feat: add event filter and metrics options to systemd example config

extra/example.conf

@@ -153,6 +153,14 @@ ROOT_SECRET_ACCESS_KEY=
 # specified, all configured bucket events will be sent to the webhook.
 #VGW_EVENT_WEBHOOK_URL=
 
+# Bucket events can be filtered for any of the above event types. The
+# VGW_EVENT_FILTER option specifies a config file that contains the event
+# filter rules. The event filter rules are used to determine which events are
+# sent to the configured event services. Run:
+# versitygw utils gen-event-filter-config --path .
+# to generate a default rules file "event_config.json" in the current directory.
+#VGW_EVENT_FILTER=
+
 #######################
 # Debug / Diagnostics #
 #######################
@@ -228,6 +236,29 @@ ROOT_SECRET_ACCESS_KEY=
 #VGW_IAM_CACHE_TTL=120
 #VGW_IAM_CACHE_PRUNE=3600
 
+###########
+# Metrics #
+###########
+
+# The metrics service name is a tag that is added to all metrics to help
+# identify the source of the metrics. This is especially useful when multiple
+# gateways are running. The default is the hostname of the system.
+#VGW_METRICS_SERVICE_NAME=$HOSTNAME
+
+# The metrics service will send metrics to the configured statsd servers. The
+# servers are specified as a comma separated list of host:port pairs. The
+# default is to not send metrics to any statsd servers. The gateway uses
+# InfluxDB flavor of statsd metrics tags for the StatsD metrics type.
+#VGW_METRICS_STATSD_SERVERS=
+
+# The metrics service will send metrics to the configured dogstatsd servers.
+# The servers are specified as a comma separated list of host:port pairs. The
+# default is to not send metrics to any dogstatsd servers. Generally
+# DataDog recommends installing a local agent to collect metrics and forward
+# them to the DataDog service. In this case the option value would be the
+# local agent address: 127.0.0.1:8125.
+#VGW_METRICS_DOGSTATS_SERVERS=
+
 ######################################
 # VersityGW Backend Specific Options #
 ######################################