package agent import ( "encoding/json" "fmt" "io" "net" "net/http" "net/http/pprof" "net/url" "os" "regexp" "strconv" "strings" "time" "github.com/NYTimes/gziphandler" metrics "github.com/armon/go-metrics" "github.com/hashicorp/consul/acl" "github.com/hashicorp/consul/agent/cache" "github.com/hashicorp/consul/agent/structs" cleanhttp "github.com/hashicorp/go-cleanhttp" "github.com/mitchellh/mapstructure" "github.com/pkg/errors" ) // MethodNotAllowedError should be returned by a handler when the HTTP method is not allowed. type MethodNotAllowedError struct { Method string Allow []string } func (e MethodNotAllowedError) Error() string { return fmt.Sprintf("method %s not allowed", e.Method) } // BadRequestError should be returned by a handler when parameters or the payload are not valid type BadRequestError struct { Reason string } func (e BadRequestError) Error() string { return fmt.Sprintf("Bad request: %s", e.Reason) } // CodeWithPayloadError allow returning non HTTP 200 // Error codes while not returning PlainText payload type CodeWithPayloadError struct { Reason string StatusCode int ContentType string } func (e CodeWithPayloadError) Error() string { return e.Reason } type ForbiddenError struct { } func (e ForbiddenError) Error() string { return "Access is restricted" } // HTTPServer provides an HTTP api for an agent. type HTTPServer struct { *http.Server ln net.Listener agent *Agent blacklist *Blacklist // proto is filled by the agent to "http" or "https". proto string } type redirectFS struct { fs http.FileSystem } func (fs *redirectFS) Open(name string) (http.File, error) { file, err := fs.fs.Open(name) if err != nil { file, err = fs.fs.Open("/index.html") } return file, err } // endpoint is a Consul-specific HTTP handler that takes the usual arguments in // but returns a response object and error, both of which are handled in a // common manner by Consul's HTTP server. type endpoint func(resp http.ResponseWriter, req *http.Request) (interface{}, error) // unboundEndpoint is an endpoint method on a server. type unboundEndpoint func(s *HTTPServer, resp http.ResponseWriter, req *http.Request) (interface{}, error) // endpoints is a map from URL pattern to unbound endpoint. var endpoints map[string]unboundEndpoint // allowedMethods is a map from endpoint prefix to supported HTTP methods. // An empty slice means an endpoint handles OPTIONS requests and MethodNotFound errors itself. var allowedMethods map[string][]string // registerEndpoint registers a new endpoint, which should be done at package // init() time. func registerEndpoint(pattern string, methods []string, fn unboundEndpoint) { if endpoints == nil { endpoints = make(map[string]unboundEndpoint) } if endpoints[pattern] != nil || allowedMethods[pattern] != nil { panic(fmt.Errorf("Pattern %q is already registered", pattern)) } endpoints[pattern] = fn allowedMethods[pattern] = methods } // wrappedMux hangs on to the underlying mux for unit tests. type wrappedMux struct { mux *http.ServeMux handler http.Handler } // ServeHTTP implements the http.Handler interface. func (w *wrappedMux) ServeHTTP(resp http.ResponseWriter, req *http.Request) { w.handler.ServeHTTP(resp, req) } // handler is used to attach our handlers to the mux func (s *HTTPServer) handler(enableDebug bool) http.Handler { mux := http.NewServeMux() // handleFuncMetrics takes the given pattern and handler and wraps to produce // metrics based on the pattern and request. handleFuncMetrics := func(pattern string, handler http.HandlerFunc) { // Get the parts of the pattern. We omit any initial empty for the // leading slash, and put an underscore as a "thing" placeholder if we // see a trailing slash, which means the part after is parsed. This lets // us distinguish from things like /v1/query and /v1/query/. var parts []string for i, part := range strings.Split(pattern, "/") { if part == "" { if i == 0 { continue } part = "_" } parts = append(parts, part) } // Register the wrapper, which will close over the expensive-to-compute // parts from above. // TODO (kyhavlov): Convert this to utilize metric labels in a major release wrapper := func(resp http.ResponseWriter, req *http.Request) { start := time.Now() handler(resp, req) key := append([]string{"http", req.Method}, parts...) metrics.MeasureSince(key, start) } gzipWrapper, _ := gziphandler.GzipHandlerWithOpts(gziphandler.MinSize(0)) gzipHandler := gzipWrapper(http.HandlerFunc(wrapper)) mux.Handle(pattern, gzipHandler) } // handlePProf takes the given pattern and pprof handler // and wraps it to add authorization and metrics handlePProf := func(pattern string, handler http.HandlerFunc) { wrapper := func(resp http.ResponseWriter, req *http.Request) { var token string s.parseToken(req, &token) rule, err := s.agent.resolveToken(token) if err != nil { resp.WriteHeader(http.StatusForbidden) return } // If enableDebug is not set, and ACLs are disabled, write // an unauthorized response if !enableDebug { if s.checkACLDisabled(resp, req) { return } } // If the token provided does not have the necessary permissions, // write a forbidden response if rule != nil && !rule.OperatorRead() { resp.WriteHeader(http.StatusForbidden) return } // Call the pprof handler handler(resp, req) } handleFuncMetrics(pattern, http.HandlerFunc(wrapper)) } mux.HandleFunc("/", s.Index) for pattern, fn := range endpoints { thisFn := fn methods, _ := allowedMethods[pattern] bound := func(resp http.ResponseWriter, req *http.Request) (interface{}, error) { return thisFn(s, resp, req) } handleFuncMetrics(pattern, s.wrap(bound, methods)) } // Register wrapped pprof handlers handlePProf("/debug/pprof/", pprof.Index) handlePProf("/debug/pprof/cmdline", pprof.Cmdline) handlePProf("/debug/pprof/profile", pprof.Profile) handlePProf("/debug/pprof/symbol", pprof.Symbol) handlePProf("/debug/pprof/trace", pprof.Trace) if s.IsUIEnabled() { legacy_ui, err := strconv.ParseBool(os.Getenv("CONSUL_UI_LEGACY")) if err != nil { legacy_ui = false } var uifs http.FileSystem // Use the custom UI dir if provided. if s.agent.config.UIDir != "" { uifs = http.Dir(s.agent.config.UIDir) } else { fs := assetFS() if legacy_ui { fs.Prefix += "/v1/" } else { fs.Prefix += "/v2/" } uifs = fs } if !legacy_ui { uifs = &redirectFS{fs: uifs} } mux.Handle("/robots.txt", http.FileServer(uifs)) mux.Handle("/ui/", http.StripPrefix("/ui/", http.FileServer(uifs))) } // Wrap the whole mux with a handler that bans URLs with non-printable // characters, unless disabled explicitly to deal with old keys that fail this // check. h := cleanhttp.PrintablePathCheckHandler(mux, nil) if s.agent.config.DisableHTTPUnprintableCharFilter { h = mux } return &wrappedMux{ mux: mux, handler: h, } } // nodeName returns the node name of the agent func (s *HTTPServer) nodeName() string { return s.agent.config.NodeName } // aclEndpointRE is used to find old ACL endpoints that take tokens in the URL // so that we can redact them. The ACL endpoints that take the token in the URL // are all of the form /v1/acl//, and can optionally include query // parameters which are indicated by a question mark. We capture the part before // the token, the token, and any query parameters after, and then reassemble as // $1$3 (the token in $2 isn't used), which will give: // // /v1/acl/clone/foo -> /v1/acl/clone/ // /v1/acl/clone/foo?token=bar -> /v1/acl/clone/?token= // // The query parameter in the example above is obfuscated like any other, after // this regular expression is applied, so the regular expression substitution // results in: // // /v1/acl/clone/foo?token=bar -> /v1/acl/clone/?token=bar // ^---- $1 ----^^- $2 -^^-- $3 --^ // // And then the loop that looks for parameters called "token" does the last // step to get to the final redacted form. var ( aclEndpointRE = regexp.MustCompile("^(/v1/acl/(create|update|destroy|info|clone|list)/)([^?]+)([?]?.*)$") ) // wrap is used to wrap functions to make them more convenient func (s *HTTPServer) wrap(handler endpoint, methods []string) http.HandlerFunc { return func(resp http.ResponseWriter, req *http.Request) { setHeaders(resp, s.agent.config.HTTPResponseHeaders) setTranslateAddr(resp, s.agent.config.TranslateWANAddrs) // Obfuscate any tokens from appearing in the logs formVals, err := url.ParseQuery(req.URL.RawQuery) if err != nil { s.agent.logger.Printf("[ERR] http: Failed to decode query: %s from=%s", err, req.RemoteAddr) resp.WriteHeader(http.StatusInternalServerError) return } logURL := req.URL.String() if tokens, ok := formVals["token"]; ok { for _, token := range tokens { if token == "" { logURL += "" continue } logURL = strings.Replace(logURL, token, "", -1) } } logURL = aclEndpointRE.ReplaceAllString(logURL, "$1$4") if s.blacklist.Block(req.URL.Path) { errMsg := "Endpoint is blocked by agent configuration" s.agent.logger.Printf("[ERR] http: Request %s %v, error: %v from=%s", req.Method, logURL, err, req.RemoteAddr) resp.WriteHeader(http.StatusForbidden) fmt.Fprint(resp, errMsg) return } isForbidden := func(err error) bool { if acl.IsErrPermissionDenied(err) || acl.IsErrNotFound(err) { return true } _, ok := err.(ForbiddenError) return ok } isMethodNotAllowed := func(err error) bool { _, ok := err.(MethodNotAllowedError) return ok } isBadRequest := func(err error) bool { _, ok := err.(BadRequestError) return ok } addAllowHeader := func(methods []string) { resp.Header().Add("Allow", strings.Join(methods, ",")) } handleErr := func(err error) { s.agent.logger.Printf("[ERR] http: Request %s %v, error: %v from=%s", req.Method, logURL, err, req.RemoteAddr) switch { case isForbidden(err): resp.WriteHeader(http.StatusForbidden) fmt.Fprint(resp, err.Error()) case structs.IsErrRPCRateExceeded(err): resp.WriteHeader(http.StatusTooManyRequests) case isMethodNotAllowed(err): // RFC2616 states that for 405 Method Not Allowed the response // MUST include an Allow header containing the list of valid // methods for the requested resource. // https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html addAllowHeader(err.(MethodNotAllowedError).Allow) resp.WriteHeader(http.StatusMethodNotAllowed) // 405 fmt.Fprint(resp, err.Error()) case isBadRequest(err): resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, err.Error()) default: resp.WriteHeader(http.StatusInternalServerError) fmt.Fprint(resp, err.Error()) } } start := time.Now() defer func() { s.agent.logger.Printf("[DEBUG] http: Request %s %v (%v) from=%s", req.Method, logURL, time.Since(start), req.RemoteAddr) }() var obj interface{} // if this endpoint has declared methods, respond appropriately to OPTIONS requests. Otherwise let the endpoint handle that. if req.Method == "OPTIONS" && len(methods) > 0 { addAllowHeader(append([]string{"OPTIONS"}, methods...)) return } // if this endpoint has declared methods, check the request method. Otherwise let the endpoint handle that. methodFound := len(methods) == 0 for _, method := range methods { if method == req.Method { methodFound = true break } } if !methodFound { err = MethodNotAllowedError{req.Method, append([]string{"OPTIONS"}, methods...)} } else { err = s.checkWriteAccess(req) if err == nil { // Invoke the handler obj, err = handler(resp, req) } } contentType := "application/json" httpCode := http.StatusOK if err != nil { if errPayload, ok := err.(CodeWithPayloadError); ok { httpCode = errPayload.StatusCode if errPayload.ContentType != "" { contentType = errPayload.ContentType } if errPayload.Reason != "" { resp.Header().Add("X-Consul-Reason", errPayload.Reason) } } else { handleErr(err) return } } if obj == nil { return } var buf []byte if contentType == "application/json" { buf, err = s.marshalJSON(req, obj) if err != nil { handleErr(err) return } } else { if strings.HasPrefix(contentType, "text/") { if val, ok := obj.(string); ok { buf = []byte(val) } } } resp.Header().Set("Content-Type", contentType) resp.WriteHeader(httpCode) resp.Write(buf) } } // marshalJSON marshals the object into JSON, respecting the user's pretty-ness // configuration. func (s *HTTPServer) marshalJSON(req *http.Request, obj interface{}) ([]byte, error) { if _, ok := req.URL.Query()["pretty"]; ok || s.agent.config.DevMode { buf, err := json.MarshalIndent(obj, "", " ") if err != nil { return nil, err } buf = append(buf, "\n"...) return buf, nil } buf, err := json.Marshal(obj) if err != nil { return nil, err } return buf, err } // Returns true if the UI is enabled. func (s *HTTPServer) IsUIEnabled() bool { return s.agent.config.UIDir != "" || s.agent.config.EnableUI } // Renders a simple index page func (s *HTTPServer) Index(resp http.ResponseWriter, req *http.Request) { // Check if this is a non-index path if req.URL.Path != "/" { resp.WriteHeader(http.StatusNotFound) return } // Give them something helpful if there's no UI so they at least know // what this server is. if !s.IsUIEnabled() { fmt.Fprint(resp, "Consul Agent") return } // Redirect to the UI endpoint http.Redirect(resp, req, "/ui/", http.StatusMovedPermanently) // 301 } // decodeBody is used to decode a JSON request body func decodeBody(req *http.Request, out interface{}, cb func(interface{}) error) error { // This generally only happens in tests since real HTTP requests set // a non-nil body with no content. We guard against it anyways to prevent // a panic. The EOF response is the same behavior as an empty reader. if req.Body == nil { return io.EOF } var raw interface{} dec := json.NewDecoder(req.Body) if err := dec.Decode(&raw); err != nil { return err } // Invoke the callback prior to decode if cb != nil { if err := cb(raw); err != nil { return err } } return mapstructure.Decode(raw, out) } // setTranslateAddr is used to set the address translation header. This is only // present if the feature is active. func setTranslateAddr(resp http.ResponseWriter, active bool) { if active { resp.Header().Set("X-Consul-Translate-Addresses", "true") } } // setIndex is used to set the index response header func setIndex(resp http.ResponseWriter, index uint64) { // If we ever return X-Consul-Index of 0 blocking clients will go into a busy // loop and hammer us since ?index=0 will never block. It's always safe to // return index=1 since the very first Raft write is always an internal one // writing the raft config for the cluster so no user-facing blocking query // will ever legitimately have an X-Consul-Index of 1. if index == 0 { index = 1 } resp.Header().Set("X-Consul-Index", strconv.FormatUint(index, 10)) } // setKnownLeader is used to set the known leader header func setKnownLeader(resp http.ResponseWriter, known bool) { s := "true" if !known { s = "false" } resp.Header().Set("X-Consul-KnownLeader", s) } func setConsistency(resp http.ResponseWriter, consistency string) { if consistency != "" { resp.Header().Set("X-Consul-Effective-Consistency", consistency) } } // setLastContact is used to set the last contact header func setLastContact(resp http.ResponseWriter, last time.Duration) { if last < 0 { last = 0 } lastMsec := uint64(last / time.Millisecond) resp.Header().Set("X-Consul-LastContact", strconv.FormatUint(lastMsec, 10)) } // setMeta is used to set the query response meta data func setMeta(resp http.ResponseWriter, m *structs.QueryMeta) { setIndex(resp, m.Index) setLastContact(resp, m.LastContact) setKnownLeader(resp, m.KnownLeader) setConsistency(resp, m.ConsistencyLevel) } // setCacheMeta sets http response headers to indicate cache status. func setCacheMeta(resp http.ResponseWriter, m *cache.ResultMeta) { if m == nil { return } str := "MISS" if m.Hit { str = "HIT" } resp.Header().Set("X-Cache", str) if m.Hit { resp.Header().Set("Age", fmt.Sprintf("%.0f", m.Age.Seconds())) } } // setHeaders is used to set canonical response header fields func setHeaders(resp http.ResponseWriter, headers map[string]string) { for field, value := range headers { resp.Header().Set(http.CanonicalHeaderKey(field), value) } } // parseWait is used to parse the ?wait and ?index query params // Returns true on error func parseWait(resp http.ResponseWriter, req *http.Request, b *structs.QueryOptions) bool { query := req.URL.Query() if wait := query.Get("wait"); wait != "" { dur, err := time.ParseDuration(wait) if err != nil { resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, "Invalid wait time") return true } b.MaxQueryTime = dur } if idx := query.Get("index"); idx != "" { index, err := strconv.ParseUint(idx, 10, 64) if err != nil { resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, "Invalid index") return true } b.MinQueryIndex = index } return false } // parseCacheControl parses the CacheControl HTTP header value. So far we only // support maxage directive. func parseCacheControl(resp http.ResponseWriter, req *http.Request, b *structs.QueryOptions) bool { raw := strings.ToLower(req.Header.Get("Cache-Control")) if raw == "" { return false } // Didn't want to import a full parser for this. While quoted strings are // allowed in some directives, max-age does not allow them per // https://tools.ietf.org/html/rfc7234#section-5.2.2.8 so we assume all // well-behaved clients use the exact token form of max-age= // where delta-seconds is a non-negative decimal integer. directives := strings.Split(raw, ",") parseDurationOrFail := func(raw string) (time.Duration, bool) { i, err := strconv.Atoi(raw) if err != nil { resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, "Invalid Cache-Control header.") return 0, true } return time.Duration(i) * time.Second, false } for _, d := range directives { d = strings.ToLower(strings.TrimSpace(d)) if d == "must-revalidate" { b.MustRevalidate = true } if strings.HasPrefix(d, "max-age=") { d, failed := parseDurationOrFail(d[8:]) if failed { return true } b.MaxAge = d if d == 0 { // max-age=0 specifically means that we need to consider the cache stale // immediately however MaxAge = 0 is indistinguishable from the default // where MaxAge is unset. b.MustRevalidate = true } } if strings.HasPrefix(d, "stale-if-error=") { d, failed := parseDurationOrFail(d[15:]) if failed { return true } b.StaleIfError = d } } return false } // parseConsistency is used to parse the ?stale and ?consistent query params. // Returns true on error func (s *HTTPServer) parseConsistency(resp http.ResponseWriter, req *http.Request, b *structs.QueryOptions) bool { query := req.URL.Query() defaults := true if _, ok := query["stale"]; ok { b.AllowStale = true defaults = false } if _, ok := query["consistent"]; ok { b.RequireConsistent = true defaults = false } if _, ok := query["leader"]; ok { defaults = false } if _, ok := query["cached"]; ok { b.UseCache = true defaults = false } if maxStale := query.Get("max_stale"); maxStale != "" { dur, err := time.ParseDuration(maxStale) if err != nil { resp.WriteHeader(http.StatusBadRequest) fmt.Fprintf(resp, "Invalid max_stale value %q", maxStale) return true } b.MaxStaleDuration = dur if dur.Nanoseconds() > 0 { b.AllowStale = true defaults = false } } // No specific Consistency has been specified by caller if defaults { path := req.URL.Path if strings.HasPrefix(path, "/v1/catalog") || strings.HasPrefix(path, "/v1/health") { if s.agent.config.DiscoveryMaxStale.Nanoseconds() > 0 { b.MaxStaleDuration = s.agent.config.DiscoveryMaxStale b.AllowStale = true } } } if b.AllowStale && b.RequireConsistent { resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, "Cannot specify ?stale with ?consistent, conflicting semantics.") return true } if b.UseCache && b.RequireConsistent { resp.WriteHeader(http.StatusBadRequest) fmt.Fprint(resp, "Cannot specify ?cached with ?consistent, conflicting semantics.") return true } return false } // parseDC is used to parse the ?dc query param func (s *HTTPServer) parseDC(req *http.Request, dc *string) { if other := req.URL.Query().Get("dc"); other != "" { *dc = other } else if *dc == "" { *dc = s.agent.config.Datacenter } } // parseTokenInternal is used to parse the ?token query param or the X-Consul-Token header or // Authorization Bearer token (RFC6750) and // optionally resolve proxy tokens to real ACL tokens. If the token is invalid or not specified it will populate // the token with the agents UserToken (acl_token in the consul configuration) // Parsing has the following priority: ?token, X-Consul-Token and last "Authorization: Bearer " func (s *HTTPServer) parseTokenInternal(req *http.Request, token *string, resolveProxyToken bool) { tok := "" if other := req.URL.Query().Get("token"); other != "" { tok = other } else if other := req.Header.Get("X-Consul-Token"); other != "" { tok = other } else if other := req.Header.Get("Authorization"); other != "" { // HTTP Authorization headers are in the format: [SPACE] // Ref. https://tools.ietf.org/html/rfc7236#section-3 parts := strings.Split(other, " ") // Authorization Header is invalid if containing 1 or 0 parts, e.g.: // "" || "" || "" || "" if len(parts) > 1 { scheme := parts[0] // Everything after "" is "", trimmed value := strings.TrimSpace(strings.Join(parts[1:], " ")) // must be "Bearer" if scheme == "Bearer" { // Since Bearer tokens shouldnt contain spaces (rfc6750#section-2.1) // "value" is tokenized, only the first item is used tok = strings.TrimSpace(strings.Split(value, " ")[0]) } } } if tok != "" { if resolveProxyToken { if p := s.agent.resolveProxyToken(tok); p != nil { *token = s.agent.State.ServiceToken(p.Proxy.TargetServiceID) return } } *token = tok return } *token = s.agent.tokens.UserToken() } // parseToken is used to parse the ?token query param or the X-Consul-Token header or // Authorization Bearer token header (RFC6750) and resolve proxy tokens to real ACL tokens func (s *HTTPServer) parseToken(req *http.Request, token *string) { s.parseTokenInternal(req, token, true) } // parseTokenWithoutResolvingProxyToken is used to parse the ?token query param or the X-Consul-Token header // or Authorization Bearer header token (RFC6750) and func (s *HTTPServer) parseTokenWithoutResolvingProxyToken(req *http.Request, token *string) { s.parseTokenInternal(req, token, false) } func sourceAddrFromRequest(req *http.Request) string { xff := req.Header.Get("X-Forwarded-For") forwardHosts := strings.Split(xff, ",") if len(forwardHosts) > 0 { forwardIp := net.ParseIP(strings.TrimSpace(forwardHosts[0])) if forwardIp != nil { return forwardIp.String() } } host, _, err := net.SplitHostPort(req.RemoteAddr) if err != nil { return "" } ip := net.ParseIP(host) if ip != nil { return ip.String() } else { return "" } } // parseSource is used to parse the ?near= query parameter, used for // sorting by RTT based on a source node. We set the source's DC to the target // DC in the request, if given, or else the agent's DC. func (s *HTTPServer) parseSource(req *http.Request, source *structs.QuerySource) { s.parseDC(req, &source.Datacenter) source.Ip = sourceAddrFromRequest(req) if node := req.URL.Query().Get("near"); node != "" { if node == "_agent" { source.Node = s.agent.config.NodeName } else { source.Node = node } } } // parseMetaFilter is used to parse the ?node-meta=key:value query parameter, used for // filtering results to nodes with the given metadata key/value func (s *HTTPServer) parseMetaFilter(req *http.Request) map[string]string { if filterList, ok := req.URL.Query()["node-meta"]; ok { filters := make(map[string]string) for _, filter := range filterList { key, value := ParseMetaPair(filter) filters[key] = value } return filters } return nil } // parseInternal is a convenience method for endpoints that need // to use both parseWait and parseDC. func (s *HTTPServer) parseInternal(resp http.ResponseWriter, req *http.Request, dc *string, b *structs.QueryOptions, resolveProxyToken bool) bool { s.parseDC(req, dc) s.parseTokenInternal(req, &b.Token, resolveProxyToken) if s.parseConsistency(resp, req, b) { return true } if parseCacheControl(resp, req, b) { return true } return parseWait(resp, req, b) } // parse is a convenience method for endpoints that need // to use both parseWait and parseDC. func (s *HTTPServer) parse(resp http.ResponseWriter, req *http.Request, dc *string, b *structs.QueryOptions) bool { return s.parseInternal(resp, req, dc, b, true) } // parseWithoutResolvingProxyToken is a convenience method similar to parse except that it disables resolving proxy tokens func (s *HTTPServer) parseWithoutResolvingProxyToken(resp http.ResponseWriter, req *http.Request, dc *string, b *structs.QueryOptions) bool { return s.parseInternal(resp, req, dc, b, false) } func (s *HTTPServer) checkWriteAccess(req *http.Request) error { if req.Method == http.MethodGet || req.Method == http.MethodHead || req.Method == http.MethodOptions { return nil } allowed := s.agent.config.AllowWriteHTTPFrom if len(allowed) == 0 { return nil } ipStr, _, err := net.SplitHostPort(req.RemoteAddr) if err != nil { return errors.Wrap(err, "unable to parse remote addr") } ip := net.ParseIP(ipStr) for _, n := range allowed { if n.Contains(ip) { return nil } } return ForbiddenError{} }