Add monitoring mixing for Grafana (#28285)

Co-authored-by: Tom Wilkie <tom.wilkie@gmail.com>

scripts/lib.star

@@ -224,6 +224,7 @@ def lint_backend_step(edition):
             'revive -formatter stylish -config scripts/go/configs/revive.toml ./pkg/...',
             './scripts/revive-strict',
             './scripts/tidy-check.sh',
+            './scripts/mixin-check.sh,
         ],
     }
 

scripts/mixin-check.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+set -eo pipefail
+
+cd grafana-mixin
+go install github.com/monitoring-mixins/mixtool/cmd/mixtool
+go install github.com/google/go-jsonnet/cmd/jsonnetfmt
+make lint build