nixos/prometheus: add webExternalUrl option

Similar to the prometheus.alertmanager.webExternalUrl option, but for
Prometheus itself.

1 files changed, 11 insertions, 0 deletions

diff --git a/nixos/modules/services/monitoring/prometheus/default.nix b/nixos/modules/services/monitoring/prometheus/default.nix
index 5dda763bd56b7..e2ee995cea801 100644
--- a/nixos/modules/services/monitoring/prometheus/default.nix
+++ b/nixos/modules/services/monitoring/prometheus/default.nix
@@ -39,6 +39,7 @@ let
     "-alertmanager.notification-queue-capacity=${toString cfg.alertmanagerNotificationQueueCapacity}"
     "-alertmanager.timeout=${toString cfg.alertmanagerTimeout}s"
     (optionalString (cfg.alertmanagerURL != []) "-alertmanager.url=${concatStringsSep "," cfg.alertmanagerURL}")
+    (optionalString (cfg.webExternalUrl != null) "-web.external-url=${cfg.webExternalUrl}")
   ];
 
   promTypes.globalConfig = types.submodule {
@@ -467,6 +468,16 @@ in {
           Alert manager HTTP API timeout (in seconds).
         '';
       };
+
+      webExternalUrl = mkOption {
+        type = types.nullOr types.str;
+        default = null;
+        example = "https://example.com/";
+        description = ''
+          The URL under which Prometheus is externally reachable (for example,
+          if Prometheus is served via a reverse proxy).
+        '';
+      };
     };
   };