From 438ff2307cf59cd96b2cd044dc925ddfb935301a Mon Sep 17 00:00:00 2001
From: Pierre Riteau <pierre@stackhpc.com>
Date: Mon, 29 Aug 2022 12:01:18 +0200
Subject: [PATCH] Support configuring HAProxy services as active/passive

Instead of specifying a custom member list for each service that should
be configured as active/passive, a new `active_passive` parameter can be
set to true. This only works if `custom_member_list` is not used.

Change-Id: I3758bc2377c25a277a29f02ebc20c946c7499093
---
 .../templates/haproxy_single_service_split.cfg.j2         | 8 +++++---
 .../notes/haproxy-active-passive-523139557659d6e5.yaml    | 5 +++++
 2 files changed, 10 insertions(+), 3 deletions(-)
 create mode 100644 releasenotes/notes/haproxy-active-passive-523139557659d6e5.yaml

diff --git a/ansible/roles/haproxy-config/templates/haproxy_single_service_split.cfg.j2 b/ansible/roles/haproxy-config/templates/haproxy_single_service_split.cfg.j2
index 7dfbcc012e..6e5b71bf72 100644
--- a/ansible/roles/haproxy-config/templates/haproxy_single_service_split.cfg.j2
+++ b/ansible/roles/haproxy-config/templates/haproxy_single_service_split.cfg.j2
@@ -52,7 +52,7 @@ frontend {{ service_name }}_front
 {% endmacro %}
 
 {%- macro backend_macro(service_name, listen_port, service_mode, host_group,
-                        custom_member_list, backend_http_extra,
+                        active_passive, custom_member_list, backend_http_extra,
                         backend_tcp_extra, auth_user, auth_pass, tls_backend) %}
 backend {{ service_name }}_back
     {% if service_mode == 'redirect' %}
@@ -98,7 +98,7 @@ backend {{ service_name }}_back
     {% if hostvars[host][service_weight] is defined and hostvars[host][service_weight] | int != 0 and hostvars[host][service_weight] | int <= 256 %}
         {% set backend_weight_info = 'weight %s'|format(hostvars[host][service_weight]) %}
     {% endif %}
-    server {{ host_name }} {{ host_ip }}:{{ listen_port }} {{ haproxy_health_check_final }} {{ backend_tls_info }} {{ backend_weight_info }}
+    server {{ host_name }} {{ host_ip }}:{{ listen_port }} {{ haproxy_health_check_final }}{% if active_passive and not loop.first %} backup{% endif %} {{ backend_tls_info }} {{ backend_weight_info }}
         {% endfor %}
     {% endif %}
 {% endmacro %}
@@ -107,6 +107,8 @@ backend {{ service_name }}_back
 {%- for haproxy_name, haproxy_service in haproxy.items() %}
     {# External defaults to false #}
     {% set external = haproxy_service.external|default(false)|bool %}
+    {# Active/passive defaults to false #}
+    {% set active_passive = haproxy_service.active_passive|default(false)|bool %}
     {# Skip anything that is external when the external vip is not enabled #}
     {% if haproxy_service.enabled|bool and (not external or haproxy_enable_external_vip|bool)%}
         {# Here we define variables and their defaults #}
@@ -140,7 +142,7 @@ backend {{ service_name }}_back
         {% endif %}
         {# Redirect (to https) is a special case, as it does not include a backend #}
         {% if with_backend and mode != 'redirect' %}
-{{ backend_macro(haproxy_name, listen_port, mode, host_group,
+{{ backend_macro(haproxy_name, listen_port, mode, host_group, active_passive,
                  custom_member_list, backend_http_extra, backend_tcp_extra,
                  auth_user, auth_pass, tls_backend) }}
         {% endif %}
diff --git a/releasenotes/notes/haproxy-active-passive-523139557659d6e5.yaml b/releasenotes/notes/haproxy-active-passive-523139557659d6e5.yaml
new file mode 100644
index 0000000000..f500605c9b
--- /dev/null
+++ b/releasenotes/notes/haproxy-active-passive-523139557659d6e5.yaml
@@ -0,0 +1,5 @@
+---
+features:
+  - |
+    Supports configuration of arbitrary HAProxy services in active/passive
+    mode.