package prometheus import ( "context" "errors" "fmt" "io/ioutil" "log" "net" "net/http" "net/url" "sync" "time" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/internal" "github.com/influxdata/telegraf/internal/tls" "github.com/influxdata/telegraf/plugins/inputs" ) const acceptHeader = `application/vnd.google.protobuf;proto=io.prometheus.client.MetricFamily;encoding=delimited;q=0.7,text/plain;version=0.0.4;q=0.3` type Prometheus struct { // An array of urls to scrape metrics from. URLs []string `toml:"urls"` // An array of Kubernetes services to scrape metrics from. KubernetesServices []string // Location of kubernetes config file KubeConfig string // Bearer Token authorization file path BearerToken string `toml:"bearer_token"` BearerTokenString string `toml:"bearer_token_string"` ResponseTimeout internal.Duration `toml:"response_timeout"` tls.ClientConfig client *http.Client // Should we scrape Kubernetes services for prometheus annotations MonitorPods bool `toml:"monitor_kubernetes_pods"` lock sync.Mutex kubernetesPods map[string]URLAndAddress cancel context.CancelFunc wg sync.WaitGroup } var sampleConfig = ` ## An array of urls to scrape metrics from. urls = ["http://localhost:9100/metrics"] ## An array of Kubernetes services to scrape metrics from. # kubernetes_services = ["http://my-service-dns.my-namespace:9100/metrics"] ## Kubernetes config file to create client from. # kube_config = "/path/to/kubernetes.config" ## Scrape Kubernetes pods for the following prometheus annotations: ## - prometheus.io/scrape: Enable scraping for this pod ## - prometheus.io/scheme: If the metrics endpoint is secured then you will need to ## set this to 'https' & most likely set the tls config. ## - prometheus.io/path: If the metrics path is not /metrics, define it with this annotation. ## - prometheus.io/port: If port is not 9102 use this annotation # monitor_kubernetes_pods = true ## Use bearer token for authorization. ('bearer_token' takes priority) # bearer_token = "/path/to/bearer/token" ## OR # bearer_token_string = "abc_123" ## Specify timeout duration for slower prometheus clients (default is 3s) # response_timeout = "3s" ## Optional TLS Config # tls_ca = /path/to/cafile # tls_cert = /path/to/certfile # tls_key = /path/to/keyfile ## Use TLS but skip chain & host verification # insecure_skip_verify = false ` func (p *Prometheus) SampleConfig() string { return sampleConfig } func (p *Prometheus) Description() string { return "Read metrics from one or many prometheus clients" } var ErrProtocolError = errors.New("prometheus protocol error") func (p *Prometheus) AddressToURL(u *url.URL, address string) *url.URL { host := address if u.Port() != "" { host = address + ":" + u.Port() } reconstructedURL := &url.URL{ Scheme: u.Scheme, Opaque: u.Opaque, User: u.User, Path: u.Path, RawPath: u.RawPath, ForceQuery: u.ForceQuery, RawQuery: u.RawQuery, Fragment: u.Fragment, Host: host, } return reconstructedURL } type URLAndAddress struct { OriginalURL *url.URL URL *url.URL Address string Tags map[string]string } func (p *Prometheus) GetAllURLs() (map[string]URLAndAddress, error) { allURLs := make(map[string]URLAndAddress, 0) for _, u := range p.URLs { URL, err := url.Parse(u) if err != nil { log.Printf("prometheus: Could not parse %s, skipping it. Error: %s", u, err.Error()) continue } allURLs[URL.String()] = URLAndAddress{URL: URL, OriginalURL: URL} } p.lock.Lock() defer p.lock.Unlock() // loop through all pods scraped via the prometheus annotation on the pods for k, v := range p.kubernetesPods { allURLs[k] = v } for _, service := range p.KubernetesServices { URL, err := url.Parse(service) if err != nil { return nil, err } resolvedAddresses, err := net.LookupHost(URL.Hostname()) if err != nil { log.Printf("prometheus: Could not resolve %s, skipping it. Error: %s", URL.Host, err.Error()) continue } for _, resolved := range resolvedAddresses { serviceURL := p.AddressToURL(URL, resolved) allURLs[serviceURL.String()] = URLAndAddress{ URL: serviceURL, Address: resolved, OriginalURL: URL, } } } return allURLs, nil } // Reads stats from all configured servers accumulates stats. // Returns one of the errors encountered while gather stats (if any). func (p *Prometheus) Gather(acc telegraf.Accumulator) error { if p.client == nil { client, err := p.createHTTPClient() if err != nil { return err } p.client = client } var wg sync.WaitGroup allURLs, err := p.GetAllURLs() if err != nil { return err } for _, URL := range allURLs { wg.Add(1) go func(serviceURL URLAndAddress) { defer wg.Done() acc.AddError(p.gatherURL(serviceURL, acc)) }(URL) } wg.Wait() return nil } func (p *Prometheus) createHTTPClient() (*http.Client, error) { tlsCfg, err := p.ClientConfig.TLSConfig() if err != nil { return nil, err } client := &http.Client{ Transport: &http.Transport{ TLSClientConfig: tlsCfg, DisableKeepAlives: true, }, Timeout: p.ResponseTimeout.Duration, } return client, nil } func (p *Prometheus) gatherURL(u URLAndAddress, acc telegraf.Accumulator) error { var req *http.Request var err error var uClient *http.Client if u.URL.Scheme == "unix" { path := u.URL.Query().Get("path") if path == "" { path = "/metrics" } req, err = http.NewRequest("GET", "http://localhost"+path, nil) // ignore error because it's been handled before getting here tlsCfg, _ := p.ClientConfig.TLSConfig() uClient = &http.Client{ Transport: &http.Transport{ TLSClientConfig: tlsCfg, DisableKeepAlives: true, Dial: func(network, addr string) (net.Conn, error) { c, err := net.Dial("unix", u.URL.Path) return c, err }, }, Timeout: p.ResponseTimeout.Duration, } } else { if u.URL.Path == "" { u.URL.Path = "/metrics" } req, err = http.NewRequest("GET", u.URL.String(), nil) } req.Header.Add("Accept", acceptHeader) if p.BearerToken != "" { token, err := ioutil.ReadFile(p.BearerToken) if err != nil { return err } req.Header.Set("Authorization", "Bearer "+string(token)) } else if p.BearerTokenString != "" { req.Header.Set("Authorization", "Bearer "+p.BearerTokenString) } var resp *http.Response if u.URL.Scheme != "unix" { resp, err = p.client.Do(req) } else { resp, err = uClient.Do(req) } if err != nil { return fmt.Errorf("error making HTTP request to %s: %s", u.URL, err) } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { return fmt.Errorf("%s returned HTTP status %s", u.URL, resp.Status) } body, err := ioutil.ReadAll(resp.Body) if err != nil { return fmt.Errorf("error reading body: %s", err) } metrics, err := Parse(body, resp.Header) if err != nil { return fmt.Errorf("error reading metrics for %s: %s", u.URL, err) } for _, metric := range metrics { tags := metric.Tags() // strip user and password from URL u.OriginalURL.User = nil tags["url"] = u.OriginalURL.String() if u.Address != "" { tags["address"] = u.Address } for k, v := range u.Tags { tags[k] = v } switch metric.Type() { case telegraf.Counter: acc.AddCounter(metric.Name(), metric.Fields(), tags, metric.Time()) case telegraf.Gauge: acc.AddGauge(metric.Name(), metric.Fields(), tags, metric.Time()) case telegraf.Summary: acc.AddSummary(metric.Name(), metric.Fields(), tags, metric.Time()) case telegraf.Histogram: acc.AddHistogram(metric.Name(), metric.Fields(), tags, metric.Time()) default: acc.AddFields(metric.Name(), metric.Fields(), tags, metric.Time()) } } return nil } // Start will start the Kubernetes scraping if enabled in the configuration func (p *Prometheus) Start(a telegraf.Accumulator) error { if p.MonitorPods { var ctx context.Context ctx, p.cancel = context.WithCancel(context.Background()) return p.start(ctx) } return nil } func (p *Prometheus) Stop() { if p.MonitorPods { p.cancel() } p.wg.Wait() } func init() { inputs.Add("prometheus", func() telegraf.Input { return &Prometheus{ ResponseTimeout: internal.Duration{Duration: time.Second * 3}, kubernetesPods: map[string]URLAndAddress{}, } }) }