP(nextWriter, req)
}
return http.HandlerFunc(withSpan)
}
// MakeHTMLAPI adds Span metrics to the HTML Handler function
// This is used to serve HTML alongside JSON error messages
func MakeHTMLAPI(metricsName string, f func(http.ResponseWriter, *http.Request) *util.JSONResponse) http.Handler {
withSpan := func(w http.ResponseWriter, req *http.Request) {
span := opentracing.StartSpan(metricsName)
defer span.Finish()
req = req.WithContext(opentracing.ContextWithSpan(req.Context(), span))
if err := f(w, req); err != nil {
h := util.MakeJSONAPI(util.NewJSONRequestHandler(func(req *http.Request) util.JSONResponse {
return *err
}))
h.ServeHTTP(w, req)
}
}
return promhttp.InstrumentHandlerCounter(
promauto.NewCounterVec(
prometheus.CounterOpts{
Name: metricsName,
Help: "Total number of http requests for HTML resources",
Namespace: "dendrite",
},
[]string{"code"},
),
http.HandlerFunc(withSpan),
)
}
// MakeInternalAPI turns a util.JSONRequestHandler function into an http.Handler.
// This is used for APIs that are internal to dendrite.
// If we are passed a tracing context in the request headers then we use that
// as the parent of any tracing spans we create.
func MakeInternalAPI(metricsName string, f func(*http.Request) util.JSONResponse) http.Handler {
h := util.MakeJSONAPI(util.NewJSONRequestHandler(f))
withSpan := func(w http.ResponseWriter, req *http.Request) {
carrier := opentracing.HTTPHeadersCarrier(req.Header)
tracer := opentracing.GlobalTracer()
clientContext, err := tracer.Extract(opentracing.HTTPHeaders, carrier)
var span opentracing.Span
if err == nil {
// Default to a span without RPC context.
span = tracer.StartSpan(metricsName)
} else {
// Set the RPC context.
span = tracer.StartSpan(metricsName, ext.RPCServerOption(clientContext))
}
defer span.Finish()
req = req.WithContext(opentracing.ContextWithSpan(req.Context(), span))
h.ServeHTTP(w, req)
}
return promhttp.InstrumentHandlerCounter(
promauto.NewCounterVec(
prometheus.CounterOpts{
Name: metricsName + "_requests_total",
Help: "Total number of internal API calls",
Namespace: "dendrite",
},
[]string{"code"},
),
promhttp.InstrumentHandlerResponseSize(
promauto.NewHistogramVec(
prometheus.HistogramOpts{
Namespace: "dendrite",
Name: metricsName + "_response_size_bytes",
Help: "A histogram of response sizes for requests.",
Buckets: []float64{200, 500, 900, 1500, 5000, 15000, 50000, 100000},
},
[]string{},
),
http.HandlerFunc(withSpan),
),
)
}
// WrapHandlerInBasicAuth adds basic auth to a handler. Only used for /metrics
func WrapHandlerInBasicAuth(h http.Handler, b BasicAuth) http.HandlerFunc {
if b.Username == "" || b.Password == "" {
logrus.Warn("Metrics are exposed without protection. Make sure you set up protection at proxy level.")
}
return func(w http.ResponseWriter, r *http.Request) {
// Serve without authorization if either Username or Password is unset
if b.Username == "" || b.Password == "" {
h.ServeHTTP(w, r)
return
}
user, pass, ok := r.BasicAuth()
if !ok || user != b.Username || pass != b.Password {
http.Error(w, http.StatusText(http.StatusForbidden), http.StatusForbidden)
return
}
h.ServeHTTP(w, r)
}
}
// WrapHandlerInCORS adds CORS headers to all responses, including all error
// responses.
// Handles OPTIONS requests directly.
func WrapHandlerInCORS(h http.Handler) http.HandlerFunc {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Access-Control-Allow-Origin", "*")
w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS")
w.Header().Set("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization")
if r.Method == http.MethodOptions && r.Header.Get("Access-Control-Request-Method") != "" {
// Its easiest just to always return a 200 OK for everything. Whether
// this is technically correct or not is a question, but in the end this
// is what a lot of other people do (including synapse) and the clients
// are perfectly happy with it.
w.WriteHeader(http.StatusOK)
} else {
h.ServeHTTP(w, r)
}
})
}