www/nginx: Add basic support for forced caching (#4481)

Author: ltning

www/nginx/src/opnsense/mvc/app/controllers/OPNsense/Nginx/forms/location.xml

@@ -96,6 +96,13 @@
     <advanced>true</advanced>
     <help>Enter how often the resource must be hit before adding it to the cache.</help>
   </field>
+  <field>
+    <id>location.cache_valid</id>
+    <label>Cache: Force caching time</label>
+    <type>text</type>
+    <advanced>true</advanced>
+    <help>Force caching of 200, 301 and 302 responses according to the request methods enabled for caching. Given in minutes; leave empty to rely on request/response headers from client and upstream.</help>
+  </field>
   <field>
     <id>location.cache_background_update</id>
     <label>Cache: Background Update</label>

www/nginx/src/opnsense/mvc/app/models/OPNsense/Nginx/Nginx.xml

@@ -349,6 +349,9 @@
         <Required>Y</Required>
         <default>1</default>
       </cache_min_uses>
+      <cache_valid type="IntegerField">
+        <Required>N</Required>
+      </cache_valid>
       <cache_background_update type="BooleanField">
         <Required>Y</Required>
         <default>0</default>

www/nginx/src/opnsense/service/templates/OPNsense/Nginx/location.conf

@@ -142,6 +142,9 @@ location {{ location.matchtype }} {{ location.urlpattern }} {
     proxy_cache {{ location.cache_path.replace('-', '') }};
 {%   if location.cache_use_stale is defined and location.cache_use_stale != '' %}
     proxy_cache_use_stale  {{ location.cache_use_stale.replace(',', ' ') }};
+{%   endif %}
+{%   if location.cache_valid is defined and location.cache_valid != '' %}
+    proxy_cache_valid  {{ location.cache_valid }}m;
 {%   endif %}
     proxy_cache_min_uses {{ location.cache_min_uses|default('1') }};
     proxy_cache_background_update {% if location.cache_background_update is defined and location.cache_background_update == '1' %}on{% else %}off{% endif %};