nixpkgs/nixos/tests/prometheus/remote-write.nix

{
  name = "prometheus-remote-write";

  nodes = {
    receiver =
      { config, pkgs, ... }:
      {
        environment.systemPackages = [ pkgs.jq ];

        networking.firewall.allowedTCPPorts = [ config.services.prometheus.port ];

        services.prometheus = {
          enable = true;
          globalConfig.scrape_interval = "2s";

          extraFlags = [ "--web.enable-remote-write-receiver" ];
        };
      };

    prometheus =
      { config, pkgs, ... }:
      {
        environment.systemPackages = [ pkgs.jq ];

        networking.firewall.allowedTCPPorts = [ config.services.prometheus.port ];

        services.prometheus = {
          enable = true;
          globalConfig.scrape_interval = "2s";

          remoteWrite = [ { url = "http://receiver:9090/api/v1/write"; } ];

          scrapeConfigs = [
            {
              job_name = "node";
              static_configs = [
                { targets = [ "node:${toString config.services.prometheus.exporters.node.port}" ]; }
              ];
            }
          ];
        };
      };

    node =
      { config, pkgs, ... }:
      {
        services.prometheus.exporters.node = {
          enable = true;
          openFirewall = true;
        };
      };
  };

  testScript = ''
    node.wait_for_unit("prometheus-node-exporter")
    node.wait_for_open_port(9100)

    for machine in prometheus, receiver:
      machine.wait_for_unit("prometheus")
      machine.wait_for_open_port(9090)

    # Verify both servers got the same data from the exporter
    for machine in prometheus, receiver:
      machine.wait_until_succeeds(
        "curl -sf 'http://127.0.0.1:9090/api/v1/query?query=node_exporter_build_info\{instance=\"node:9100\"\}' | "
        + "jq '.data.result[0].value[1]' | grep '\"1\"'"
      )
  '';
}