open-vault/helper/metricsutil/metricsutil.go

105 lines
2.6 KiB
Go

package metricsutil
import (
"bytes"
"encoding/json"
"fmt"
"github.com/armon/go-metrics"
"github.com/hashicorp/vault/sdk/logical"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/common/expfmt"
"strings"
)
const (
OpenMetricsMIMEType = "application/openmetrics-text"
)
const (
PrometheusMetricFormat = "prometheus"
)
type MetricsHelper struct {
inMemSink *metrics.InmemSink
PrometheusEnabled bool
}
func NewMetricsHelper(inMem *metrics.InmemSink, enablePrometheus bool) *MetricsHelper {
return &MetricsHelper{inMem, enablePrometheus}
}
func FormatFromRequest(req *logical.Request) string {
acceptHeaders := req.Headers["Accept"]
if len(acceptHeaders) > 0 {
acceptHeader := acceptHeaders[0]
if strings.HasPrefix(acceptHeader, OpenMetricsMIMEType) {
return "prometheus"
}
}
return ""
}
func (m *MetricsHelper) ResponseForFormat(format string) (*logical.Response, error) {
switch format {
case PrometheusMetricFormat:
return m.PrometheusResponse()
case "":
return m.GenericResponse()
default:
return nil, fmt.Errorf("metric response format \"%s\" unknown", format)
}
}
func (m *MetricsHelper) PrometheusResponse() (*logical.Response, error) {
if !m.PrometheusEnabled {
return &logical.Response{
Data: map[string]interface{}{
logical.HTTPContentType: "text/plain",
logical.HTTPRawBody: "prometheus is not enabled",
logical.HTTPStatusCode: 400,
},
}, nil
}
metricsFamilies, err := prometheus.DefaultGatherer.Gather()
if err != nil && len(metricsFamilies) == 0 {
return nil, fmt.Errorf("no prometheus metrics could be decoded: %s", err)
}
// Initialize a byte buffer.
buf := &bytes.Buffer{}
defer buf.Reset()
e := expfmt.NewEncoder(buf, expfmt.FmtText)
for _, mf := range metricsFamilies {
err := e.Encode(mf)
if err != nil {
return nil, fmt.Errorf("error during the encoding of metrics: %s", err)
}
}
return &logical.Response{
Data: map[string]interface{}{
logical.HTTPContentType: string(expfmt.FmtText),
logical.HTTPRawBody: buf.Bytes(),
logical.HTTPStatusCode: 200,
},
}, nil
}
func (m *MetricsHelper) GenericResponse() (*logical.Response, error) {
summary, err := m.inMemSink.DisplayMetrics(nil, nil)
if err != nil {
return nil, fmt.Errorf("error while fetching the in-memory metrics: %s", err)
}
content, err := json.Marshal(summary)
if err != nil {
return nil, fmt.Errorf("error while marshalling the in-memory metrics: %s", err)
}
return &logical.Response{
Data: map[string]interface{}{
logical.HTTPContentType: "application/json",
logical.HTTPRawBody: content,
logical.HTTPStatusCode: 200,
},
}, nil
}