From 6b72246fe6f0e8fec5e1310550561e6ba07a93fb Mon Sep 17 00:00:00 2001
From: Bryan Boreham <bjboreham@gmail.com>
Date: Thu, 26 Mar 2020 19:01:12 +0000
Subject: [PATCH] fix (multitenant collector): Use consistent report timestamp

Previously the code called `time.Now()` in two different places so the
timestamps didn't match. Now we use the timestamp of the report itself.

Add the collector's local time to the report if it didn't have one.
---
 app/collector.go                   | 1 +
 app/multitenant/aws_collector.go   | 2 +-
 app/multitenant/billing_emitter.go | 2 +-
 app/router.go                      | 4 ++++
 4 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/app/collector.go b/app/collector.go
index f59f6f75f..a495b055a 100644
--- a/app/collector.go
+++ b/app/collector.go
@@ -348,6 +348,7 @@ func replay(a Adder, timestamps []time.Time, reports []report.Report) {
 	due := time.Now()
 	for {
 		for i, r := range reports {
+			r.TS = due
 			a.Add(nil, r, nil)
 			due = due.Add(delays[i])
 			delay := due.Sub(time.Now())
diff --git a/app/multitenant/aws_collector.go b/app/multitenant/aws_collector.go
index 0e84bdba1..f3a9ef6ba 100644
--- a/app/multitenant/aws_collector.go
+++ b/app/multitenant/aws_collector.go
@@ -538,7 +538,7 @@ func (c *awsCollector) Add(ctx context.Context, rep report.Report, buf []byte) e
 	}
 
 	// first, put the report on s3
-	rowKey, colKey := calculateDynamoKeys(userid, time.Now())
+	rowKey, colKey := calculateDynamoKeys(userid, rep.TS)
 	reportKey, err := calculateReportKey(rowKey, colKey)
 	if err != nil {
 		return err
diff --git a/app/multitenant/billing_emitter.go b/app/multitenant/billing_emitter.go
index ba0919b5e..6f5cb5d5c 100644
--- a/app/multitenant/billing_emitter.go
+++ b/app/multitenant/billing_emitter.go
@@ -59,7 +59,7 @@ func (e *BillingEmitter) Add(ctx context.Context, rep report.Report, buf []byte)
 		// proceeding.
 		return err
 	}
-	rowKey, colKey := calculateDynamoKeys(userID, now)
+	rowKey, colKey := calculateDynamoKeys(userID, rep.TS)
 
 	interval := e.reportInterval(rep)
 	// Cache the last-known value of interval for this user, and use
diff --git a/app/router.go b/app/router.go
index 24bcf1749..73a2b1954 100644
--- a/app/router.go
+++ b/app/router.go
@@ -148,6 +148,10 @@ func RegisterReportPostHandler(a Adder, router *mux.Router) {
 			buf, _ = rpt.WriteBinary()
 		}
 
+		// If it didn't come in with a timestamp, give it one now
+		if rpt.TS.IsZero() {
+			rpt.TS = time.Now().UTC()
+		}
 		if err := a.Add(ctx, *rpt, buf.Bytes()); err != nil {
 			log.Errorf("Error Adding report: %v", err)
 			respondWith(w, http.StatusInternalServerError, err)