From b2b6bec215edaaa0d7eb7d92bdc5cc15021e9fb2 Mon Sep 17 00:00:00 2001
From: cam-schultz <camschultz32@gmail.com>
Date: Fri, 2 Feb 2024 19:55:26 +0000
Subject: [PATCH] message relayer metrics error checking

---
 main/main.go                       |  9 ++++++++-
 relayer/message_relayer_metrics.go | 20 +++++++++++++++++---
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/main/main.go b/main/main.go
index 5ed5e99a..b42d0c06 100644
--- a/main/main.go
+++ b/main/main.go
@@ -147,7 +147,14 @@ func main() {
 
 	startMetricsServer(logger, gatherer, defaultMetricsPort)
 
-	metrics := relayer.NewMessageRelayerMetrics(registerer)
+	metrics, err := relayer.NewMessageRelayerMetrics(registerer)
+	if err != nil {
+		logger.Error(
+			"Failed to create message relayer metrics",
+			zap.Error(err),
+		)
+		panic(err)
+	}
 
 	// Initialize message creator passed down to relayers for creating app requests.
 	messageCreator, err := message.NewCreator(logger, registerer, "message_creator", constants.DefaultNetworkCompressionType, constants.DefaultNetworkMaximumInboundTimeout)
diff --git a/relayer/message_relayer_metrics.go b/relayer/message_relayer_metrics.go
index 93a6fb89..1ceb61d7 100644
--- a/relayer/message_relayer_metrics.go
+++ b/relayer/message_relayer_metrics.go
@@ -3,7 +3,15 @@
 
 package relayer
 
-import "github.com/prometheus/client_golang/prometheus"
+import (
+	"errors"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var (
+	ErrFailedToCreateMessageRelayerMetrics = errors.New("failed to create message relayer metrics")
+)
 
 type MessageRelayerMetrics struct {
 	successfulRelayMessageCount  *prometheus.CounterVec
@@ -11,7 +19,7 @@ type MessageRelayerMetrics struct {
 	failedRelayMessageCount      *prometheus.CounterVec
 }
 
-func NewMessageRelayerMetrics(registerer prometheus.Registerer) *MessageRelayerMetrics {
+func NewMessageRelayerMetrics(registerer prometheus.Registerer) (*MessageRelayerMetrics, error) {
 	successfulRelayMessageCount := prometheus.NewCounterVec(
 		prometheus.CounterOpts{
 			Name: "successful_relay_message_count",
@@ -28,6 +36,9 @@ func NewMessageRelayerMetrics(registerer prometheus.Registerer) *MessageRelayerM
 		},
 		[]string{"destination_chain_id", "source_chain_id", "source_subnet_id"},
 	)
+	if createSignedMessageLatencyMS == nil {
+		return nil, ErrFailedToCreateMessageRelayerMetrics
+	}
 	registerer.MustRegister(createSignedMessageLatencyMS)
 
 	failedRelayMessageCount := prometheus.NewCounterVec(
@@ -37,11 +48,14 @@ func NewMessageRelayerMetrics(registerer prometheus.Registerer) *MessageRelayerM
 		},
 		[]string{"destination_chain_id", "source_chain_id", "source_subnet_id", "failure_reason"},
 	)
+	if failedRelayMessageCount == nil {
+		return nil, ErrFailedToCreateMessageRelayerMetrics
+	}
 	registerer.MustRegister(failedRelayMessageCount)
 
 	return &MessageRelayerMetrics{
 		successfulRelayMessageCount:  successfulRelayMessageCount,
 		createSignedMessageLatencyMS: createSignedMessageLatencyMS,
 		failedRelayMessageCount:      failedRelayMessageCount,
-	}
+	}, nil
 }