From 82b837275dde7a0227619b02fa6f61dcfc820b1c Mon Sep 17 00:00:00 2001
From: Alex K <8418476+fearful-symmetry@users.noreply.github.com>
Date: Tue, 17 Nov 2020 07:47:59 -0800
Subject: [PATCH] Trim down beat name if it's longer than 15 characters
 (#22550)

* Trim down beat name if it's longer than 15 characters

* add OS guard, changelog
---
 CHANGELOG.next.asciidoc         | 1 +
 libbeat/cmd/instance/metrics.go | 6 ++++++
 2 files changed, 7 insertions(+)

diff --git a/CHANGELOG.next.asciidoc b/CHANGELOG.next.asciidoc
index 65e2dbe017d..cdf8d58d31c 100644
--- a/CHANGELOG.next.asciidoc
+++ b/CHANGELOG.next.asciidoc
@@ -434,6 +434,7 @@ https://github.com/elastic/beats/compare/v7.0.0-alpha2...master[Check the HEAD d
 - Add interval information to `monitor` metricset in azure. {pull}22152[22152]
 - Change Session ID type from int to string {pull}22359[22359]
 - Fix filesystem types on Windows in filesystem metricset. {pull}22531[22531]
+- Fix failiures caused by custom beat names with more than 15 characters {pull}22550[22550]
 
 *Packetbeat*
 
diff --git a/libbeat/cmd/instance/metrics.go b/libbeat/cmd/instance/metrics.go
index 24d3d12e3e1..2e727446d5d 100644
--- a/libbeat/cmd/instance/metrics.go
+++ b/libbeat/cmd/instance/metrics.go
@@ -43,6 +43,12 @@ func init() {
 func setupMetrics(name string) error {
 	monitoring.NewFunc(systemMetrics, "cpu", reportSystemCPUUsage, monitoring.Report)
 
+	//if the beat name is longer than 15 characters, truncate it so we don't fail process checks later on
+	// On *nix, the process name comes from /proc/PID/stat, which uses a comm value of 16 bytes, plus the null byte
+	if (runtime.GOOS == "linux" || runtime.GOOS == "darwin") && len(name) > 15 {
+		name = name[:15]
+	}
+
 	beatProcessStats = &process.Stats{
 		Procs:        []string{name},
 		EnvWhitelist: nil,