fix: set labels for linux memory metrics

Author: jamsinclair

CHANGELOG.md

@@ -12,6 +12,7 @@ project adheres to [Semantic Versioning](http://semver.org/).
 ### Changed
 
 - Don't add event listener to `process` if cluster module is not used.
+- fix: set labels for default memory metrics on linux
 
 ### Added
 

lib/metrics/osMemoryHeapLinux.js

@@ -34,11 +34,14 @@ function structureOutput(input) {
 module.exports = (registry, config = {}) => {
 	const registers = registry ? [registry] : undefined;
 	const namePrefix = config.prefix ? config.prefix : '';
+	const labels = config.labels ? config.labels : {};
+	const labelNames = Object.keys(labels);
 
 	const residentMemGauge = new Gauge({
 		name: namePrefix + PROCESS_RESIDENT_MEMORY,
 		help: 'Resident memory size in bytes.',
 		registers,
+		labelNames,
 		// Use this one metric's `collect` to set all metrics' values.
 		collect() {
 			try {
@@ -51,9 +54,9 @@ module.exports = (registry, config = {}) => {
 				const stat = fs.readFileSync('/proc/self/status', 'utf8');
 				const structuredOutput = structureOutput(stat);
 
-				residentMemGauge.set(structuredOutput.VmRSS);
-				virtualMemGauge.set(structuredOutput.VmSize);
-				heapSizeMemGauge.set(structuredOutput.VmData);
+				residentMemGauge.set(labels, structuredOutput.VmRSS);
+				virtualMemGauge.set(labels, structuredOutput.VmSize);
+				heapSizeMemGauge.set(labels, structuredOutput.VmData);
 			} catch {
 				// noop
 			}
@@ -63,11 +66,13 @@ module.exports = (registry, config = {}) => {
 		name: namePrefix + PROCESS_VIRTUAL_MEMORY,
 		help: 'Virtual memory size in bytes.',
 		registers,
+		labelNames,
 	});
 	const heapSizeMemGauge = new Gauge({
 		name: namePrefix + PROCESS_HEAP,
 		help: 'Process heap size in bytes.',
 		registers,
+		labelNames,
 	});
 };