chore: update-beats goal to bump the go version (#5778)

.ci/scripts/update-beats.sh

@@ -9,7 +9,9 @@ make update-beats
 COMMIT_MESSAGE="Update to elastic/beats@$(go list -m -f {{.Version}} github.com/elastic/beats/... | cut -d- -f3)"
 
 git checkout -b "update-beats-$(date "+%Y%m%d%H%M%S")"
-git add go.mod go.sum NOTICE.txt
+git add go.mod go.sum NOTICE.txt .go-version docs/version.asciidoc
+find . -maxdepth 2 -name Dockerfile -exec git add {} \;
+
 git diff --staged --quiet || git commit -m "$COMMIT_MESSAGE"
 git --no-pager log -1
 

.gitignore

@@ -35,4 +35,6 @@ html_docs
 /docker-compose.override.yml
 /config.mk
 /systemtest/logs
-docker-compose.yml.bck
+docker-compose.yml.bck
+Dockerfile.bck
+version.asciidoc.bck

Makefile

@@ -191,8 +191,9 @@ update-beats: update-beats-module update
 .PHONY: update-beats-module
 update-beats-module:
 	$(GO) get -d -u $(BEATS_MODULE)@$(BEATS_VERSION) && $(GO) mod tidy
-	diff -u .go-version $$($(GO) list -m -f {{.Dir}} $(BEATS_MODULE))/.go-version \
-		|| { code=$$?; echo ".go-version out of sync with Beats"; exit $$code; }
+	cp -f $$($(GO) list -m -f {{.Dir}} $(BEATS_MODULE))/.go-version .go-version
+	find . -maxdepth 2 -name Dockerfile -exec sed -i'.bck' -E -e "s#(FROM golang):[0-9]+\.[0-9]+\.[0-9]+#\1:$$(cat .go-version)#g" {} \;
+	sed -i'.bck' -E -e "s#(:go-version): [0-9]+\.[0-9]+\.[0-9]+#\1: $$(cat .go-version)#g" docs/version.asciidoc
 
 ##############################################################################
 # Kibana synchronisation.

README.md

@@ -16,7 +16,7 @@ To get started with APM, see our [Quick start guide](https://www.elastic.co/guid
 
 ### Requirements
 
-* [Golang](https://golang.org/dl/) 1.16.6
+* [Golang](https://golang.org/dl/) 1.16.x
 
 ### Install