From d96a3994cc9b032778a3d3f3a29f660332ef91bc Mon Sep 17 00:00:00 2001
From: Guillaume Girol <symphorien+git@xlumurb.eu>
Date: Wed, 22 Dec 2021 12:00:00 +0000
Subject: nixos/collectd: validate config file syntax at build time

---
 nixos/modules/services/monitoring/collectd.nix | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

(limited to 'nixos/modules/services/monitoring/collectd.nix')

diff --git a/nixos/modules/services/monitoring/collectd.nix b/nixos/modules/services/monitoring/collectd.nix
index 660d108587de..8d81737a3ef0 100644
--- a/nixos/modules/services/monitoring/collectd.nix
+++ b/nixos/modules/services/monitoring/collectd.nix
@@ -5,7 +5,7 @@ with lib;
 let
   cfg = config.services.collectd;
 
-  conf = pkgs.writeText "collectd.conf" ''
+  unvalidated_conf = pkgs.writeText "collectd-unvalidated.conf" ''
     BaseDir "${cfg.dataDir}"
     AutoLoadPlugin ${boolToString cfg.autoLoadPlugin}
     Hostname "${config.networking.hostName}"
@@ -30,6 +30,15 @@ let
     ${cfg.extraConfig}
   '';
 
+  conf = if cfg.validateConfig then
+    pkgs.runCommand "collectd.conf" {} ''
+      echo testing ${unvalidated_conf}
+      # collectd -t fails if BaseDir does not exist.
+      sed '1s/^BaseDir.*$/BaseDir "."/' ${unvalidated_conf} > collectd.conf
+      ${package}/bin/collectd -t -C collectd.conf
+      cp ${unvalidated_conf} $out
+    '' else unvalidated_conf;
+
   package =
     if cfg.buildMinimalPackage
     then minimalPackage
@@ -43,6 +52,16 @@ in {
   options.services.collectd = with types; {
     enable = mkEnableOption "collectd agent";
 
+    validateConfig = mkOption {
+      default = true;
+      description = ''
+        Validate the syntax of collectd configuration file at build time.
+        Disable this if you use the Include directive on files unavailable in
+        the build sandbox, or when cross-compiling.
+      '';
+      type = types.bool;
+    };
+
     package = mkOption {
       default = pkgs.collectd;
       defaultText = literalExpression "pkgs.collectd";
-- 
cgit 1.4.1