nixpkgs/nixos/tests/fluentd.nix

import ./make-test-python.nix (
  { pkgs, lib, ... }:
  {
    name = "fluentd";

    nodes.machine =
      { pkgs, ... }:
      {
        services.fluentd = {
          enable = true;
          config = ''
            <source>
              @type http
              port 9880
            </source>

            <match **>
              type copy
              <store>
                @type file
                format json
                path /tmp/fluentd
                symlink_path /tmp/current-log
              </store>
              <store>
                @type stdout
              </store>
            </match>
          '';
        };
      };

    testScript =
      let
        testMessage = "an example log message";

        payload = pkgs.writeText "test-message.json" (
          builtins.toJSON {
            inherit testMessage;
          }
        );
      in
      ''
        machine.start()
        machine.wait_for_unit("fluentd.service")
        machine.wait_for_open_port(9880)

        machine.succeed(
            "curl -fsSL -X POST -H 'Content-type: application/json' -d @${payload} http://localhost:9880/test.tag"
        )

        # blocking flush
        machine.succeed("systemctl stop fluentd")

        machine.succeed("grep '${testMessage}' /tmp/current-log")
      '';
  }
)