package http_response import ( "errors" "fmt" "io" "io/ioutil" "log" "net" "net/http" "net/url" "regexp" "strconv" "strings" "time" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/internal" "github.com/influxdata/telegraf/plugins/inputs" ) // HTTPResponse struct type HTTPResponse struct { Address string Proxy string Body string Method string ResponseTimeout internal.Duration Headers map[string]string FollowRedirects bool ResponseStringMatch string // 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 compiledStringMatch *regexp.Regexp client *http.Client } // Description returns the plugin Description func (h *HTTPResponse) Description() string { return "HTTP/HTTPS request given an address a method and a timeout" } var sampleConfig = ` ## Server address (default http://localhost) # address = "http://localhost" ## Set http_proxy (telegraf uses the system wide proxy settings if it's is not set) # http_proxy = "http://localhost:8888" ## Set response_timeout (default 5 seconds) # response_timeout = "5s" ## HTTP Request Method # method = "GET" ## Whether to follow redirects from the server (defaults to false) # follow_redirects = false ## Optional HTTP Request Body # body = ''' # {'fake':'data'} # ''' ## Optional substring or regex match in body of the response # response_string_match = "\"service_status\": \"up\"" # response_string_match = "ok" # response_string_match = "\".*_status\".?:.?\"up\"" ## Optional SSL Config # ssl_ca = "/etc/telegraf/ca.pem" # ssl_cert = "/etc/telegraf/cert.pem" # ssl_key = "/etc/telegraf/key.pem" ## Use SSL but skip chain & host verification # insecure_skip_verify = false ## HTTP Request Headers (all values must be strings) # [inputs.http_response.headers] # Host = "github.com" ` // SampleConfig returns the plugin SampleConfig func (h *HTTPResponse) SampleConfig() string { return sampleConfig } // ErrRedirectAttempted indicates that a redirect occurred var ErrRedirectAttempted = errors.New("redirect") // Set the proxy. A configured proxy overwrites the system wide proxy. func getProxyFunc(http_proxy string) func(*http.Request) (*url.URL, error) { if http_proxy == "" { return http.ProxyFromEnvironment } proxyURL, err := url.Parse(http_proxy) if err != nil { return func(_ *http.Request) (*url.URL, error) { return nil, errors.New("bad proxy: " + err.Error()) } } return func(r *http.Request) (*url.URL, error) { return proxyURL, nil } } // CreateHttpClient creates an http client which will timeout at the specified // timeout period and can follow redirects if specified func (h *HTTPResponse) createHttpClient() (*http.Client, error) { tlsCfg, err := internal.GetTLSConfig( h.SSLCert, h.SSLKey, h.SSLCA, h.InsecureSkipVerify) if err != nil { return nil, err } client := &http.Client{ Transport: &http.Transport{ Proxy: getProxyFunc(h.Proxy), DisableKeepAlives: true, TLSClientConfig: tlsCfg, }, Timeout: h.ResponseTimeout.Duration, } if h.FollowRedirects == false { client.CheckRedirect = func(req *http.Request, via []*http.Request) error { return ErrRedirectAttempted } } return client, nil } func setResult(result_string string, fields map[string]interface{}, tags map[string]string) { result_codes := map[string]int{ "success": 0, "response_string_mismatch": 1, "body_read_error": 2, "connection_failed": 3, "timeout": 4, "dns_error": 5, } tags["result"] = result_string fields["result_type"] = result_string fields["result_code"] = result_codes[result_string] } func setError(err error, fields map[string]interface{}, tags map[string]string) error { if timeoutError, ok := err.(net.Error); ok && timeoutError.Timeout() { setResult("timeout", fields, tags) return timeoutError } urlErr, isUrlErr := err.(*url.Error) if !isUrlErr { return nil } opErr, isNetErr := (urlErr.Err).(*net.OpError) if isNetErr { switch e := (opErr.Err).(type) { case (*net.DNSError): setResult("dns_error", fields, tags) return e case (*net.ParseError): // Parse error has to do with parsing of IP addresses, so we // group it with address errors setResult("address_error", fields, tags) return e } } return nil } // HTTPGather gathers all fields and returns any errors it encounters func (h *HTTPResponse) httpGather() (map[string]interface{}, map[string]string, error) { // Prepare fields and tags fields := make(map[string]interface{}) tags := map[string]string{"server": h.Address, "method": h.Method} var body io.Reader if h.Body != "" { body = strings.NewReader(h.Body) } request, err := http.NewRequest(h.Method, h.Address, body) if err != nil { return nil, nil, err } for key, val := range h.Headers { request.Header.Add(key, val) if key == "Host" { request.Host = val } } // Start Timer start := time.Now() resp, err := h.client.Do(request) response_time := time.Since(start).Seconds() // If an error in returned, it means we are dealing with a network error, as // HTTP error codes do not generate errors in the net/http library if err != nil { // Log error log.Printf("D! Network error while polling %s: %s", h.Address, err.Error()) // Get error details netErr := setError(err, fields, tags) // If recognize the returnded error, get out if netErr != nil { return fields, tags, nil } // Any error not recognized by `set_error` is considered a "connection_failed" setResult("connection_failed", fields, tags) // If the error is a redirect we continue processing and log the HTTP code urlError, isUrlError := err.(*url.Error) if !h.FollowRedirects && isUrlError && urlError.Err == ErrRedirectAttempted { err = nil } else { // If the error isn't a timeout or a redirect stop // processing the request return fields, tags, nil } } if _, ok := fields["response_time"]; !ok { fields["response_time"] = response_time } // This function closes the response body, as // required by the net/http library defer func() { io.Copy(ioutil.Discard, resp.Body) resp.Body.Close() }() // Set log the HTTP response code tags["status_code"] = strconv.Itoa(resp.StatusCode) fields["http_response_code"] = resp.StatusCode // Check the response for a regex match. if h.ResponseStringMatch != "" { bodyBytes, err := ioutil.ReadAll(resp.Body) if err != nil { log.Printf("D! Failed to read body of HTTP Response : %s", err) setResult("body_read_error", fields, tags) fields["response_string_match"] = 0 return fields, tags, nil } if h.compiledStringMatch.Match(bodyBytes) { setResult("success", fields, tags) fields["response_string_match"] = 1 } else { setResult("response_string_mismatch", fields, tags) fields["response_string_match"] = 0 } } else { setResult("success", fields, tags) } return fields, tags, nil } // Gather gets all metric fields and tags and returns any errors it encounters func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error { // Compile the body regex if it exist if h.compiledStringMatch == nil { var err error h.compiledStringMatch, err = regexp.Compile(h.ResponseStringMatch) if err != nil { return fmt.Errorf("Failed to compile regular expression %s : %s", h.ResponseStringMatch, err) } } // Set default values if h.ResponseTimeout.Duration < time.Second { h.ResponseTimeout.Duration = time.Second * 5 } // Check send and expected string if h.Method == "" { h.Method = "GET" } if h.Address == "" { h.Address = "http://localhost" } addr, err := url.Parse(h.Address) if err != nil { return err } if addr.Scheme != "http" && addr.Scheme != "https" { return errors.New("Only http and https are supported") } // Prepare data var fields map[string]interface{} var tags map[string]string if h.client == nil { client, err := h.createHttpClient() if err != nil { return err } h.client = client } // Gather data fields, tags, err = h.httpGather() if err != nil { return err } // Add metrics acc.AddFields("http_response", fields, tags) return nil } func init() { inputs.Add("http_response", func() telegraf.Input { return &HTTPResponse{} }) }