// Copyright 2013 The Prometheus Authors // 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 web import ( "context" "encoding/json" "fmt" "io" "io/ioutil" stdlog "log" "math" "net" "net/http" "net/http/pprof" "net/url" "os" "path" "path/filepath" "regexp" "runtime" "sort" "strings" "sync" "sync/atomic" template_text "text/template" "time" "github.com/go-kit/kit/log" "github.com/go-kit/kit/log/level" conntrack "github.com/mwitkow/go-conntrack" "github.com/opentracing-contrib/go-stdlib/nethttp" opentracing "github.com/opentracing/opentracing-go" "github.com/pkg/errors" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/client_golang/prometheus/promhttp" io_prometheus_client "github.com/prometheus/client_model/go" "github.com/prometheus/common/model" "github.com/prometheus/common/route" "github.com/prometheus/common/server" "github.com/prometheus/tsdb" "github.com/soheilhy/cmux" "golang.org/x/net/netutil" "google.golang.org/grpc" "github.com/prometheus/prometheus/config" "github.com/prometheus/prometheus/notifier" "github.com/prometheus/prometheus/promql" "github.com/prometheus/prometheus/rules" "github.com/prometheus/prometheus/scrape" "github.com/prometheus/prometheus/storage" prometheus_tsdb "github.com/prometheus/prometheus/storage/tsdb" "github.com/prometheus/prometheus/template" "github.com/prometheus/prometheus/util/httputil" api_v1 "github.com/prometheus/prometheus/web/api/v1" api_v2 "github.com/prometheus/prometheus/web/api/v2" "github.com/prometheus/prometheus/web/ui" ) var localhostRepresentations = []string{"127.0.0.1", "localhost"} // withStackTrace logs the stack trace in case the request panics. The function // will re-raise the error which will then be handled by the net/http package. // It is needed because the go-kit log package doesn't manage properly the // panics from net/http (see https://github.com/go-kit/kit/issues/233). func withStackTracer(h http.Handler, l log.Logger) http.Handler { return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { defer func() { if err := recover(); err != nil { const size = 64 << 10 buf := make([]byte, size) buf = buf[:runtime.Stack(buf, false)] level.Error(l).Log("msg", "panic while serving request", "client", r.RemoteAddr, "url", r.URL, "err", err, "stack", buf) panic(err) } }() h.ServeHTTP(w, r) }) } var ( requestDuration = prometheus.NewHistogramVec( prometheus.HistogramOpts{ Name: "prometheus_http_request_duration_seconds", Help: "Histogram of latencies for HTTP requests.", Buckets: []float64{.1, .2, .4, 1, 3, 8, 20, 60, 120}, }, []string{"handler"}, ) responseSize = prometheus.NewHistogramVec( prometheus.HistogramOpts{ Name: "prometheus_http_response_size_bytes", Help: "Histogram of response size for HTTP requests.", Buckets: prometheus.ExponentialBuckets(100, 10, 8), }, []string{"handler"}, ) ) func init() { prometheus.MustRegister(requestDuration, responseSize) } // Handler serves various HTTP endpoints of the Prometheus server type Handler struct { logger log.Logger scrapeManager *scrape.Manager ruleManager *rules.Manager queryEngine *promql.Engine context context.Context tsdb func() *tsdb.DB storage storage.Storage notifier *notifier.Manager apiV1 *api_v1.API router *route.Router quitCh chan struct{} reloadCh chan chan error options *Options config *config.Config versionInfo *PrometheusVersion birth time.Time cwd string flagsMap map[string]string mtx sync.RWMutex now func() model.Time ready uint32 // ready is uint32 rather than boolean to be able to use atomic functions. } // ApplyConfig updates the config field of the Handler struct func (h *Handler) ApplyConfig(conf *config.Config) error { h.mtx.Lock() defer h.mtx.Unlock() h.config = conf return nil } // PrometheusVersion contains build information about Prometheus. type PrometheusVersion struct { Version string `json:"version"` Revision string `json:"revision"` Branch string `json:"branch"` BuildUser string `json:"buildUser"` BuildDate string `json:"buildDate"` GoVersion string `json:"goVersion"` } // Options for the web Handler. type Options struct { Context context.Context TSDB func() *tsdb.DB TSDBCfg prometheus_tsdb.Options Storage storage.Storage QueryEngine *promql.Engine ScrapeManager *scrape.Manager RuleManager *rules.Manager Notifier *notifier.Manager Version *PrometheusVersion Flags map[string]string ListenAddress string CORSOrigin *regexp.Regexp ReadTimeout time.Duration MaxConnections int ExternalURL *url.URL RoutePrefix string UseLocalAssets bool UserAssetsPath string ConsoleTemplatesPath string ConsoleLibrariesPath string EnableLifecycle bool EnableAdminAPI bool PageTitle string RemoteReadSampleLimit int RemoteReadConcurrencyLimit int } func instrumentHandlerWithPrefix(prefix string) func(handlerName string, handler http.HandlerFunc) http.HandlerFunc { return func(handlerName string, handler http.HandlerFunc) http.HandlerFunc { return instrumentHandler(prefix+handlerName, handler) } } func instrumentHandler(handlerName string, handler http.HandlerFunc) http.HandlerFunc { return promhttp.InstrumentHandlerDuration( requestDuration.MustCurryWith(prometheus.Labels{"handler": handlerName}), promhttp.InstrumentHandlerResponseSize( responseSize.MustCurryWith(prometheus.Labels{"handler": handlerName}), handler, ), ) } // New initializes a new web Handler. func New(logger log.Logger, o *Options) *Handler { router := route.New().WithInstrumentation(instrumentHandler) cwd, err := os.Getwd() if err != nil { cwd = "" } if logger == nil { logger = log.NewNopLogger() } h := &Handler{ logger: logger, router: router, quitCh: make(chan struct{}), reloadCh: make(chan chan error), options: o, versionInfo: o.Version, birth: time.Now(), cwd: cwd, flagsMap: o.Flags, context: o.Context, scrapeManager: o.ScrapeManager, ruleManager: o.RuleManager, queryEngine: o.QueryEngine, tsdb: o.TSDB, storage: o.Storage, notifier: o.Notifier, now: model.Now, ready: 0, } h.apiV1 = api_v1.NewAPI(h.queryEngine, h.storage, h.scrapeManager, h.notifier, func() config.Config { h.mtx.RLock() defer h.mtx.RUnlock() return *h.config }, o.Flags, h.testReady, func() api_v1.TSDBAdmin { return h.options.TSDB() }, h.options.EnableAdminAPI, logger, h.ruleManager, h.options.RemoteReadSampleLimit, h.options.RemoteReadConcurrencyLimit, h.options.CORSOrigin, ) if o.RoutePrefix != "/" { // If the prefix is missing for the root path, prepend it. router.Get("/", func(w http.ResponseWriter, r *http.Request) { http.Redirect(w, r, o.RoutePrefix, http.StatusFound) }) router = router.WithPrefix(o.RoutePrefix) } readyf := h.testReady router.Get("/", func(w http.ResponseWriter, r *http.Request) { http.Redirect(w, r, path.Join(o.ExternalURL.Path, "/graph"), http.StatusFound) }) router.Get("/alerts", readyf(h.alerts)) router.Get("/graph", readyf(h.graph)) router.Get("/status", readyf(h.status)) router.Get("/flags", readyf(h.flags)) router.Get("/config", readyf(h.serveConfig)) router.Get("/rules", readyf(h.rules)) router.Get("/targets", readyf(h.targets)) router.Get("/version", readyf(h.version)) router.Get("/service-discovery", readyf(h.serviceDiscovery)) router.Get("/metrics", promhttp.Handler().ServeHTTP) router.Get("/federate", readyf(httputil.CompressionHandler{ Handler: http.HandlerFunc(h.federation), }.ServeHTTP)) router.Get("/consoles/*filepath", readyf(h.consoles)) router.Get("/static/*filepath", func(w http.ResponseWriter, r *http.Request) { r.URL.Path = path.Join("/static", route.Param(r.Context(), "filepath")) fs := server.StaticFileServer(ui.Assets) fs.ServeHTTP(w, r) }) if o.UserAssetsPath != "" { router.Get("/user/*filepath", route.FileServe(o.UserAssetsPath)) } if o.EnableLifecycle { router.Post("/-/quit", h.quit) router.Put("/-/quit", h.quit) router.Post("/-/reload", h.reload) router.Put("/-/reload", h.reload) } else { router.Post("/-/quit", func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusForbidden) w.Write([]byte("Lifecycle APIs are not enabled")) }) router.Post("/-/reload", func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusForbidden) w.Write([]byte("Lifecycle APIs are not enabled")) }) } router.Get("/-/quit", func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusMethodNotAllowed) w.Write([]byte("Only POST or PUT requests allowed")) }) router.Get("/-/reload", func(w http.ResponseWriter, _ *http.Request) { w.WriteHeader(http.StatusMethodNotAllowed) w.Write([]byte("Only POST or PUT requests allowed")) }) router.Get("/debug/*subpath", serveDebug) router.Post("/debug/*subpath", serveDebug) router.Get("/-/healthy", func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) fmt.Fprintf(w, "Prometheus is Healthy.\n") }) router.Get("/-/ready", readyf(func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(http.StatusOK) fmt.Fprintf(w, "Prometheus is Ready.\n") })) return h } func serveDebug(w http.ResponseWriter, req *http.Request) { ctx := req.Context() subpath := route.Param(ctx, "subpath") if subpath == "/pprof" { http.Redirect(w, req, req.URL.Path+"/", http.StatusMovedPermanently) return } if !strings.HasPrefix(subpath, "/pprof/") { http.NotFound(w, req) return } subpath = strings.TrimPrefix(subpath, "/pprof/") switch subpath { case "cmdline": pprof.Cmdline(w, req) case "profile": pprof.Profile(w, req) case "symbol": pprof.Symbol(w, req) case "trace": pprof.Trace(w, req) default: req.URL.Path = "/debug/pprof/" + subpath pprof.Index(w, req) } } // Ready sets Handler to be ready. func (h *Handler) Ready() { atomic.StoreUint32(&h.ready, 1) } // Verifies whether the server is ready or not. func (h *Handler) isReady() bool { ready := atomic.LoadUint32(&h.ready) return ready > 0 } // Checks if server is ready, calls f if it is, returns 503 if it is not. func (h *Handler) testReady(f http.HandlerFunc) http.HandlerFunc { return func(w http.ResponseWriter, r *http.Request) { if h.isReady() { f(w, r) } else { w.WriteHeader(http.StatusServiceUnavailable) fmt.Fprintf(w, "Service Unavailable") } } } // Checks if server is ready, calls f if it is, returns 503 if it is not. func (h *Handler) testReadyHandler(f http.Handler) http.HandlerFunc { return h.testReady(f.ServeHTTP) } // Quit returns the receive-only quit channel. func (h *Handler) Quit() <-chan struct{} { return h.quitCh } // Reload returns the receive-only channel that signals configuration reload requests. func (h *Handler) Reload() <-chan chan error { return h.reloadCh } // Run serves the HTTP endpoints. func (h *Handler) Run(ctx context.Context) error { level.Info(h.logger).Log("msg", "Start listening for connections", "address", h.options.ListenAddress) listener, err := net.Listen("tcp", h.options.ListenAddress) if err != nil { return err } listener = netutil.LimitListener(listener, h.options.MaxConnections) // Monitor incoming connections with conntrack. listener = conntrack.NewListener(listener, conntrack.TrackWithName("http"), conntrack.TrackWithTracing()) var ( m = cmux.New(listener) // See https://github.com/grpc/grpc-go/issues/2636 for why we need to use MatchWithWriters(). grpcl = m.MatchWithWriters(cmux.HTTP2MatchHeaderFieldSendSettings("content-type", "application/grpc")) httpl = m.Match(cmux.HTTP1Fast()) grpcSrv = grpc.NewServer() ) av2 := api_v2.New( h.options.TSDB, h.options.EnableAdminAPI, ) av2.RegisterGRPC(grpcSrv) hh, err := av2.HTTPHandler(ctx, h.options.ListenAddress) if err != nil { return err } hhFunc := h.testReadyHandler(hh) operationName := nethttp.OperationNameFunc(func(r *http.Request) string { return fmt.Sprintf("%s %s", r.Method, r.URL.Path) }) mux := http.NewServeMux() mux.Handle("/", h.router) av1 := route.New().WithInstrumentation(instrumentHandlerWithPrefix("/api/v1")) h.apiV1.Register(av1) apiPath := "/api" if h.options.RoutePrefix != "/" { apiPath = h.options.RoutePrefix + apiPath level.Info(h.logger).Log("msg", "router prefix", "prefix", h.options.RoutePrefix) } mux.Handle(apiPath+"/v1/", http.StripPrefix(apiPath+"/v1", av1)) mux.Handle(apiPath+"/", http.StripPrefix(apiPath, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) { httputil.SetCORS(w, h.options.CORSOrigin, r) hhFunc(w, r) }), )) errlog := stdlog.New(log.NewStdlibAdapter(level.Error(h.logger)), "", 0) httpSrv := &http.Server{ Handler: withStackTracer(nethttp.Middleware(opentracing.GlobalTracer(), mux, operationName), h.logger), ErrorLog: errlog, ReadTimeout: h.options.ReadTimeout, } errCh := make(chan error) go func() { errCh <- httpSrv.Serve(httpl) }() go func() { errCh <- grpcSrv.Serve(grpcl) }() go func() { errCh <- m.Serve() }() select { case e := <-errCh: return e case <-ctx.Done(): httpSrv.Shutdown(ctx) grpcSrv.GracefulStop() return nil } } func (h *Handler) alerts(w http.ResponseWriter, r *http.Request) { var groups []*rules.Group for _, group := range h.ruleManager.RuleGroups() { if group.HasAlertingRules() { groups = append(groups, group) } } alertStatus := AlertStatus{ Groups: groups, AlertStateToRowClass: map[rules.AlertState]string{ rules.StateInactive: "success", rules.StatePending: "warning", rules.StateFiring: "danger", }, } h.executeTemplate(w, "alerts.html", alertStatus) } func (h *Handler) consoles(w http.ResponseWriter, r *http.Request) { ctx := r.Context() name := route.Param(ctx, "filepath") file, err := http.Dir(h.options.ConsoleTemplatesPath).Open(name) if err != nil { http.Error(w, err.Error(), http.StatusNotFound) return } defer file.Close() text, err := ioutil.ReadAll(file) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } // Provide URL parameters as a map for easy use. Advanced users may have need for // parameters beyond the first, so provide RawParams. rawParams, err := url.ParseQuery(r.URL.RawQuery) if err != nil { http.Error(w, err.Error(), http.StatusBadRequest) return } params := map[string]string{} for k, v := range rawParams { params[k] = v[0] } externalLabels := map[string]string{} h.mtx.RLock() els := h.config.GlobalConfig.ExternalLabels h.mtx.RUnlock() for _, el := range els { externalLabels[el.Name] = el.Value } // Inject some convenience variables that are easier to remember for users // who are not used to Go's templating system. defs := []string{ "{{$rawParams := .RawParams }}", "{{$params := .Params}}", "{{$path := .Path}}", "{{$externalLabels := .ExternalLabels}}", } data := struct { RawParams url.Values Params map[string]string Path string ExternalLabels map[string]string }{ RawParams: rawParams, Params: params, Path: strings.TrimLeft(name, "/"), ExternalLabels: externalLabels, } tmpl := template.NewTemplateExpander( h.context, strings.Join(append(defs, string(text)), ""), "__console_"+name, data, h.now(), template.QueryFunc(rules.EngineQueryFunc(h.queryEngine, h.storage)), h.options.ExternalURL, ) filenames, err := filepath.Glob(h.options.ConsoleLibrariesPath + "/*.lib") if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } result, err := tmpl.ExpandHTML(filenames) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } io.WriteString(w, result) } func (h *Handler) graph(w http.ResponseWriter, r *http.Request) { h.executeTemplate(w, "graph.html", nil) } func (h *Handler) status(w http.ResponseWriter, r *http.Request) { status := struct { Birth time.Time CWD string Version *PrometheusVersion Alertmanagers []*url.URL GoroutineCount int GOMAXPROCS int GOGC string GODEBUG string CorruptionCount int64 ChunkCount int64 TimeSeriesCount int64 LastConfigTime time.Time ReloadConfigSuccess bool StorageRetention string }{ Birth: h.birth, CWD: h.cwd, Version: h.versionInfo, Alertmanagers: h.notifier.Alertmanagers(), GoroutineCount: runtime.NumGoroutine(), GOMAXPROCS: runtime.GOMAXPROCS(0), GOGC: os.Getenv("GOGC"), GODEBUG: os.Getenv("GODEBUG"), } if h.options.TSDBCfg.RetentionDuration != 0 { status.StorageRetention = h.options.TSDBCfg.RetentionDuration.String() } if h.options.TSDBCfg.MaxBytes != 0 { if status.StorageRetention != "" { status.StorageRetention = status.StorageRetention + " or " } status.StorageRetention = status.StorageRetention + h.options.TSDBCfg.MaxBytes.String() } metrics, err := prometheus.DefaultGatherer.Gather() if err != nil { http.Error(w, fmt.Sprintf("error gathering runtime status: %s", err), http.StatusInternalServerError) return } for _, mF := range metrics { switch *mF.Name { case "prometheus_tsdb_head_chunks": status.ChunkCount = int64(toFloat64(mF)) case "prometheus_tsdb_head_series": status.TimeSeriesCount = int64(toFloat64(mF)) case "prometheus_tsdb_wal_corruptions_total": status.CorruptionCount = int64(toFloat64(mF)) case "prometheus_config_last_reload_successful": status.ReloadConfigSuccess = toFloat64(mF) != 0 case "prometheus_config_last_reload_success_timestamp_seconds": status.LastConfigTime = time.Unix(int64(toFloat64(mF)), 0) } } h.executeTemplate(w, "status.html", status) } func toFloat64(f *io_prometheus_client.MetricFamily) float64 { m := *f.Metric[0] if m.Gauge != nil { return m.Gauge.GetValue() } if m.Counter != nil { return m.Counter.GetValue() } if m.Untyped != nil { return m.Untyped.GetValue() } return math.NaN() } func (h *Handler) flags(w http.ResponseWriter, r *http.Request) { h.executeTemplate(w, "flags.html", h.flagsMap) } func (h *Handler) serveConfig(w http.ResponseWriter, r *http.Request) { h.mtx.RLock() defer h.mtx.RUnlock() h.executeTemplate(w, "config.html", h.config.String()) } func (h *Handler) rules(w http.ResponseWriter, r *http.Request) { h.executeTemplate(w, "rules.html", h.ruleManager) } func (h *Handler) serviceDiscovery(w http.ResponseWriter, r *http.Request) { var index []string targets := h.scrapeManager.TargetsAll() for job := range targets { index = append(index, job) } sort.Strings(index) scrapeConfigData := struct { Index []string Targets map[string][]*scrape.Target Active []int Dropped []int Total []int }{ Index: index, Targets: make(map[string][]*scrape.Target), Active: make([]int, len(index)), Dropped: make([]int, len(index)), Total: make([]int, len(index)), } for i, job := range scrapeConfigData.Index { scrapeConfigData.Targets[job] = make([]*scrape.Target, 0, len(targets[job])) scrapeConfigData.Total[i] = len(targets[job]) for _, target := range targets[job] { // Do not display more than 100 dropped targets per job to avoid // returning too much data to the clients. if target.Labels().Len() == 0 { scrapeConfigData.Dropped[i]++ if scrapeConfigData.Dropped[i] > 100 { continue } } else { scrapeConfigData.Active[i]++ } scrapeConfigData.Targets[job] = append(scrapeConfigData.Targets[job], target) } } h.executeTemplate(w, "service-discovery.html", scrapeConfigData) } func (h *Handler) targets(w http.ResponseWriter, r *http.Request) { tps := h.scrapeManager.TargetsActive() for _, targets := range tps { sort.Slice(targets, func(i, j int) bool { iJobLabel := targets[i].Labels().Get(model.JobLabel) jJobLabel := targets[j].Labels().Get(model.JobLabel) if iJobLabel == jJobLabel { return targets[i].Labels().Get(model.InstanceLabel) < targets[j].Labels().Get(model.InstanceLabel) } return iJobLabel < jJobLabel }) } h.executeTemplate(w, "targets.html", struct { TargetPools map[string][]*scrape.Target }{ TargetPools: tps, }) } func (h *Handler) version(w http.ResponseWriter, r *http.Request) { dec := json.NewEncoder(w) if err := dec.Encode(h.versionInfo); err != nil { http.Error(w, fmt.Sprintf("error encoding JSON: %s", err), http.StatusInternalServerError) } } func (h *Handler) quit(w http.ResponseWriter, r *http.Request) { fmt.Fprintf(w, "Requesting termination... Goodbye!") close(h.quitCh) } func (h *Handler) reload(w http.ResponseWriter, r *http.Request) { rc := make(chan error) h.reloadCh <- rc if err := <-rc; err != nil { http.Error(w, fmt.Sprintf("failed to reload config: %s", err), http.StatusInternalServerError) } } func (h *Handler) consolesPath() string { if _, err := os.Stat(h.options.ConsoleTemplatesPath + "/index.html"); !os.IsNotExist(err) { return h.options.ExternalURL.Path + "/consoles/index.html" } if h.options.UserAssetsPath != "" { if _, err := os.Stat(h.options.UserAssetsPath + "/index.html"); !os.IsNotExist(err) { return h.options.ExternalURL.Path + "/user/index.html" } } return "" } func tmplFuncs(consolesPath string, opts *Options) template_text.FuncMap { return template_text.FuncMap{ "since": func(t time.Time) time.Duration { return time.Since(t) / time.Millisecond * time.Millisecond }, "consolesPath": func() string { return consolesPath }, "pathPrefix": func() string { return opts.ExternalURL.Path }, "pageTitle": func() string { return opts.PageTitle }, "buildVersion": func() string { return opts.Version.Revision }, "globalURL": func(u *url.URL) *url.URL { host, port, err := net.SplitHostPort(u.Host) if err != nil { return u } for _, lhr := range localhostRepresentations { if host == lhr { _, ownPort, err := net.SplitHostPort(opts.ListenAddress) if err != nil { return u } if port == ownPort { // Only in the case where the target is on localhost and its port is // the same as the one we're listening on, we know for sure that // we're monitoring our own process and that we need to change the // scheme, hostname, and port to the externally reachable ones as // well. We shouldn't need to touch the path at all, since if a // path prefix is defined, the path under which we scrape ourselves // should already contain the prefix. u.Scheme = opts.ExternalURL.Scheme u.Host = opts.ExternalURL.Host } else { // Otherwise, we only know that localhost is not reachable // externally, so we replace only the hostname by the one in the // external URL. It could be the wrong hostname for the service on // this port, but it's still the best possible guess. host, _, err := net.SplitHostPort(opts.ExternalURL.Host) if err != nil { return u } u.Host = host + ":" + port } break } } return u }, "numHealthy": func(pool []*scrape.Target) int { alive := len(pool) for _, p := range pool { if p.Health() != scrape.HealthGood { alive-- } } return alive }, "targetHealthToClass": func(th scrape.TargetHealth) string { switch th { case scrape.HealthUnknown: return "warning" case scrape.HealthGood: return "success" default: return "danger" } }, "ruleHealthToClass": func(rh rules.RuleHealth) string { switch rh { case rules.HealthUnknown: return "warning" case rules.HealthGood: return "success" default: return "danger" } }, "alertStateToClass": func(as rules.AlertState) string { switch as { case rules.StateInactive: return "success" case rules.StatePending: return "warning" case rules.StateFiring: return "danger" default: panic("unknown alert state") } }, } } func (h *Handler) getTemplate(name string) (string, error) { var tmpl string appendf := func(name string) error { f, err := ui.Assets.Open(path.Join("/templates", name)) if err != nil { return err } defer f.Close() b, err := ioutil.ReadAll(f) if err != nil { return err } tmpl += string(b) return nil } err := appendf("_base.html") if err != nil { return "", errors.Wrap(err, "error reading base template") } err = appendf(name) if err != nil { return "", errors.Wrapf(err, "error reading page template %s", name) } return tmpl, nil } func (h *Handler) executeTemplate(w http.ResponseWriter, name string, data interface{}) { text, err := h.getTemplate(name) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) } tmpl := template.NewTemplateExpander( h.context, text, name, data, h.now(), template.QueryFunc(rules.EngineQueryFunc(h.queryEngine, h.storage)), h.options.ExternalURL, ) tmpl.Funcs(tmplFuncs(h.consolesPath(), h.options)) result, err := tmpl.ExpandHTML(nil) if err != nil { http.Error(w, err.Error(), http.StatusInternalServerError) return } io.WriteString(w, result) } // AlertStatus bundles alerting rules and the mapping of alert states to row classes. type AlertStatus struct { Groups []*rules.Group AlertStateToRowClass map[rules.AlertState]string }