www/nginx: support for ip_hash option

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

@@ -10,6 +10,12 @@
     <style>selectpicker</style>
     <type>select_multiple</type>
   </field>
+  <field>
+    <id>upstream.load_balancing_algorithm</id>
+    <label>Load Balancing Algorithm</label>
+    <style>selectpicker</style>
+    <type>dropdown</type>
+  </field>
   <field>
     <id>upstream.proxy_protocol</id>
     <label>PROXY Protocol</label>

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

@@ -82,6 +82,13 @@
         <Required>Y</Required>
         <multiple>Y</multiple>
       </serverentries>
+      <load_balancing_algorithm type="OptionField">
+        <OptionValues>
+          <ip_hash>IP Hash</ip_hash>
+        </OptionValues>
+        <BlankDesc>Weighted Round Robin</BlankDesc>
+        <Required>N</Required>
+      </load_balancing_algorithm>
       <proxy_protocol type="BooleanField">
         <default>0</default>
         <Required>Y</Required>

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

@@ -7,6 +7,11 @@
 {% endfor %}
 {% for upstream_uuid, upstream in upstreamlist.items() %}
 upstream upstream{{ upstream_uuid.replace('-','') }} {
+{%   if upstream.load_balancing_algorithm is defined and upstream.load_balancing_algorithm != '' %}
+{%     if upstream.load_balancing_algorithm == 'ip_hash' %}
+ip_hash;
+{%     endif %}
+{%   endif %}
 {%   for upstream_serveruuid in upstream.serverentries.split(',') %}
 {%     set upstream_server = helpers.getUUID(upstream_serveruuid) %}
 server {% if ':' in upstream_server.server %}[{% endif %}{{ upstream_server.server }}{% if ':' in upstream_server.server %}]{% endif