From 44cab9f5e298d190c96a05b4119622232914ed82 Mon Sep 17 00:00:00 2001
From: "Masih H. Derkani" <m@derkani.org>
Date: Wed, 14 Dec 2022 16:31:57 +0000
Subject: [PATCH] Count HTTP delegated routing calls by method and return 501
 on `PUT`

Count the number of calls made to the HTTP delegated routing tagged by
method.

Explicitly return `501 Not Implemented` on `PUT` to
`/routing/v1/providers`. This is to identify that putting provider
records is not currently implemented by `cid.contact`.

Relates to:
- https://github.com/ipfs/specs/pull/337#discussion_r1047399812

Fixes #54
---
 delegated_translator.go | 15 ++++++++++++++-
 metrics/server.go       | 13 ++++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/delegated_translator.go b/delegated_translator.go
index df1b7f3..da2edef 100644
--- a/delegated_translator.go
+++ b/delegated_translator.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"encoding/json"
 	"io"
 	"net/http"
@@ -11,9 +12,12 @@ import (
 	"github.com/filecoin-project/index-provider/metadata"
 	"github.com/filecoin-project/storetheindex/api/v0/finder/model"
 	"github.com/filecoin-shipyard/indexstar/httpserver"
+	"github.com/filecoin-shipyard/indexstar/metrics"
 	"github.com/libp2p/go-libp2p/core/peer"
 	"github.com/multiformats/go-multiaddr"
 	"github.com/multiformats/go-multicodec"
+	"go.opencensus.io/stats"
+	"go.opencensus.io/tag"
 )
 
 const (
@@ -33,6 +37,10 @@ type delegatedTranslator struct {
 }
 
 func (dt *delegatedTranslator) find(w http.ResponseWriter, r *http.Request) {
+	_ = stats.RecordWithOptions(context.Background(),
+		stats.WithTags(tag.Insert(metrics.Method, r.Method)),
+		stats.WithMeasurements(metrics.HttpDelegatedRoutingMethod.M(1)))
+
 	// read out / close the request body.
 	_, err := io.ReadAll(r.Body)
 	_ = r.Body.Close()
@@ -42,6 +50,11 @@ func (dt *delegatedTranslator) find(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if r.Method == http.MethodPut {
+		http.Error(w, "", http.StatusNotImplemented)
+		return
+	}
+
 	h := w.Header()
 	h.Add("Access-Control-Allow-Origin", "*")
 	h.Add("Access-Control-Allow-Methods", "GET, PUT, OPTIONS")
@@ -64,7 +77,7 @@ func (dt *delegatedTranslator) find(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "", http.StatusInternalServerError)
 		return
 	}
-	rcode, resp := dt.be(r.Context(), "GET", findMethodDelegated, uri, []byte{})
+	rcode, resp := dt.be(r.Context(), http.MethodGet, findMethodDelegated, uri, []byte{})
 
 	if rcode != http.StatusOK {
 		http.Error(w, "", rcode)
diff --git a/metrics/server.go b/metrics/server.go
index ebe55a5..0b183a0 100644
--- a/metrics/server.go
+++ b/metrics/server.go
@@ -26,9 +26,10 @@ var (
 
 // Measures
 var (
-	FindLatency  = stats.Float64("indexstar/find/latency", "Time to respond to a find request", stats.UnitMilliseconds)
-	FindBackends = stats.Float64("indexstar/find/backends", "Backends reachd in a find request", stats.UnitDimensionless)
-	FindLoad     = stats.Int64("indexstar/find/load", "Amount of calls to find", stats.UnitDimensionless)
+	FindLatency                = stats.Float64("indexstar/find/latency", "Time to respond to a find request", stats.UnitMilliseconds)
+	FindBackends               = stats.Float64("indexstar/find/backends", "Backends reached in a find request", stats.UnitDimensionless)
+	FindLoad                   = stats.Int64("indexstar/find/load", "Amount of calls to find", stats.UnitDimensionless)
+	HttpDelegatedRoutingMethod = stats.Int64("indexstar/http_delegated_routing/load", "Amount of HTTP delegated routing calls by tagged method", stats.UnitDimensionless)
 )
 
 // Views
@@ -47,6 +48,11 @@ var (
 		Aggregation: view.Count(),
 		TagKeys:     []tag.Key{Method},
 	}
+	httpDelegRoutingMethodView = &view.View{
+		Measure:     HttpDelegatedRoutingMethod,
+		Aggregation: view.Count(),
+		TagKeys:     []tag.Key{Method},
+	}
 )
 
 // Start creates an HTTP router for serving metric info
@@ -56,6 +62,7 @@ func Start(views []*view.View) http.Handler {
 		findLatencyView,
 		findBackendView,
 		findLoadView,
+		httpDelegRoutingMethodView,
 	)
 	if err != nil {
 		log.Errorf("cannot register metrics default views: %s", err)