nixos/caddy: don't set ExecReload if enableReload is disabled

Otherwise, setting services.caddy.enableReload to false fails in a very bad fashion:

The reload command still gets executed, but fails:

```
Apr 26 21:23:01 n1-rk1 systemd[1]: Reloading Caddy...
Apr 26 21:23:01 n1-rk1 caddy[70793]: {"level":"info","ts":1714166581.733018,"msg":"using provided configuration","config_file":"/etc/caddy/caddy_config","config_adapter":"caddyfile"}
Apr 26 21:23:01 n1-rk1 caddy[70793]: {"level":"warn","ts":1714166581.7353032,"msg":"Caddyfile input is not formatted; run 'caddy fmt --overwrite' to fix inconsistencies","adapter":"caddyfile","file":"/etc/caddy/caddy_config","line":3}
Apr 26 21:23:01 n1-rk1 caddy[70793]: Error: sending configuration to instance: performing request: Post "http://localhost:2019/load": dial tcp [::1]:2019: connect: connection refused
Apr 26 21:23:01 n1-rk1 systemd[1]: caddy.service: Control process exited, code=exited, status=1/FAILURE
Apr 26 21:23:01 n1-rk1 systemd[1]: Reload failed for Caddy.
```

… and the server is not restarted either, as a ExecReload= command is
specified.

Fix this, by only setting ExecReload if the reload exists.

The first empty string is still necessary to reset the old option.

1 files changed, 1 insertions, 1 deletions

diff --git a/nixos/modules/services/web-servers/caddy/default.nix b/nixos/modules/services/web-servers/caddy/default.nix
index 1cd1448c7d567..064a0c71b586b 100644
--- a/nixos/modules/services/web-servers/caddy/default.nix
+++ b/nixos/modules/services/web-servers/caddy/default.nix
@@ -365,7 +365,7 @@ in
         # If the empty string is assigned to this option, the list of commands to start is reset, prior assignments of this option will have no effect.
         ExecStart = [ "" ''${cfg.package}/bin/caddy run ${runOptions} ${optionalString cfg.resume "--resume"}'' ];
         # Validating the configuration before applying it ensures we’ll get a proper error that will be reported when switching to the configuration
-        ExecReload = [ "" ''${cfg.package}/bin/caddy reload ${runOptions} --force'' ];
+        ExecReload = [ "" ] ++ lib.optional cfg.enableReload "${lib.getExe cfg.package} reload ${runOptions} --force";
         User = cfg.user;
         Group = cfg.group;
         ReadWritePaths = [ cfg.dataDir ];