From 11f45c83621f8169f1c0dba8462196903697b0f1 Mon Sep 17 00:00:00 2001
From: Leon Vack <dev@lgcl.de>
Date: Mon, 8 Apr 2024 11:00:14 +0200
Subject: [PATCH] nixos/alertmanager: add additional docs about envsubst

Environment variables in the alertmanager config are substituted using
envsubst. It is therefore necessary to escape $ as $$ in the config, if it
should be preserved.
---
 .../modules/services/monitoring/prometheus/alertmanager.nix | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/nixos/modules/services/monitoring/prometheus/alertmanager.nix b/nixos/modules/services/monitoring/prometheus/alertmanager.nix
index bb426d8b7beb..a96cc8d96be8 100644
--- a/nixos/modules/services/monitoring/prometheus/alertmanager.nix
+++ b/nixos/modules/services/monitoring/prometheus/alertmanager.nix
@@ -51,6 +51,9 @@ in {
         default = null;
         description = lib.mdDoc ''
           Alertmanager configuration as nix attribute set.
+
+          The contents of the resulting config file are processed using envsubst.
+          `$` needs to be escaped as `$$` to be preserved.
         '';
       };
 
@@ -62,6 +65,9 @@ in {
           defines the text that is written to alertmanager.yml. If null, the
           contents of alertmanager.yml is generated from the structured config
           options.
+
+          The contents of the resulting config file are processed using envsubst.
+          `$` needs to be escaped as `$$` to be preserved.
         '';
       };