VictoriaMetrics/app/vmalert/datasource/vm_prom_api.go
Aliaksandr Valialkin d6415b2572
all: consistently use 'any' instead of 'interface{}'
'any' type is supported starting from Go1.18. Let's consistently use it
instead of 'interface{}' type across the code base, since `any` is easier to read than 'interface{}'.
2024-07-10 00:23:26 +02:00

273 lines
8.2 KiB
Go

package datasource
import (
"encoding/json"
"flag"
"fmt"
"net/http"
"strconv"
"time"
"github.com/VictoriaMetrics/VictoriaMetrics/lib/bytesutil"
"github.com/valyala/fastjson"
)
var (
disablePathAppend = flag.Bool("remoteRead.disablePathAppend", false, "Whether to disable automatic appending of '/api/v1/query' path "+
"to the configured -datasource.url and -remoteRead.url")
disableStepParam = flag.Bool("datasource.disableStepParam", false, "Whether to disable adding 'step' param to the issued instant queries. "+
"This might be useful when using vmalert with datasources that do not support 'step' param for instant queries, like Google Managed Prometheus. "+
"It is not recommended to enable this flag if you use vmalert with VictoriaMetrics.")
)
type promResponse struct {
Status string `json:"status"`
ErrorType string `json:"errorType"`
Error string `json:"error"`
Data struct {
ResultType string `json:"resultType"`
Result json.RawMessage `json:"result"`
} `json:"data"`
// Stats supported by VictoriaMetrics since v1.90
Stats struct {
SeriesFetched *string `json:"seriesFetched,omitempty"`
} `json:"stats,omitempty"`
}
// see https://prometheus.io/docs/prometheus/latest/querying/api/#instant-queries
type promInstant struct {
// ms is populated after Unmarshal call
ms []Metric
}
// metrics returned parsed Metric slice
// Must be called only after Unmarshal
func (pi *promInstant) metrics() ([]Metric, error) {
return pi.ms, nil
}
var jsonParserPool fastjson.ParserPool
// Unmarshal unmarshals the given byte slice into promInstant
// It is using fastjson to reduce number of allocations compared to
// standard json.Unmarshal function.
// Response example:
//
// [{"metric":{"__name__":"up","job":"prometheus"},value": [ 1435781451.781,"1"]},
// {"metric":{"__name__":"up","job":"node"},value": [ 1435781451.781,"0"]}]
func (pi *promInstant) Unmarshal(b []byte) error {
p := jsonParserPool.Get()
defer jsonParserPool.Put(p)
v, err := p.ParseBytes(b)
if err != nil {
return err
}
rows, err := v.Array()
if err != nil {
return fmt.Errorf("cannot find the top-level array of result objects: %w", err)
}
pi.ms = make([]Metric, len(rows))
for i, row := range rows {
metric := row.Get("metric")
if metric == nil {
return fmt.Errorf("can't find `metric` object in %q", row)
}
labels := metric.GetObject()
r := &pi.ms[i]
r.Labels = make([]Label, 0, labels.Len())
labels.Visit(func(key []byte, v *fastjson.Value) {
lv, errLocal := v.StringBytes()
if errLocal != nil {
err = fmt.Errorf("error when parsing label value %q: %s", v, errLocal)
return
}
r.Labels = append(r.Labels, Label{
Name: string(key),
Value: string(lv),
})
})
if err != nil {
return fmt.Errorf("error when parsing `metric` object in %q: %w", row, err)
}
value := row.Get("value")
if value == nil {
return fmt.Errorf("can't find `value` object in %q", row)
}
sample := value.GetArray()
if len(sample) != 2 {
return fmt.Errorf("object `value` in %q should contain 2 values, but contains %d instead", row, len(sample))
}
r.Timestamps = []int64{sample[0].GetInt64()}
val, err := sample[1].StringBytes()
if err != nil {
return fmt.Errorf("error when parsing `value` object %q: %s", sample[1], err)
}
f, err := strconv.ParseFloat(bytesutil.ToUnsafeString(val), 64)
if err != nil {
return fmt.Errorf("error when parsing float64 from %s in %q: %w", sample[1], row, err)
}
r.Values = []float64{f}
}
return nil
}
type promRange struct {
Result []struct {
Labels map[string]string `json:"metric"`
TVs [][2]any `json:"values"`
} `json:"result"`
}
func (r promRange) metrics() ([]Metric, error) {
var result []Metric
for i, res := range r.Result {
var m Metric
for _, tv := range res.TVs {
f, err := strconv.ParseFloat(tv[1].(string), 64)
if err != nil {
return nil, fmt.Errorf("metric %v, unable to parse float64 from %s: %w", res, tv[1], err)
}
m.Values = append(m.Values, f)
m.Timestamps = append(m.Timestamps, int64(tv[0].(float64)))
}
if len(m.Values) < 1 || len(m.Timestamps) < 1 {
return nil, fmt.Errorf("metric %v contains no values", res)
}
m.Labels = nil
for k, v := range r.Result[i].Labels {
m.AddLabel(k, v)
}
result = append(result, m)
}
return result, nil
}
type promScalar [2]any
func (r promScalar) metrics() ([]Metric, error) {
var m Metric
f, err := strconv.ParseFloat(r[1].(string), 64)
if err != nil {
return nil, fmt.Errorf("metric %v, unable to parse float64 from %s: %w", r, r[1], err)
}
m.Values = append(m.Values, f)
m.Timestamps = append(m.Timestamps, int64(r[0].(float64)))
return []Metric{m}, nil
}
const (
statusSuccess, statusError = "success", "error"
rtVector, rtMatrix, rScalar = "vector", "matrix", "scalar"
)
func parsePrometheusResponse(req *http.Request, resp *http.Response) (res Result, err error) {
r := &promResponse{}
if err = json.NewDecoder(resp.Body).Decode(r); err != nil {
return res, fmt.Errorf("error parsing prometheus metrics for %s: %w", req.URL.Redacted(), err)
}
if r.Status == statusError {
return res, fmt.Errorf("response error, query: %s, errorType: %s, error: %s", req.URL.Redacted(), r.ErrorType, r.Error)
}
if r.Status != statusSuccess {
return res, fmt.Errorf("unknown status: %s, Expected success or error", r.Status)
}
var parseFn func() ([]Metric, error)
switch r.Data.ResultType {
case rtVector:
var pi promInstant
if err := pi.Unmarshal(r.Data.Result); err != nil {
return res, fmt.Errorf("unmarshal err %w; \n %#v", err, string(r.Data.Result))
}
parseFn = pi.metrics
case rtMatrix:
var pr promRange
if err := json.Unmarshal(r.Data.Result, &pr.Result); err != nil {
return res, err
}
parseFn = pr.metrics
case rScalar:
var ps promScalar
if err := json.Unmarshal(r.Data.Result, &ps); err != nil {
return res, err
}
parseFn = ps.metrics
default:
return res, fmt.Errorf("unknown result type %q", r.Data.ResultType)
}
ms, err := parseFn()
if err != nil {
return res, err
}
res = Result{Data: ms}
if r.Stats.SeriesFetched != nil {
intV, err := strconv.Atoi(*r.Stats.SeriesFetched)
if err != nil {
return res, fmt.Errorf("failed to convert stats.seriesFetched to int: %w", err)
}
res.SeriesFetched = &intV
}
return res, nil
}
func (s *VMStorage) setPrometheusInstantReqParams(r *http.Request, query string, timestamp time.Time) {
if s.appendTypePrefix {
r.URL.Path += "/prometheus"
}
if !*disablePathAppend {
r.URL.Path += "/api/v1/query"
}
q := r.URL.Query()
q.Set("time", timestamp.Format(time.RFC3339))
if !*disableStepParam && s.evaluationInterval > 0 { // set step as evaluationInterval by default
// always convert to seconds to keep compatibility with older
// Prometheus versions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1943
q.Set("step", fmt.Sprintf("%ds", int(s.evaluationInterval.Seconds())))
}
if !*disableStepParam && s.queryStep > 0 { // override step with user-specified value
// always convert to seconds to keep compatibility with older
// Prometheus versions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1943
q.Set("step", fmt.Sprintf("%ds", int(s.queryStep.Seconds())))
}
r.URL.RawQuery = q.Encode()
s.setPrometheusReqParams(r, query)
}
func (s *VMStorage) setPrometheusRangeReqParams(r *http.Request, query string, start, end time.Time) {
if s.appendTypePrefix {
r.URL.Path += "/prometheus"
}
if !*disablePathAppend {
r.URL.Path += "/api/v1/query_range"
}
q := r.URL.Query()
q.Add("start", start.Format(time.RFC3339))
q.Add("end", end.Format(time.RFC3339))
if s.evaluationInterval > 0 { // set step as evaluationInterval by default
// always convert to seconds to keep compatibility with older
// Prometheus versions. See https://github.com/VictoriaMetrics/VictoriaMetrics/issues/1943
q.Set("step", fmt.Sprintf("%ds", int(s.evaluationInterval.Seconds())))
}
r.URL.RawQuery = q.Encode()
s.setPrometheusReqParams(r, query)
}
func (s *VMStorage) setPrometheusReqParams(r *http.Request, query string) {
q := r.URL.Query()
for k, vs := range s.extraParams {
if q.Has(k) { // extraParams are prior to params in URL
q.Del(k)
}
for _, v := range vs {
q.Add(k, v)
}
}
q.Set("query", query)
r.URL.RawQuery = q.Encode()
}