grafana: serve files locally and allow caching for static files

Author: sni

packages/grafana/skel/etc/apache/conf.d/grafana.conf

@@ -7,6 +7,17 @@
 
 RewriteEngine On
 
+# server public folder directly, no need to pass through grafana and reverse proxy.
+RewriteCond %{REQUEST_URI} ^/${OMD_SITE}/grafana/public/(.*)$
+RewriteCond "${OMD_ROOT}/share/grafana/public/$1" "-f"
+RewriteRule "^/${OMD_SITE}/grafana/public/(.*)" "${OMD_ROOT}/share/grafana/public/$1" [L]
+
+# enable caching for static files
+<LocationMatch /${OMD_SITE}/grafana/public/(build|img)/>
+    ExpiresActive On
+    ExpiresDefault "access plus 3 days"
+</LocationMatch>
+
 <Location /${OMD_SITE}/grafana>
     ProxyPass http://127.0.0.1:###CONFIG_GRAFANA_TCP_PORT###/${OMD_SITE}/grafana retry=0 disablereuse=On
     ProxyPassReverse http://127.0.0.1:###CONFIG_GRAFANA_TCP_PORT###/${OMD_SITE}/grafana