a3fd1a5f3c
* Add accept header check for prometheus mime type * Fix small header filter bug. Add test
132 lines
3.4 KiB
Go
132 lines
3.4 KiB
Go
package metricsutil
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import (
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"bytes"
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"encoding/json"
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"fmt"
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"net/http"
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"strings"
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"github.com/armon/go-metrics"
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"github.com/hashicorp/vault/sdk/logical"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/common/expfmt"
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)
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const (
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OpenMetricsMIMEType = "application/openmetrics-text"
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PrometheusSchemaMIMEType = "prometheus/telemetry"
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// ErrorContentType is the content type returned by an error response.
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ErrorContentType = "text/plain"
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)
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const (
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PrometheusMetricFormat = "prometheus"
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)
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type MetricsHelper struct {
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inMemSink *metrics.InmemSink
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PrometheusEnabled bool
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}
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func NewMetricsHelper(inMem *metrics.InmemSink, enablePrometheus bool) *MetricsHelper {
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return &MetricsHelper{inMem, enablePrometheus}
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}
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func FormatFromRequest(req *logical.Request) string {
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acceptHeaders := req.Headers["Accept"]
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if len(acceptHeaders) > 0 {
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acceptHeader := acceptHeaders[0]
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if strings.HasPrefix(acceptHeader, OpenMetricsMIMEType) {
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return PrometheusMetricFormat
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}
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// Look for prometheus accept header
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for _, header := range acceptHeaders {
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if strings.Contains(header, PrometheusSchemaMIMEType) {
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return PrometheusMetricFormat
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}
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}
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}
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return ""
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}
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func (m *MetricsHelper) ResponseForFormat(format string) *logical.Response {
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switch format {
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case PrometheusMetricFormat:
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return m.PrometheusResponse()
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case "":
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return m.GenericResponse()
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default:
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return &logical.Response{
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Data: map[string]interface{}{
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logical.HTTPContentType: ErrorContentType,
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logical.HTTPRawBody: fmt.Sprintf("metric response format \"%s\" unknown", format),
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logical.HTTPStatusCode: http.StatusBadRequest,
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},
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}
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}
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}
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func (m *MetricsHelper) PrometheusResponse() *logical.Response {
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resp := &logical.Response{
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Data: map[string]interface{}{
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logical.HTTPContentType: ErrorContentType,
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logical.HTTPStatusCode: http.StatusBadRequest,
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},
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}
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if !m.PrometheusEnabled {
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resp.Data[logical.HTTPRawBody] = "prometheus is not enabled"
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return resp
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}
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metricsFamilies, err := prometheus.DefaultGatherer.Gather()
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if err != nil && len(metricsFamilies) == 0 {
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resp.Data[logical.HTTPRawBody] = fmt.Sprintf("no prometheus metrics could be decoded: %s", err)
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return resp
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}
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// Initialize a byte buffer.
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buf := &bytes.Buffer{}
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defer buf.Reset()
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e := expfmt.NewEncoder(buf, expfmt.FmtText)
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for _, mf := range metricsFamilies {
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err := e.Encode(mf)
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if err != nil {
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resp.Data[logical.HTTPRawBody] = fmt.Sprintf("error during the encoding of metrics: %s", err)
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return resp
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}
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}
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resp.Data[logical.HTTPContentType] = string(expfmt.FmtText)
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resp.Data[logical.HTTPRawBody] = buf.Bytes()
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resp.Data[logical.HTTPStatusCode] = http.StatusOK
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return resp
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}
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func (m *MetricsHelper) GenericResponse() *logical.Response {
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resp := &logical.Response{
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Data: map[string]interface{}{
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logical.HTTPContentType: ErrorContentType,
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logical.HTTPStatusCode: http.StatusBadRequest,
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},
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}
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summary, err := m.inMemSink.DisplayMetrics(nil, nil)
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if err != nil {
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resp.Data[logical.HTTPRawBody] = fmt.Sprintf("error while fetching the in-memory metrics: %s", err)
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return resp
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}
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content, err := json.Marshal(summary)
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if err != nil {
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resp.Data[logical.HTTPRawBody] = fmt.Sprintf("error while marshalling the in-memory metrics: %s", err)
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return resp
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}
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resp.Data[logical.HTTPContentType] = "application/json"
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resp.Data[logical.HTTPRawBody] = content
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resp.Data[logical.HTTPStatusCode] = http.StatusOK
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return resp
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}
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