app/vmagent: follow-up after 2b22aa1537

- Document the change at docs/CHANGELOG.md
- Move auth token parsing from app/vmagent/opentsdbhttp/ to app/vmagent/main.go,
  since it must be parsed only when multitenancy support is enabled at vmagent side.
  See https://docs.victoriametrics.com/vmagent.html#multitenancy

app/vmagent/main.go

@@ -114,10 +114,12 @@ func main() {
 		graphiteServer = graphiteserver.MustStart(*graphiteListenAddr, graphite.InsertHandler)
 	}
 	if len(*opentsdbListenAddr) > 0 {
-		opentsdbServer = opentsdbserver.MustStart(*opentsdbListenAddr, opentsdb.InsertHandler, opentsdbhttp.InsertHandler)
+		httpInsertHandler := getOpenTSDBHTTPInsertHandler()
+		opentsdbServer = opentsdbserver.MustStart(*opentsdbListenAddr, opentsdb.InsertHandler, httpInsertHandler)
 	}
 	if len(*opentsdbHTTPListenAddr) > 0 {
-		opentsdbhttpServer = opentsdbhttpserver.MustStart(*opentsdbHTTPListenAddr, opentsdbhttp.InsertHandler)
+		httpInsertHandler := getOpenTSDBHTTPInsertHandler()
+		opentsdbhttpServer = opentsdbhttpserver.MustStart(*opentsdbHTTPListenAddr, httpInsertHandler)
 	}
 
 	promscrape.Init(remotewrite.Push)
@@ -159,6 +161,40 @@ func main() {
 	logger.Infof("successfully stopped vmagent in %.3f seconds", time.Since(startTime).Seconds())
 }
 
+func getOpenTSDBHTTPInsertHandler() func(req *http.Request) error {
+	if !remotewrite.MultitenancyEnabled() {
+		return func(req *http.Request) error {
+			path := strings.Replace(req.URL.Path, "//", "/", -1)
+			if path != "/api/put" {
+				return fmt.Errorf("unsupported path requested: %q; expecting '/api/put'", path)
+			}
+			return opentsdbhttp.InsertHandler(nil, req)
+		}
+	}
+	return func(req *http.Request) error {
+		path := strings.Replace(req.URL.Path, "//", "/", -1)
+		at, err := getAuthTokenFromPath(path)
+		if err != nil {
+			return fmt.Errorf("cannot obtain auth token from path %q: %w", path, err)
+		}
+		return opentsdbhttp.InsertHandler(at, req)
+	}
+}
+
+func getAuthTokenFromPath(path string) (*auth.Token, error) {
+	p, err := httpserver.ParsePath(path)
+	if err != nil {
+		return nil, fmt.Errorf("cannot parse multitenant path: %w", err)
+	}
+	if p.Prefix != "insert" {
+		return nil, fmt.Errorf(`unsupported multitenant prefix: %q; expected "insert"`, p.Prefix)
+	}
+	if p.Suffix != "opentsdb/api/put" {
+		return nil, fmt.Errorf("unsupported path requested: %q; expecting 'opentsdb/api/put'", p.Suffix)
+	}
+	return auth.NewToken(p.AuthToken)
+}
+
 func requestHandler(w http.ResponseWriter, r *http.Request) bool {
 	if r.URL.Path == "/" {
 		if r.Method != "GET" {

app/vmagent/opentsdbhttp/request_handler.go

@@ -1,15 +1,11 @@
 package opentsdbhttp
 
 import (
-	"errors"
-	"fmt"
 	"net/http"
-	"strings"
 
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmagent/common"
 	"github.com/VictoriaMetrics/VictoriaMetrics/app/vmagent/remotewrite"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/auth"
-	"github.com/VictoriaMetrics/VictoriaMetrics/lib/httpserver"
 	"github.com/VictoriaMetrics/VictoriaMetrics/lib/prompbmarshal"
 	parserCommon "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/common"
 	parser "github.com/VictoriaMetrics/VictoriaMetrics/lib/protoparser/opentsdbhttp"
@@ -24,17 +20,7 @@ var (
 
 // InsertHandler processes HTTP OpenTSDB put requests.
 // See http://opentsdb.net/docs/build/html/api_http/put.html
-func InsertHandler(req *http.Request) error {
+func InsertHandler(at *auth.Token, req *http.Request) error {
-	path := strings.Replace(req.URL.Path, "//", "/", -1)
-	p, err := httpserver.ParsePath(path)
-	if err != nil {
-		// Cannot parse multitenant path. Skip it - probably it will be parsed later.
-		return err
-	}
-	if p.Prefix != "insert" {
-		return errors.New(fmt.Sprintf(`unsupported multitenant prefix: %q; expected "insert"`, p.Prefix))
-	}
-	at, err := auth.NewToken(p.AuthToken)
 	extraLabels, err := parserCommon.GetExtraLabels(req)
 	if err != nil {
 		return err

docs/CHANGELOG.md

@@ -23,6 +23,7 @@ The following tip changes can be tested by building VictoriaMetrics components f
 
 * FEATURE: return shorter error messages to Grafana and to other clients requesting [/api/v1/query](https://docs.victoriametrics.com/keyConcepts.html#instant-query) and [/api/v1/query_range](https://docs.victoriametrics.com/keyConcepts.html#range-query) endpoints. This should simplify reading these errors by humans. The long error message with full context is still written to logs.
 * FEATURE: add the ability to fine-tune the number of points, which can be generated per each matching time series during [subquery](https://docs.victoriametrics.com/MetricsQL.html#subqueries) evaluation. This can be done with the `-search.maxPointsSubqueryPerTimeseries` command-line flag. See [this feature request](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/2922).
+* FEATURE: [vmagent](https://docs.victoriametrics.com/vmagent.html): add ability to accept [multitenant](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html#multitenancy) data via OpenTSDB `/api/put` protocol at `/insert/<tenantID>/opentsdb/api/put` http endpoint if [multitenant support](https://docs.victoriametrics.com/vmagent.html#multitenancy) is enabled at `vmagent`. Thanks to @chengjianyun for [the pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/3015).
 * FEATURE: [monitoring](https://docs.victoriametrics.com/#monitoring): expose `vm_hourly_series_limit_max_series`, `vm_hourly_series_limit_current_series`, `vm_daily_series_limit_max_series` and `vm_daily_series_limit_current_series` metrics when `-search.maxHourlySeries` or `-search.maxDailySeries` limits are set. This allows alerting when the number of unique series reaches the configured limits. See [these docs](https://docs.victoriametrics.com/#cardinality-limiter) for details.
 * FEATURE: [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html): reduce the amounts of logging at `vmstorage` when `vmselect` connects/disconnects to `vmstorage`.
 * FEATURE: [VictoriaMetrics cluster](https://docs.victoriametrics.com/Cluster-VictoriaMetrics.html): improve performance for heavy queries on systems with many CPU cores.