Add test of Go module versions

Make sure that the Go versions in all `go.mod` files are in sync.

Signed-off-by: SuperQ <superq@gmail.com>

Makefile

@@ -93,9 +93,9 @@ endif
 # If we only want to only test go code we have to change the test target
 # which is called by all.
 ifeq ($(GO_ONLY),1)
-test: common-test
+test: common-test check-go-mod-version
 else
-test: common-test ui-build-module ui-test ui-lint
+test: common-test ui-build-module ui-test ui-lint check-go-mod-version
 endif
 
 .PHONY: npm_licenses
@@ -138,3 +138,8 @@ bench_tsdb: $(PROMU)
 cli-documentation:
 	$(GO) run ./cmd/prometheus/ --write-documentation > docs/command-line/prometheus.md
 	$(GO) run ./cmd/promtool/ write-documentation > docs/command-line/promtool.md
+
+.PHONY: check-go-mod-version
+check-go-mod-version:
+	@echo ">> checking go.mod version matching"
+	@./scripts/check-go-mod-version.sh

documentation/examples/remote_storage/go.mod

@@ -1,6 +1,6 @@
 module github.com/prometheus/prometheus/documentation/examples/remote_storage
 
-go 1.18
+go 1.20
 
 require (
 	github.com/alecthomas/kingpin/v2 v2.3.2

scripts/check-go-mod-version.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env bash
+
+readarray -t mod_files < <(find . -type f -name go.mod)
+
+echo "Checking files ${mod_files[@]}"
+
+matches=$(awk '$1 == "go" {print $2}' "${mod_files[@]}" | sort -u | wc -l)
+
+if [[ "${matches}" -ne 1 ]]; then
+  echo 'Not all go.mod files have matching go versions'
+  exit 1
+fi