nixos/prometheus-snmp-exporter: update log options

The allowed values have changed in bd3319d28c43580c74839a10dca5d348cc3e0b29.

0.15:
      --log.level="info"        Only log messages with the given severity or above. Valid levels: [debug, info, warn, error, fatal]
      --log.format="logger:stderr"
                                Set the log target and format. Example: "logger:syslog?appname=bob&local=7" or "logger:stdout?json=true"

0.17:
      --log.level=info          Only log messages with the given severity or above. One of: [debug, info, warn, error]
      --log.format=logfmt       Output format of log messages. One of: [logfmt, json]

1 files changed, 4 insertions, 4 deletions

diff --git a/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix b/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix
index 606c9162059a..ddde3c104810 100644
--- a/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix
+++ b/nixos/modules/services/monitoring/prometheus/exporters/snmp.nix
@@ -36,15 +36,15 @@ in
     };
 
     logFormat = mkOption {
-      type = types.str;
-      default = "logger:stderr";
+      type = types.enum ["logfmt" "json"];
+      default = "logfmt";
       description = ''
-        Set the log target and format.
+        Output format of log messages.
       '';
     };
 
     logLevel = mkOption {
-      type = types.enum ["debug" "info" "warn" "error" "fatal"];
+      type = types.enum ["debug" "info" "warn" "error"];
       default = "info";
       description = ''
         Only log messages with the given severity or above.