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loki/pkg/querier/http.go

511 lines
15 KiB

package querier
import (
"context"
"net/http"
"strconv"
"time"
"github.com/go-kit/log"
"github.com/go-kit/log/level"
"github.com/gorilla/websocket"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/prometheus/model/labels"
"github.com/prometheus/prometheus/promql/parser"
"github.com/weaveworks/common/httpgrpc"
"github.com/weaveworks/common/middleware"
"github.com/grafana/dskit/tenant"
"github.com/grafana/loki/pkg/loghttp"
loghttp_legacy "github.com/grafana/loki/pkg/loghttp/legacy"
"github.com/grafana/loki/pkg/logql"
"github.com/grafana/loki/pkg/logql/syntax"
"github.com/grafana/loki/pkg/logqlmodel"
"github.com/grafana/loki/pkg/logqlmodel/stats"
index_stats "github.com/grafana/loki/pkg/storage/stores/index/stats"
"github.com/grafana/loki/pkg/util/httpreq"
util_log "github.com/grafana/loki/pkg/util/log"
"github.com/grafana/loki/pkg/util/marshal"
marshal_legacy "github.com/grafana/loki/pkg/util/marshal/legacy"
"github.com/grafana/loki/pkg/util/server"
serverutil "github.com/grafana/loki/pkg/util/server"
"github.com/grafana/loki/pkg/util/spanlogger"
util_validation "github.com/grafana/loki/pkg/util/validation"
"github.com/grafana/loki/pkg/validation"
)
const (
wsPingPeriod = 1 * time.Second
)
type QueryResponse struct {
ResultType parser.ValueType `json:"resultType"`
Result parser.Value `json:"result"`
}
//nolint // QurierAPI defines HTTP handler functions for the querier.
type QuerierAPI struct {
querier Querier
cfg Config
limits *validation.Overrides
engine *logql.Engine
}
// NewQuerierAPI returns an instance of the QuerierAPI.
func NewQuerierAPI(cfg Config, querier Querier, limits *validation.Overrides, logger log.Logger) *QuerierAPI {
engine := logql.NewEngine(cfg.Engine, querier, limits, logger)
return &QuerierAPI{
cfg: cfg,
limits: limits,
querier: querier,
engine: engine,
}
}
// RangeQueryHandler is a http.HandlerFunc for range queries.
func (q *QuerierAPI) RangeQueryHandler(w http.ResponseWriter, r *http.Request) {
request, err := loghttp.ParseRangeQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
ctx := r.Context()
if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
serverutil.WriteError(err, w)
return
}
params := logql.NewLiteralParams(
request.Query,
request.Start,
request.End,
request.Step,
request.Interval,
request.Direction,
request.Limit,
request.Shards,
)
query := q.engine.Query(params)
result, err := query.Exec(ctx)
if err != nil {
serverutil.WriteError(err, w)
return
}
if err := marshal.WriteQueryResponseJSON(result, w); err != nil {
serverutil.WriteError(err, w)
return
}
}
// InstantQueryHandler is a http.HandlerFunc for instant queries.
func (q *QuerierAPI) InstantQueryHandler(w http.ResponseWriter, r *http.Request) {
request, err := loghttp.ParseInstantQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
ctx := r.Context()
if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
serverutil.WriteError(err, w)
return
}
params := logql.NewLiteralParams(
request.Query,
request.Ts,
request.Ts,
0,
0,
request.Direction,
request.Limit,
request.Shards,
)
query := q.engine.Query(params)
result, err := query.Exec(ctx)
if err != nil {
serverutil.WriteError(err, w)
return
}
if err := marshal.WriteQueryResponseJSON(result, w); err != nil {
serverutil.WriteError(err, w)
return
}
}
// LogQueryHandler is a http.HandlerFunc for log only queries.
func (q *QuerierAPI) LogQueryHandler(w http.ResponseWriter, r *http.Request) {
request, err := loghttp.ParseRangeQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
request.Query, err = parseRegexQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
expr, err := syntax.ParseExpr(request.Query)
if err != nil {
serverutil.WriteError(err, w)
return
}
// short circuit metric queries
if _, ok := expr.(syntax.SampleExpr); ok {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, "legacy endpoints only support %s result type", logqlmodel.ValueTypeStreams), w)
return
}
ctx := r.Context()
if err := q.validateEntriesLimits(ctx, request.Query, request.Limit); err != nil {
serverutil.WriteError(err, w)
return
}
params := logql.NewLiteralParams(
request.Query,
request.Start,
request.End,
request.Step,
request.Interval,
request.Direction,
request.Limit,
request.Shards,
)
query := q.engine.Query(params)
result, err := query.Exec(ctx)
if err != nil {
serverutil.WriteError(err, w)
return
}
if err := marshal_legacy.WriteQueryResponseJSON(result, w); err != nil {
serverutil.WriteError(err, w)
return
}
}
// LabelHandler is a http.HandlerFunc for handling label queries.
func (q *QuerierAPI) LabelHandler(w http.ResponseWriter, r *http.Request) {
req, err := loghttp.ParseLabelQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
timer := prometheus.NewTimer(logql.QueryTime.WithLabelValues("labels"))
defer timer.ObserveDuration()
start := time.Now()
statsCtx, ctx := stats.NewContext(r.Context())
resp, err := q.querier.Label(r.Context(), req)
queueTime, _ := ctx.Value(httpreq.QueryQueueTimeHTTPHeader).(time.Duration)
resLength := 0
if resp != nil {
resLength = len(resp.Values)
}
// record stats about the label query
statResult := statsCtx.Result(time.Since(start), queueTime, resLength)
log := spanlogger.FromContext(ctx)
statResult.Log(level.Debug(log))
status := 200
if err != nil {
status, _ = server.ClientHTTPStatusAndError(err)
}
logql.RecordLabelQueryMetrics(ctx, log, *req.Start, *req.End, req.Name, strconv.Itoa(status), statResult)
if err != nil {
serverutil.WriteError(err, w)
return
}
if loghttp.GetVersion(r.RequestURI) == loghttp.VersionV1 {
err = marshal.WriteLabelResponseJSON(*resp, w)
} else {
err = marshal_legacy.WriteLabelResponseJSON(*resp, w)
}
if err != nil {
serverutil.WriteError(err, w)
return
}
}
// TailHandler is a http.HandlerFunc for handling tail queries.
func (q *QuerierAPI) TailHandler(w http.ResponseWriter, r *http.Request) {
upgrader := websocket.Upgrader{
CheckOrigin: func(r *http.Request) bool { return true },
}
logger := util_log.WithContext(r.Context(), util_log.Logger)
req, err := loghttp.ParseTailQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
req.Query, err = parseRegexQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
tenantID, err := tenant.TenantID(r.Context())
if err != nil {
level.Warn(logger).Log("msg", "error getting tenant id", "err", err)
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
conn, err := upgrader.Upgrade(w, r, nil)
if err != nil {
level.Error(logger).Log("msg", "Error in upgrading websocket", "err", err)
return
}
level.Info(logger).Log("msg", "starting to tail logs", "tenant", tenantID, "selectors", req.Query)
defer func() {
level.Info(logger).Log("msg", "ended tailing logs", "tenant", tenantID, "selectors", req.Query)
}()
defer func() {
if err := conn.Close(); err != nil {
level.Error(logger).Log("msg", "Error closing websocket", "err", err)
}
}()
tailer, err := q.querier.Tail(r.Context(), req)
if err != nil {
if err := conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseInternalServerErr, err.Error())); err != nil {
level.Error(logger).Log("msg", "Error connecting to ingesters for tailing", "err", err)
}
return
}
defer func() {
if err := tailer.close(); err != nil {
level.Error(logger).Log("msg", "Error closing Tailer", "err", err)
}
}()
ticker := time.NewTicker(wsPingPeriod)
defer ticker.Stop()
var response *loghttp_legacy.TailResponse
responseChan := tailer.getResponseChan()
closeErrChan := tailer.getCloseErrorChan()
doneChan := make(chan struct{})
go func() {
for {
_, _, err := conn.ReadMessage()
if err != nil {
if closeErr, ok := err.(*websocket.CloseError); ok {
if closeErr.Code == websocket.CloseNormalClosure {
break
}
level.Error(logger).Log("msg", "Error from client", "err", err)
break
} else if tailer.stopped {
return
} else {
level.Error(logger).Log("msg", "Unexpected error from client", "err", err)
break
}
}
}
doneChan <- struct{}{}
}()
for {
select {
case response = <-responseChan:
var err error
if loghttp.GetVersion(r.RequestURI) == loghttp.VersionV1 {
err = marshal.WriteTailResponseJSON(*response, conn)
} else {
err = marshal_legacy.WriteTailResponseJSON(*response, conn)
}
if err != nil {
level.Error(logger).Log("msg", "Error writing to websocket", "err", err)
if err := conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseInternalServerErr, err.Error())); err != nil {
level.Error(logger).Log("msg", "Error writing close message to websocket", "err", err)
}
return
}
case err := <-closeErrChan:
level.Error(logger).Log("msg", "Error from iterator", "err", err)
if err := conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseInternalServerErr, err.Error())); err != nil {
level.Error(logger).Log("msg", "Error writing close message to websocket", "err", err)
}
return
case <-ticker.C:
// This is to periodically check whether connection is active, useful to clean up dead connections when there are no entries to send
if err := conn.WriteMessage(websocket.PingMessage, nil); err != nil {
level.Error(logger).Log("msg", "Error writing ping message to websocket", "err", err)
if err := conn.WriteMessage(websocket.CloseMessage, websocket.FormatCloseMessage(websocket.CloseInternalServerErr, err.Error())); err != nil {
level.Error(logger).Log("msg", "Error writing close message to websocket", "err", err)
}
return
}
case <-doneChan:
return
}
}
}
// SeriesHandler returns the list of time series that match a certain label set.
// See https://prometheus.io/docs/prometheus/latest/querying/api/#finding-series-by-label-matchers
func (q *QuerierAPI) SeriesHandler(w http.ResponseWriter, r *http.Request) {
req, err := loghttp.ParseAndValidateSeriesQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
timer := prometheus.NewTimer(logql.QueryTime.WithLabelValues("series"))
defer timer.ObserveDuration()
start := time.Now()
statsCtx, ctx := stats.NewContext(r.Context())
resp, err := q.querier.Series(r.Context(), req)
queueTime, _ := ctx.Value(httpreq.QueryQueueTimeHTTPHeader).(time.Duration)
resLength := 0
if resp != nil {
resLength = len(resp.Series)
}
// record stats about the label query
statResult := statsCtx.Result(time.Since(start), queueTime, resLength)
log := spanlogger.FromContext(ctx)
statResult.Log(level.Debug(log))
status := 200
if err != nil {
status, _ = server.ClientHTTPStatusAndError(err)
}
logql.RecordSeriesQueryMetrics(ctx, log, req.Start, req.End, req.Groups, strconv.Itoa(status), statResult)
if err != nil {
serverutil.WriteError(err, w)
return
}
err = marshal.WriteSeriesResponseJSON(*resp, w)
if err != nil {
serverutil.WriteError(err, w)
return
}
}
// IndexStatsHandler queries the index for the data statistics related to a query
func (q *QuerierAPI) IndexStatsHandler(w http.ResponseWriter, r *http.Request) {
req, err := loghttp.ParseIndexStatsQuery(r)
if err != nil {
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
// TODO(owen-d): log metadata, record stats?
resp, err := q.querier.IndexStats(r.Context(), req)
if resp == nil {
// Some stores don't implement this
resp = &index_stats.Stats{}
}
if err != nil {
serverutil.WriteError(err, w)
return
}
err = marshal.WriteIndexStatsResponseJSON(resp, w)
if err != nil {
serverutil.WriteError(err, w)
return
}
}
// parseRegexQuery parses regex and query querystring from httpRequest and returns the combined LogQL query.
// This is used only to keep regexp query string support until it gets fully deprecated.
func parseRegexQuery(httpRequest *http.Request) (string, error) {
query := httpRequest.Form.Get("query")
regexp := httpRequest.Form.Get("regexp")
if regexp != "" {
expr, err := syntax.ParseLogSelector(query, true)
if err != nil {
return "", err
}
newExpr, err := syntax.AddFilterExpr(expr, labels.MatchRegexp, "", regexp)
if err != nil {
return "", err
}
query = newExpr.String()
}
return query, nil
}
func (q *QuerierAPI) validateEntriesLimits(ctx context.Context, query string, limit uint32) error {
tenantIDs, err := tenant.TenantIDs(ctx)
if err != nil {
return httpgrpc.Errorf(http.StatusBadRequest, err.Error())
}
expr, err := syntax.ParseExpr(query)
if err != nil {
return err
}
// entry limit does not apply to metric queries.
if _, ok := expr.(syntax.SampleExpr); ok {
return nil
}
maxEntriesLimit := util_validation.SmallestPositiveNonZeroIntPerTenant(tenantIDs, q.limits.MaxEntriesLimitPerQuery)
if int(limit) > maxEntriesLimit && maxEntriesLimit != 0 {
return httpgrpc.Errorf(http.StatusBadRequest,
"max entries limit per query exceeded, limit > max_entries_limit (%d > %d)", limit, maxEntriesLimit)
}
return nil
}
// WrapQuerySpanAndTimeout applies a context deadline and a span logger to a query call.
//
// The timeout is based on the per-tenant query timeout configuration.
func WrapQuerySpanAndTimeout(call string, q *QuerierAPI) middleware.Interface {
return middleware.Func(func(next http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
log, ctx := spanlogger.New(req.Context(), call)
userID, err := tenant.TenantID(ctx)
if err != nil {
level.Error(log).Log("msg", "couldn't fetch tenantID", "err", err)
serverutil.WriteError(httpgrpc.Errorf(http.StatusBadRequest, err.Error()), w)
return
}
// Enforce the query timeout while querying backends
queryTimeout := q.limits.QueryTimeout(userID)
// TODO: remove this clause once we remove the deprecated query-timeout flag.
if q.cfg.QueryTimeout != 0 { // querier YAML configuration.
level.Warn(log).Log("msg", "deprecated querier:query_timeout YAML configuration identified. Please migrate to limits:query_timeout instead.", "call", "WrapQuerySpanAndTimeout")
queryTimeout = q.cfg.QueryTimeout
}
_, cancel := context.WithDeadline(ctx, time.Now().Add(queryTimeout))
defer cancel()
next.ServeHTTP(w, req)
})
})
}