From 7a5c968dc5c977e2fc6814b01564d215fb578386 Mon Sep 17 00:00:00 2001
From: Monviech <79600909+Monviech@users.noreply.github.com>
Date: Sat, 13 Apr 2024 14:58:42 +0200
Subject: [PATCH] www/caddy: Add simple load balancing (#3911)

* Add: Simple Load Balancing support of Upstreams with the random policy, by allowing multiple Upstream Domains in Handlers.

* Add passive health fail duration test. It enables unhealthy upstreams to be sorted when simple load balancing is enabled.

* Update pkg-descr
---
 www/caddy/pkg-descr                                 |  3 +++
 .../OPNsense/Caddy/forms/dialogHandle.xml           | 13 +++++++++++--
 .../mvc/app/models/OPNsense/Caddy/Caddy.xml         |  7 +++++++
 .../mvc/app/views/OPNsense/Caddy/reverse_proxy.volt |  1 +
 .../service/templates/OPNsense/Caddy/Caddyfile      |  9 ++++++++-
 5 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/www/caddy/pkg-descr b/www/caddy/pkg-descr
index 93d02a539..452ecabe8 100644
--- a/www/caddy/pkg-descr
+++ b/www/caddy/pkg-descr
@@ -19,6 +19,7 @@ Main features of this plugin:
 * Syslog-ng integration and HTTP Access Log
 * NTLM Transport
 * Header manipulation with header_up and header_down
+* Simple load balancing with passive health check
 
 DOC: https://docs.opnsense.org/manual/how-tos/caddy.html
 
@@ -34,6 +35,8 @@ Plugin Changelog
 * Add: Header functionality added. Multiple header manipulations can be set per handler.
 * Cleanup: Update searchBase() in ReverseProxyController.php for easier maintainability.
 * Fix: Move selectpicker empty option to model in general.volt, using BlankDesc. This fixes the option IPv4+IPv6 not appearing in Dynamic DNS. 
+* Add: Simple Load Balancing support with the default random policy, by allowing to add multiple Upstream Domains in Handlers.
+* Add: Passive Health check for load balancing (Upstream Fail Duration) in Handlers.
 
 1.5.3
 
diff --git a/www/caddy/src/opnsense/mvc/app/controllers/OPNsense/Caddy/forms/dialogHandle.xml b/www/caddy/src/opnsense/mvc/app/controllers/OPNsense/Caddy/forms/dialogHandle.xml
index 51bf04077..4a6d5ee50 100644
--- a/www/caddy/src/opnsense/mvc/app/controllers/OPNsense/Caddy/forms/dialogHandle.xml
+++ b/www/caddy/src/opnsense/mvc/app/controllers/OPNsense/Caddy/forms/dialogHandle.xml
@@ -56,9 +56,11 @@
     <field>
         <id>handle.ToDomain</id>
         <label>Upstream Domain</label>
-        <type>text</type>
+        <type>select_multiple</type>
+        <style>tokenize</style>
+        <allownew>true</allownew>
         <hint>192.168.1.1</hint>
-        <help><![CDATA[Enter the internal domain name or IP address of the upstream destination for this handler.]]></help>
+        <help><![CDATA[Enter the internal domain name or IP address of the upstream destination for this handler. If multiple upstream destinations are chosen, they will be load balanced with the default random policy.]]></help>
     </field>
     <field>
         <id>handle.ToPort</id>
@@ -74,6 +76,13 @@
         <help><![CDATA[Enter a path prefix like '/guacamole' that should be prepended to the upstream request because the application demands it.]]></help>
         <advanced>true</advanced>
     </field>
+    <field>
+        <id>handle.PassiveHealthFailDuration</id>
+        <label>Upstream Fail Duration</label>
+        <type>text</type>
+        <help><![CDATA[Enables a passive health check when multiple upstream destinations have been defined for load balancing. "fail_duration" is a duration value that defines how long to remember a failed request. A duration of 1 or more seconds enables passive health checking; the default is empty (off). A reasonable starting point might be 30s to balance error rates with responsiveness when bringing an unhealthy upstream back online.]]></help>
+        <advanced>true</advanced>
+    </field>
     <field>
         <type>header</type>
         <label>Trust</label>
diff --git a/www/caddy/src/opnsense/mvc/app/models/OPNsense/Caddy/Caddy.xml b/www/caddy/src/opnsense/mvc/app/models/OPNsense/Caddy/Caddy.xml
index d967254ef..acfc075d9 100644
--- a/www/caddy/src/opnsense/mvc/app/models/OPNsense/Caddy/Caddy.xml
+++ b/www/caddy/src/opnsense/mvc/app/models/OPNsense/Caddy/Caddy.xml
@@ -256,6 +256,8 @@
                     <Required>Y</Required>
                     <ValidationMessage>Please enter a valid 'to' domain or IP address.</ValidationMessage>
                     <IpAllowed>Y</IpAllowed>
+                    <FieldSeparator>,</FieldSeparator>
+                    <AsList>Y</AsList>
                 </ToDomain>
                 <ToPort type="PortField">
                     <ValidationMessage>Please enter a valid 'to' port number.</ValidationMessage>
@@ -266,6 +268,11 @@
                     <Mask>/^(\/.*)?$/u</Mask>
                     <ValidationMessage>Please enter a valid 'Backend Path' that starts with '/'.</ValidationMessage>
                 </ToPath>
+                <PassiveHealthFailDuration type="IntegerField">
+                    <MinimumValue>1</MinimumValue>
+                    <MaximumValue>100</MaximumValue>
+                    <ValidationMessage>Please enter a value between 1 to 100.</ValidationMessage>
+                </PassiveHealthFailDuration>
                 <HttpTls type="BooleanField"/>
                 <HttpNtlm type="BooleanField"/>
                 <HttpTlsInsecureSkipVerify type="BooleanField"/>
diff --git a/www/caddy/src/opnsense/mvc/app/views/OPNsense/Caddy/reverse_proxy.volt b/www/caddy/src/opnsense/mvc/app/views/OPNsense/Caddy/reverse_proxy.volt
index 7f397b615..5d9ebc406 100644
--- a/www/caddy/src/opnsense/mvc/app/views/OPNsense/Caddy/reverse_proxy.volt
+++ b/www/caddy/src/opnsense/mvc/app/views/OPNsense/Caddy/reverse_proxy.volt
@@ -247,6 +247,7 @@
                             <th data-column-id="ToDomain" data-type="string">Upstream Domain</th>
                             <th data-column-id="ToPort" data-type="string">Upstream Port</th>
                             <th data-column-id="ToPath" data-type="string" data-visible="false">Upstream Path</th>
+                            <th data-column-id="PassiveHealthFailDuration" data-type="string" data-visible="false">Fail Duration</th>
                             <th data-column-id="HttpTls" data-type="boolean" data-formatter="boolean" data-visible="false">TLS</th>
                             <th data-column-id="HttpTlsTrustedCaCerts" data-type="string" data-visible="false">TLS CA</th>
                             <th data-column-id="HttpTlsServerName" data-type="string" data-visible="false">TLS Server Name</th>
diff --git a/www/caddy/src/opnsense/service/templates/OPNsense/Caddy/Caddyfile b/www/caddy/src/opnsense/service/templates/OPNsense/Caddy/Caddyfile
index 6a4272fb2..178c3ea78 100644
--- a/www/caddy/src/opnsense/service/templates/OPNsense/Caddy/Caddyfile
+++ b/www/caddy/src/opnsense/service/templates/OPNsense/Caddy/Caddyfile
@@ -500,14 +500,21 @@
 #       - HttpTlsInsecureSkipVerify (boolean, optional): If true, the server's SSL certificate is not verified.
 #       - HttpTlsTrustedCaCerts (string, optional): The config extracted name of a CA certificate.
 #       - HttpTlsServerName (string, optional): Specifies the server name for the TLS handshake.
+#       - PassiveHealthFailDuration (integer, optional): Enables passive health checks when set > 0.
 #}
 {% macro reverse_proxy_configuration(handle) %}
     {{ handle.HandleType }} {{ handle.HandlePath|default("") }} {
         {% if handle.ToPath|default("") != "" %}
         rewrite * {{ handle.ToPath }}{uri}
         {% endif %}
-        reverse_proxy {{ handle.ToDomain }}{% if handle.ToPort %}:{{ handle.ToPort }}{% endif %} {
+        reverse_proxy {% for domain in handle.ToDomain.split(',') %}
+            {# For each domain/IP, append the port if it's specified, followed by a space #}
+            {{- domain -}}{% if handle.ToPort %}:{{ handle.ToPort }}{% endif %}{% if not loop.last %} {% endif %}
+        {% endfor %}{
             {{ header_manipulation(handle) }}
+            {% if handle.PassiveHealthFailDuration|default("") %}
+            fail_duration {{ handle.PassiveHealthFailDuration }}s
+            {% endif %}
             {% if handle.HttpTls|default("0") == "1" or handle.HttpTlsInsecureSkipVerify|default("0") == "1" %}
                 {% if handle.HttpNtlm|default("0") == "1" %}
                 transport http_ntlm {