From a4afd525cb9ab90b71977142489ac154a701b7d0 Mon Sep 17 00:00:00 2001
From: Kirill Elagin <kirelagin@gmail.com>
Date: Sun, 20 Sep 2020 17:38:46 -0400
Subject: [PATCH] prometheus: Unbreak IPv6 listenAddress

The format of the listenAddress option was recently changed to separate
the address and the port parts. There is now a legacy check that
tells users to update to the new format. This legacy check produces
a false positive on IPv6 addresses, since they contain colons.

Fix the regex to make it not match colons within IPv6 addresses.
---
 nixos/modules/services/monitoring/prometheus/default.nix | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/monitoring/prometheus/default.nix b/nixos/modules/services/monitoring/prometheus/default.nix
index d7e06484b69289..bfd4951ef48adc 100644
--- a/nixos/modules/services/monitoring/prometheus/default.nix
+++ b/nixos/modules/services/monitoring/prometheus/default.nix
@@ -629,7 +629,9 @@ in {
   config = mkIf cfg.enable {
     assertions = [
       ( let
-          legacy = builtins.match "(.*):(.*)" cfg.listenAddress;
+          # Match something with dots (an IPv4 address) or something ending in
+          # a square bracket (an IPv6 addresses) followed by a port number.
+          legacy = builtins.match "(.*\\..*|.*]):([[:digit:]]+)" cfg.listenAddress;
         in {
           assertion = legacy == null;
           message = ''