telegraf/plugins/inputs/http_response/http_response.go

155 lines
3.7 KiB
Go

package http_response
import (
"errors"
"io"
"net/http"
"net/url"
"strings"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
// HTTPResponse struct
type HTTPResponse struct {
Address string
Body string
Method string
ResponseTimeout int
Headers map[string]string
FollowRedirects bool
}
// 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://github.com"
## Set response_timeout (default 5 seconds)
response_timeout = 5
## HTTP Request Method
method = "GET"
## HTTP Request Headers (all values must be strings)
[inputs.http_response.headers]
# Host = "github.com"
## Whether to follow redirects from the server (defaults to false)
follow_redirects = true
## Optional HTTP Request Body
body = '''
{'fake':'data'}
'''
`
// SampleConfig returns the plugin SampleConfig
func (h *HTTPResponse) SampleConfig() string {
return sampleConfig
}
// ErrRedirectAttempted indicates that a redirect occurred
var ErrRedirectAttempted = errors.New("redirect")
// CreateHttpClient creates an http client which will timeout at the specified
// timeout period and can follow redirects if specified
func CreateHttpClient(followRedirects bool, ResponseTimeout time.Duration) *http.Client {
client := &http.Client{
Timeout: time.Second * ResponseTimeout,
}
if followRedirects == false {
client.CheckRedirect = func(req *http.Request, via []*http.Request) error {
return ErrRedirectAttempted
}
}
return client
}
// CreateHeaders takes a map of header strings and puts them
// into a http.Header Object
func CreateHeaders(headers map[string]string) http.Header {
httpHeaders := make(http.Header)
for key := range headers {
httpHeaders.Add(key, headers[key])
}
return httpHeaders
}
// HTTPGather gathers all fields and returns any errors it encounters
func (h *HTTPResponse) HTTPGather() (map[string]interface{}, error) {
// Prepare fields
fields := make(map[string]interface{})
client := CreateHttpClient(h.FollowRedirects, time.Duration(h.ResponseTimeout))
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, err
}
request.Header = CreateHeaders(h.Headers)
// Start Timer
start := time.Now()
resp, err := client.Do(request)
if err != nil {
if h.FollowRedirects {
return nil, err
}
if urlError, ok := err.(*url.Error); ok &&
urlError.Err == ErrRedirectAttempted {
err = nil
} else {
return nil, err
}
}
fields["response_time"] = time.Since(start).Seconds()
fields["http_response_code"] = resp.StatusCode
return fields, nil
}
// Gather gets all metric fields and tags and returns any errors it encounters
func (h *HTTPResponse) Gather(acc telegraf.Accumulator) error {
// Set default values
if h.ResponseTimeout < 1 {
h.ResponseTimeout = 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
tags := map[string]string{"server": h.Address, "method": h.Method}
var fields map[string]interface{}
// Gather data
fields, 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{}
})
}