package prometheus import ( "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/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 // An array of Kubernetes services to scrape metrics from. KubernetesServices []string // Bearer Token authorization file path BearerToken string `toml:"bearer_token"` ResponseTimeout internal.Duration `toml:"response_timeout"` // Path to CA file SSLCA string `toml:"ssl_ca"` // Path to host cert file SSLCert string `toml:"ssl_cert"` // Path to cert key file SSLKey string `toml:"ssl_key"` // Use SSL but skip chain & host verification InsecureSkipVerify bool client *http.Client } 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"] ## Use bearer token for authorization # bearer_token = /path/to/bearer/token ## Specify timeout duration for slower prometheus clients (default is 3s) # response_timeout = "3s" ## Optional SSL Config # ssl_ca = /path/to/cafile # ssl_cert = /path/to/certfile # ssl_key = /path/to/keyfile ## Use SSL 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) string { 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.String() } type UrlAndAddress struct { Url string Address string } func (p *Prometheus) GetAllURLs() ([]UrlAndAddress, error) { allUrls := make([]UrlAndAddress, 0) for _, url := range p.Urls { allUrls = append(allUrls, UrlAndAddress{Url: url}) } for _, service := range p.KubernetesServices { u, err := url.Parse(service) if err != nil { return nil, err } resolvedAddresses, err := net.LookupHost(u.Hostname()) if err != nil { log.Printf("prometheus: Could not resolve %s, skipping it. Error: %s", u.Host, err) continue } for _, resolved := range resolvedAddresses { serviceUrl := p.AddressToURL(u, resolved) allUrls = append(allUrls, UrlAndAddress{Url: serviceUrl, Address: resolved}) } } 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 } var tr = &http.Transport{ ResponseHeaderTimeout: time.Duration(3 * time.Second), } var client = &http.Client{ Transport: tr, Timeout: time.Duration(4 * time.Second), } func (p *Prometheus) createHttpClient() (*http.Client, error) { tlsCfg, err := internal.GetTLSConfig( p.SSLCert, p.SSLKey, p.SSLCA, p.InsecureSkipVerify) 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(url UrlAndAddress, acc telegraf.Accumulator) error { var req, err = http.NewRequest("GET", url.Url, nil) req.Header.Add("Accept", acceptHeader) var token []byte var resp *http.Response if p.BearerToken != "" { token, err = ioutil.ReadFile(p.BearerToken) if err != nil { return err } req.Header.Set("Authorization", "Bearer "+string(token)) } resp, err = p.client.Do(req) if err != nil { return fmt.Errorf("error making HTTP request to %s: %s", url.Url, err) } defer resp.Body.Close() if resp.StatusCode != http.StatusOK { return fmt.Errorf("%s returned HTTP status %s", url.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", url.Url, err) } // Add (or not) collected metrics for _, metric := range metrics { tags := metric.Tags() tags["url"] = url.Url if url.Address != "" { tags["address"] = url.Address } acc.AddFields(metric.Name(), metric.Fields(), tags, metric.Time()) } return nil } func init() { inputs.Add("prometheus", func() telegraf.Input { return &Prometheus{ResponseTimeout: internal.Duration{Duration: time.Second * 3}} }) }