T6246: adds haproxy http-check configuration documentation

vyos · Apr 17, 2024 · d70f20f · d70f20f
1 parent a2666e8
commit d70f20f
Showing 1 changed file with 52 additions and 0 deletions.
diff --git a/docs/configuration/loadbalancing/reverse-proxy.rst b/docs/configuration/loadbalancing/reverse-proxy.rst
@@ -145,6 +145,32 @@ Backend
   Send a Proxy Protocol version 2 header (binary format)
 
 
+HTTP health check
+^^^^^^^^^^^^^^^^^
+For web application providing information about their state HTTP health checks can be used
+to determine their availability.
+
+.. cfgcmd:: set load-balancing reverse-proxy backend <name> http-check
+
+Enables HTTP health checks using OPTION HTTP requests against '/' and
+expecting a successful response in the 200-399 range.
+
+.. cfgcmd:: set load-balancing reverse-proxy backend <name> http-check method <method>
+
+Sets the HTTP method to be used, can be either: option, get, post, put
+
+.. cfgcmd:: set load-balancing reverse-proxy backend <name> http-check uri <path>
+
+Sets the endpoint to be used for health checks
+
+.. cfgcmd:: set load-balancing reverse-proxy backend master http-check expect <condition>
+
+Sets the expected result for considering it healthy.
+Some possible examples are:
+   * ``status 200`` Expecting a 200 response code
+   * ``status 200-399`` Expecting a non-failure response code
+   * ``string success`` Expecting the string `success` in the response body
+
 
 Gloabal
 -------
@@ -287,3 +313,29 @@ connection limit of 4000 and a minimum TLS version of 1.3.
     set load-balancing reverse-proxy global-parameters max-connections '4000'
     set load-balancing reverse-proxy global-parameters tls-version-min '1.3'
 
+
+Balancing with HTTP health checks
+---------------------------------
+
+This configuration enables HTTP health checks on backend servers.
+
+.. code-block:: none
+
+    set load-balancing reverse-proxy service my-tcp-api backend 'bk-01'
+    set load-balancing reverse-proxy service my-tcp-api mode 'tcp'
+    set load-balancing reverse-proxy service my-tcp-api port '8888'
+
+    set load-balancing reverse-proxy backend bk-01 balance 'round-robin'
+    set load-balancing reverse-proxy backend bk-01 mode 'tcp'
+
+    set load-balancing reverse-proxy backend bk-01 http-check method 'get'
+    set load-balancing reverse-proxy backend bk-01 http-check uri '/health'
+    set load-balancing reverse-proxy backend bk-01 http-check expect 'status 200'
+
+    set load-balancing reverse-proxy backend bk-01 server srv01 address '192.0.2.11'
+    set load-balancing reverse-proxy backend bk-01 server srv01 port '8881'
+    set load-balancing reverse-proxy backend bk-01 server srv01 check
+    set load-balancing reverse-proxy backend bk-01 server srv02 address '192.0.2.12'
+    set load-balancing reverse-proxy backend bk-01 server srv02 port '8882'
+    set load-balancing reverse-proxy backend bk-01 server srv02 check
+