/
stats_fetcher.go
104 lines (87 loc) · 3.17 KB
/
stats_fetcher.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package utils
import (
"encoding/json"
"fmt"
"sort"
"github.com/golang/glog"
)
type StatCounters map[string]int
type StatHistograms map[string][]float64
const (
// Path with filtering for ESPv2 stats.
ESpv2FiltersStatsPath = "/stats?format=json&usedonly&filter=http.ingress_http.(backend_auth|service_control|path_rewrite)"
)
// Stats is the struct to decode envoy admin json raw data.
type Stats struct {
Stat []StatsData `json:"stats"`
}
// StatsData is the struct to decode the stats data, which may include the
// metric name and value, and metrics' histogram.
type StatsData struct {
MetricName string `json:"name,omitempty"`
MetricValue float64 `json:"value,omitempty"`
Bar Histogram `json:"histograms,omitempty"`
}
// Histogram is the struct which is an optional part of StatsData.
type Histogram struct {
// Cq represents computed_quantiles.
Cq []ComputedQuantiles `json:"computed_quantiles,omitempty"`
// Sq represents supported_quantiles.
Sq []interface{} `json:"supported_quantiles,omitempty"`
}
// ComputedQuantiles is the struct to represent the computed quantile for each histogram.
type ComputedQuantiles struct {
Name string `json:"name"`
Values []Point `json:"values"`
}
// Point is the struct to decode the values of computed_quantiles.
type Point struct {
Cumulative float64 `json:"cumulative,omitempty"`
Interval float64 `json:"interval,omitempty"`
}
func FetchStats(adminPort uint16) (StatCounters, StatHistograms, error) {
glog.Infof("Fetching stats from envoy")
// Fetch from envoy admin.
statsUrl := fmt.Sprintf("http://localhost:%v%v", adminPort, ESpv2FiltersStatsPath)
_, statsResp, err := DoWithHeaders(statsUrl, "GET", "", nil)
if err != nil {
return nil, nil, fmt.Errorf("failed to fetch envoy stats: %v", err)
}
// Parse into our own structures (maps) for easy lookups.
var stats Stats
if err := json.Unmarshal(statsResp, &stats); err != nil {
return nil, nil, fmt.Errorf("fail to unmarshal respnse to Stats: %v", err)
}
counters := StatCounters{}
histograms := StatHistograms{}
for _, stat := range stats.Stat {
if metricName := stat.MetricName; metricName != "" {
counters[metricName] = int(stat.MetricValue)
continue
}
for _, cp := range stat.Bar.Cq {
if len(cp.Values) == 0 {
continue
}
sort.SliceStable(cp.Values, func(i, j int) bool { return cp.Values[i].Interval < cp.Values[j].Interval })
for _, v := range cp.Values {
histograms[cp.Name] = append(histograms[cp.Name], v.Cumulative)
}
}
}
glog.Infof("Fetched stats\n counters: %v\n histograms: %v", counters, histograms)
return counters, histograms, nil
}