From 4c1285cf7a30b4fff20563488e156541e738f28b Mon Sep 17 00:00:00 2001
From: Sebastian Spaink <sspaink@influxdata.com>
Date: Wed, 15 Jun 2022 11:26:32 -0500
Subject: [PATCH] fix: backwards compatible support telegraf *filters* config

---
 cmd/telegraf/telegraf.go | 37 ++++++++++++++++++++++++++++++++-----
 1 file changed, 32 insertions(+), 5 deletions(-)

diff --git a/cmd/telegraf/telegraf.go b/cmd/telegraf/telegraf.go
index f8c61c33ce015..8990769954a25 100644
--- a/cmd/telegraf/telegraf.go
+++ b/cmd/telegraf/telegraf.go
@@ -449,12 +449,39 @@ func main() {
 			if err != nil {
 				log.Fatal("E! " + err.Error())
 			}
+
+			// The sub_Filters are populated when the filter flags are set after the subcommand config
+			// e.g. telegraf config --section-filter inputs
+			subSectionFilters := deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubSectionFilters)+":", ":"))
+			subInputFilters := deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubInputFilters)+":", ":"))
+			subOutputFilters := deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubOutputFilters)+":", ":"))
+			subAggregatorFilters := deleteEmpty(strings.Split(":"+strings.TrimSpace(*fsubAggregatorFilters)+":", ":"))
+			subProcessorFilters := deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubProcessorFilters)+":", ":"))
+
+			// Overwrite the global filters if the subfilters are defined, this allows for backwards compatibility
+			// Now you can still filter the sample config like so: telegraf --section-filter inputs config
+			if len(subSectionFilters) > 0 {
+				sectionFilters = subSectionFilters
+			}
+			if len(subInputFilters) > 0 {
+				inputFilters = subInputFilters
+			}
+			if len(subOutputFilters) > 0 {
+				outputFilters = subOutputFilters
+			}
+			if len(subAggregatorFilters) > 0 {
+				aggregatorFilters = subAggregatorFilters
+			}
+			if len(subProcessorFilters) > 0 {
+				processorFilters = subProcessorFilters
+			}
+
 			config.PrintSampleConfig(
-				deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubSectionFilters)+":", ":")),
-				deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubInputFilters)+":", ":")),
-				deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubOutputFilters)+":", ":")),
-				deleteEmpty(strings.Split(":"+strings.TrimSpace(*fsubAggregatorFilters)+":", ":")),
-				deleteEmpty(strings.Split(":"+strings.TrimSpace(*fSubProcessorFilters)+":", ":")),
+				sectionFilters,
+				inputFilters,
+				outputFilters,
+				aggregatorFilters,
+				processorFilters,
 			)
 			return
 		}