nixos/telegraf: make sure ping executable is available when trying to ping (#338673)

nixos/modules/services/monitoring/telegraf.nix

@@ -61,7 +61,8 @@ in {
       wantedBy = [ "multi-user.target" ];
       wants = [ "network-online.target" ];
       after = [ "network-online.target" ];
-      path = lib.optional (config.services.telegraf.extraConfig.inputs ? procstat) pkgs.procps;
+      path = lib.optional (config.services.telegraf.extraConfig.inputs ? procstat) pkgs.procps
+             ++ lib.optional (config.services.telegraf.extraConfig.inputs ? ping) pkgs.iputils;
       serviceConfig = {
         EnvironmentFile = config.services.telegraf.environmentFiles;
         ExecStartPre = lib.optional (config.services.telegraf.environmentFiles != [])

nixos/tests/telegraf.nix

@@ -19,6 +19,12 @@ import ./make-test-python.nix ({ pkgs, ...} : {
         timeout = "5s";
         data_format = "influx";
       };
+      inputs.ping = {
+        urls = ["127.0.0.1"];
+        count = 4;
+        interval = "10s";
+        timeout = 1.0;
+      };
       outputs.file.files = ["/tmp/metrics.out"];
       outputs.file.data_format = "influx";
     };
@@ -29,5 +35,6 @@ import ./make-test-python.nix ({ pkgs, ...} : {
 
     machine.wait_for_unit("telegraf.service")
     machine.wait_until_succeeds("grep -q example /tmp/metrics.out")
+    machine.wait_until_succeeds("grep -q ping /tmp/metrics.out")
   '';
 })