func push(job string, grouping map[string]string, pushURL string, g prometheus.Gatherer, method string) error {
if !strings.Contains(pushURL, "://") {
pushURL = "http://" + pushURL
}
if strings.HasSuffix(pushURL, "/") {
pushURL = pushURL[:len(pushURL)-1]
}
if strings.Contains(job, "/") {
return fmt.Errorf("job contains '/': %s", job)
}
urlComponents := []string{url.QueryEscape(job)}
for ln, lv := range grouping {
if !model.LabelNameRE.MatchString(ln) {
return fmt.Errorf("grouping label has invalid name: %s", ln)
}
if strings.Contains(lv, "/") {
return fmt.Errorf("value of grouping label %s contains '/': %s", ln, lv)
}
urlComponents = append(urlComponents, ln, lv)
}
pushURL = fmt.Sprintf("%s/metrics/job/%s", pushURL, strings.Join(urlComponents, "/"))
mfs, err := g.Gather()
if err != nil {
return err
}
buf := &bytes.Buffer{}
enc := expfmt.NewEncoder(buf, expfmt.FmtProtoDelim)
// Check for pre-existing grouping labels:
for _, mf := range mfs {
for _, m := range mf.GetMetric() {
for _, l := range m.GetLabel() {
if l.GetName() == "job" {
return fmt.Errorf("pushed metric %s (%s) already contains a job label", mf.GetName(), m)
}
if _, ok := grouping[l.GetName()]; ok {
return fmt.Errorf(
"pushed metric %s (%s) already contains grouping label %s",
mf.GetName(), m, l.GetName(),
)
}
}
}
enc.Encode(mf)
}
req, err := http.NewRequest(method, pushURL, buf)
if err != nil {
return err
}
req.Header.Set(contentTypeHeader, string(expfmt.FmtProtoDelim))
resp, err := http.DefaultClient.Do(req)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != 202 {
body, _ := ioutil.ReadAll(resp.Body) // Ignore any further error as this is for an error message only.
return fmt.Errorf("unexpected status code %d while pushing to %s: %s", resp.StatusCode, pushURL, body)
}
return nil
}
// HandlerFor returns an http.Handler for the provided Gatherer. The behavior
// of the Handler is defined by the provided HandlerOpts.
func HandlerFor(reg prometheus.Gatherer, opts HandlerOpts) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
mfs, err := reg.Gather()
if err != nil {
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error gathering metrics:", err)
}
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case ContinueOnError:
if len(mfs) == 0 {
http.Error(w, "No metrics gathered, last error:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
case HTTPErrorOnError:
http.Error(w, "An error has occurred during metrics gathering:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
contentType := expfmt.Negotiate(req.Header)
buf := getBuf()
defer giveBuf(buf)
writer, encoding := decorateWriter(req, buf, opts.DisableCompression)
enc := expfmt.NewEncoder(writer, contentType)
var lastErr error
for _, mf := range mfs {
if err := enc.Encode(mf); err != nil {
lastErr = err
if opts.ErrorLog != nil {
opts.ErrorLog.Println("error encoding metric family:", err)
}
switch opts.ErrorHandling {
case PanicOnError:
panic(err)
case ContinueOnError:
// Handled later.
case HTTPErrorOnError:
http.Error(w, "An error has occurred during metrics encoding:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
}
}
if closer, ok := writer.(io.Closer); ok {
closer.Close()
}
if lastErr != nil && buf.Len() == 0 {
http.Error(w, "No metrics encoded, last error:\n\n"+err.Error(), http.StatusInternalServerError)
return
}
header := w.Header()
header.Set(contentTypeHeader, string(contentType))
header.Set(contentLengthHeader, fmt.Sprint(buf.Len()))
if encoding != "" {
header.Set(contentEncodingHeader, encoding)
}
w.Write(buf.Bytes())
// TODO(beorn7): Consider streaming serving of metrics.
})
}