src/go/plugin/go.d/modules/powerdns_recursor/collect.go
// SPDX-License-Identifier: GPL-3.0-or-later
package powerdns_recursor
import (
"errors"
"strconv"
"github.com/netdata/netdata/go/plugins/plugin/go.d/pkg/web"
)
const (
urlPathLocalStatistics = "/api/v1/servers/localhost/statistics"
)
func (r *Recursor) collect() (map[string]int64, error) {
statistics, err := r.scrapeStatistics()
if err != nil {
return nil, err
}
collected := make(map[string]int64)
r.collectStatistics(collected, statistics)
if !isPowerDNSRecursorMetrics(collected) {
return nil, errors.New("returned metrics aren't PowerDNS Recursor metrics")
}
return collected, nil
}
func isPowerDNSRecursorMetrics(collected map[string]int64) bool {
// PowerDNS Authoritative Server has same endpoint and returns data in the same format.
_, ok1 := collected["over-capacity-drops"]
_, ok2 := collected["tcp-questions"]
return ok1 && ok2
}
func (r *Recursor) collectStatistics(collected map[string]int64, statistics statisticMetrics) {
for _, s := range statistics {
// https://doc.powerdns.com/authoritative/http-api/statistics.html#statisticitem
if s.Type != "StatisticItem" {
continue
}
value, ok := s.Value.(string)
if !ok {
r.Debugf("%s value (%v) unexpected type: want=string, got=%T.", s.Name, s.Value, s.Value)
continue
}
v, err := strconv.ParseInt(value, 10, 64)
if err != nil {
r.Debugf("%s value (%v) parse error: %v", s.Name, s.Value, err)
continue
}
collected[s.Name] = v
}
}
func (r *Recursor) scrapeStatistics() ([]statisticMetric, error) {
req, _ := web.NewHTTPRequestWithPath(r.RequestConfig, urlPathLocalStatistics)
var stats statisticMetrics
if err := web.DoHTTP(r.httpClient).RequestJSON(req, &stats); err != nil {
return nil, err
}
return stats, nil
}