// 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 ( "encoding/json" "fmt" "io" "io/ioutil" "net" "net/http" "net/url" "os" "path/filepath" "sort" "strings" "sync" "time" pprof_runtime "runtime/pprof" template_text "text/template" "github.com/prometheus/client_golang/prometheus" "github.com/prometheus/common/model" "github.com/prometheus/log" "github.com/prometheus/prometheus/config" "github.com/prometheus/prometheus/promql" "github.com/prometheus/prometheus/retrieval" "github.com/prometheus/prometheus/rules" "github.com/prometheus/prometheus/storage/local" "github.com/prometheus/prometheus/template" "github.com/prometheus/prometheus/util/route" "github.com/prometheus/prometheus/version" "github.com/prometheus/prometheus/web/api/legacy" "github.com/prometheus/prometheus/web/api/v1" "github.com/prometheus/prometheus/web/blob" ) var localhostRepresentations = []string{"127.0.0.1", "localhost"} // Handler serves various HTTP endpoints of the Prometheus server type Handler struct { ruleManager *rules.Manager queryEngine *promql.Engine storage local.Storage apiV1 *v1.API apiLegacy *legacy.API router *route.Router listenErrCh chan error quitCh chan struct{} reloadCh chan struct{} options *Options statusInfo *PrometheusStatus globalLabels model.LabelSet mtx sync.RWMutex } // ApplyConfig updates the status state as the new config requires. // Returns true on success. func (h *Handler) ApplyConfig(conf *config.Config) bool { h.mtx.Lock() defer h.mtx.Unlock() h.globalLabels = conf.GlobalConfig.Labels return true } // PrometheusStatus contains various information about the status // of the running Prometheus process. type PrometheusStatus struct { Birth time.Time Flags map[string]string Config string // A function that returns the current scrape targets pooled // by their job name. TargetPools func() map[string][]*retrieval.Target // A function that returns all loaded rules. Rules func() []rules.Rule mu sync.RWMutex } // ApplyConfig updates the status state as the new config requires. // Returns true on success. func (s *PrometheusStatus) ApplyConfig(conf *config.Config) bool { s.mu.Lock() defer s.mu.Unlock() s.Config = conf.String() return true } // Options for the web Handler. type Options struct { ListenAddress string ExternalURL *url.URL MetricsPath string UseLocalAssets bool UserAssetsPath string ConsoleTemplatesPath string ConsoleLibrariesPath string EnableQuit bool } // New initializes a new web Handler. func New(st local.Storage, qe *promql.Engine, rm *rules.Manager, status *PrometheusStatus, o *Options) *Handler { router := route.New() h := &Handler{ router: router, listenErrCh: make(chan error), quitCh: make(chan struct{}), reloadCh: make(chan struct{}), options: o, statusInfo: status, ruleManager: rm, queryEngine: qe, storage: st, apiV1: &v1.API{ QueryEngine: qe, Storage: st, }, apiLegacy: &legacy.API{ QueryEngine: qe, Storage: st, Now: model.Now, }, } if o.ExternalURL.Path != "" { // 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.ExternalURL.Path, http.StatusFound) }) router = router.WithPrefix(o.ExternalURL.Path) } instrf := prometheus.InstrumentHandlerFunc instrh := prometheus.InstrumentHandler router.Get("/", func(w http.ResponseWriter, r *http.Request) { http.Redirect(w, r, "/graph", http.StatusFound) }) router.Get("/graph", instrf("graph", h.graph)) router.Get("/status", instrf("status", h.status)) router.Get("/alerts", instrf("alerts", h.alerts)) router.Get("/version", instrf("version", h.version)) router.Get("/heap", instrf("heap", dumpHeap)) router.Get("/federate", instrf("federate", h.federation)) router.Get(o.MetricsPath, prometheus.Handler().ServeHTTP) h.apiLegacy.Register(router.WithPrefix("/api")) h.apiV1.Register(router.WithPrefix("/api/v1")) router.Get("/consoles/*filepath", instrf("consoles", h.consoles)) if o.UseLocalAssets { router.Get("/static/*filepath", instrf("static", route.FileServe("web/blob/static"))) } else { router.Get("/static/*filepath", instrh("static", blob.Handler{})) } if o.UserAssetsPath != "" { router.Get("/user/*filepath", instrf("user", route.FileServe(o.UserAssetsPath))) } if o.EnableQuit { router.Post("/-/quit", h.quit) } router.Post("/-/reload", h.reload) router.Get("/debug/*subpath", http.DefaultServeMux.ServeHTTP) router.Post("/debug/*subpath", http.DefaultServeMux.ServeHTTP) return h } // ListenError returns the receive-only channel that signals errors while starting the web server. func (h *Handler) ListenError() <-chan error { return h.listenErrCh } // 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 struct{} { return h.reloadCh } // Run serves the HTTP endpoints. func (h *Handler) Run() { log.Infof("Listening on %s", h.options.ListenAddress) h.listenErrCh <- http.ListenAndServe(h.options.ListenAddress, h.router) } func (h *Handler) alerts(w http.ResponseWriter, r *http.Request) { alerts := h.ruleManager.AlertingRules() alertsSorter := byAlertStateSorter{alerts: alerts} sort.Sort(alertsSorter) alertStatus := AlertStatus{ AlertingRules: alertsSorter.alerts, AlertStateToRowClass: map[rules.AlertState]string{ rules.StateInactive: "success", rules.StatePending: "warning", rules.StateFiring: "danger", }, } h.executeTemplate(w, "alerts", alertStatus) } func (h *Handler) consoles(w http.ResponseWriter, r *http.Request) { ctx := route.Context(r) 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 } 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] } data := struct { RawParams url.Values Params map[string]string Path string }{ RawParams: rawParams, Params: params, Path: strings.TrimLeft(name, "/"), } tmpl := template.NewTemplateExpander(string(text), "__console_"+name, data, model.Now(), h.queryEngine, h.options.ExternalURL.Path) 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", nil) } func (h *Handler) status(w http.ResponseWriter, r *http.Request) { h.statusInfo.mu.RLock() defer h.statusInfo.mu.RUnlock() h.executeTemplate(w, "status", struct { Status *PrometheusStatus Info map[string]string }{ Status: h.statusInfo, Info: version.Map, }) } func (h *Handler) version(w http.ResponseWriter, r *http.Request) { dec := json.NewEncoder(w) if err := dec.Encode(version.Map); 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) { fmt.Fprintf(w, "Reloading configuration file...") h.reloadCh <- struct{}{} } func (h *Handler) getTemplateFile(name string) (string, error) { if h.options.UseLocalAssets { file, err := ioutil.ReadFile(fmt.Sprintf("web/blob/templates/%s.html", name)) if err != nil { log.Errorf("Could not read %s template: %s", name, err) return "", err } return string(file), nil } file, err := blob.GetFile(blob.TemplateFiles, name+".html") if err != nil { log.Errorf("Could not read %s template: %s", name, err) return "", err } return string(file), nil } 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 (h *Handler) getTemplate(name string) (string, error) { baseTmpl, err := h.getTemplateFile("_base") if err != nil { return "", fmt.Errorf("error reading base template: %s", err) } pageTmpl, err := h.getTemplateFile(name) if err != nil { return "", fmt.Errorf("error reading page template %s: %s", name, err) } return baseTmpl + pageTmpl, nil } func tmplFuncs(consolesPath string, opts *Options) template_text.FuncMap { return template_text.FuncMap{ "since": time.Since, "consolesPath": func() string { return consolesPath }, "pathPrefix": func() string { return opts.ExternalURL.Path }, "stripLabels": func(lset model.LabelSet, labels ...model.LabelName) model.LabelSet { for _, ln := range labels { delete(lset, ln) } return lset }, "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 }, "healthToClass": func(th retrieval.TargetHealth) string { switch th { case retrieval.HealthUnknown: return "warning" case retrieval.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) 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(text, name, data, model.Now(), h.queryEngine, h.options.ExternalURL.Path) 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) } func dumpHeap(w http.ResponseWriter, r *http.Request) { target := fmt.Sprintf("/tmp/%d.heap", time.Now().Unix()) f, err := os.Create(target) if err != nil { log.Error("Could not dump heap: ", err) } fmt.Fprintf(w, "Writing to %s...", target) defer f.Close() pprof_runtime.WriteHeapProfile(f) fmt.Fprintf(w, "Done") } // AlertStatus bundles alerting rules and the mapping of alert states to row classes. type AlertStatus struct { AlertingRules []*rules.AlertingRule AlertStateToRowClass map[rules.AlertState]string } type byAlertStateSorter struct { alerts []*rules.AlertingRule } func (s byAlertStateSorter) Len() int { return len(s.alerts) } func (s byAlertStateSorter) Less(i, j int) bool { return s.alerts[i].State() > s.alerts[j].State() } func (s byAlertStateSorter) Swap(i, j int) { s.alerts[i], s.alerts[j] = s.alerts[j], s.alerts[i] }