nixos/netdata: copy apps_groups.conf instead of symlink (NixOS#356313)

nixos/modules/services/monitoring/netdata.nix

@@ -24,7 +24,7 @@ let
     mkdir $out
     ${lib.concatStringsSep "\n" (lib.mapAttrsToList (path: file: ''
         mkdir -p "$out/$(dirname ${path})"
-        ln -s "${file}" "$out/${path}"
+        ${if path == "apps_groups.conf" then "cp" else "ln -s"} "${file}" "$out/${path}"
       '') cfg.configDir)}
   '';
 

nixos/tests/netdata.nix

@@ -14,6 +14,10 @@ import ./make-test-python.nix ({ pkgs, ...} : {
           services.netdata = {
             enable = true;
             python.recommendedPythonPackages = true;
+
+            configDir."apps_groups.conf" = pkgs.writeText "apps_groups.conf" ''
+              netdata_test: netdata
+            '';
           };
         };
     };
@@ -33,12 +37,20 @@ import ./make-test-python.nix ({ pkgs, ...} : {
     # check if netdata can read disk ops for root owned processes.
     # if > 0, successful. verifies both netdata working and
     # apps.plugin has elevated capabilities.
-    url = "http://localhost:19999/api/v1/data\?chart=user.root_disk_physical_io"
+    url = "http://localhost:19999/api/v1/data?chart=user.root_disk_physical_io"
     filter = '[.data[range(10)][2]] | add | . < 0'
     cmd = f"curl -s {url} | jq -e '{filter}'"
     netdata.wait_until_succeeds(cmd)
 
     # check if the control socket is available
     netdata.succeed("sudo netdatacli ping")
+
+    # check that custom groups in apps_groups.conf are used.
+    # if > 0, successful. verifies that user-specified apps_group.conf
+    # is used.
+    url = "http://localhost:19999/api/v1/data?chart=app.netdata_test_cpu_utilization"
+    filter = '[.data[range(10)][2]] | add | . > 0'
+    cmd = f"curl -s {url} | jq -e '{filter}'"
+    netdata.wait_until_succeeds(cmd, timeout=30)
   '';
 })