{
  description = "Grafana Loki";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  # Nixpkgs / NixOS version to use.

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        golangci-lint-overlay = final: prev: {
          golangci-lint = prev.callPackage
            "${prev.path}/pkgs/development/tools/golangci-lint"
            {
              buildGoModule = args:
                prev.buildGoModule (args // rec {
                  version = "1.45.2";

                  src = prev.fetchFromGitHub rec {
                    owner = "golangci";
                    repo = "golangci-lint";
                    rev = "v${version}";
                    sha256 =
                      "sha256-Mr45nJbpyzxo0ZPwx22JW2WrjyjI9FPpl+gZ7NIc6WQ=";
                  };

                  vendorSha256 =
                    "sha256-pcbKg1ePN8pObS9EzP3QYjtaty27L9sroKUs/qEPtJo=";

                  ldflags = [
                    "-s"
                    "-w"
                    "-X main.version=${version}"
                    "-X main.commit=v${version}"
                    "-X main.date=19700101-00:00:00"
                  ];
                });
            };
        };

        helm-docs-overlay = final: prev: {
          helm-docs = prev.callPackage
            "${prev.path}/pkgs/applications/networking/cluster/helm-docs"
            {
              buildGoModule = args:
                prev.buildGoModule (args // rec {
                  version = "1.8.1";

                  src = prev.fetchFromGitHub {
                    owner = "norwoodj";
                    repo = "helm-docs";
                    rev = "v${version}";
                    sha256 = "sha256-OpS/CYBb2Ll6ktvEhqkw/bWMSrFa4duidK3Glu8EnPw=";
                  };

                  vendorSha256 = "sha256-FpmeOQ8nV+sEVu2+nY9o9aFbCpwSShQUFOmyzwEQ9Pw=";

                  ldflags = [
                    "-w"
                    "-s"
                    "-X main.version=v${version}"
                  ];
                });
            };
        };

        nix = import ./nix { inherit self nixpkgs system; };

        pkgs = import nixpkgs {
          inherit system;
          overlays = [
            golangci-lint-overlay
            helm-docs-overlay
            nix.overlay
          ];
          config = { allowUnfree = true; };
        };
      in
      with pkgs; {
        # The default package for 'nix build'. This makes sense if the
        # flake provides only one package or there is a clear "main"
        # package.
        defaultPackage = loki;

        packages = { inherit loki; };

        apps = {
          lint = {
            type = "app";
            program = "${
                (writeShellScriptBin "lint.sh" ''
                  ${nixpkgs-fmt}/bin/nixpkgs-fmt --check ${self}/flake.nix ${self}/nix/*.nix
                  ${statix}/bin/statix check ${self}
                '')
              }/bin/lint.sh";
          };

          loki = {
            type = "app";
            program = with pkgs; "${loki.overrideAttrs(old: rec { doCheck = false; })}/bin/loki";
          };
          promtail = {
            type = "app";
            program = with pkgs; "${loki.overrideAttrs(old: rec { doCheck = false; })}/bin/promtail";
          };
          logcli = {
            type = "app";
            program = with pkgs; "${loki.overrideAttrs(old: rec { doCheck = false; })}/bin/logcli";
          };
          loki-canary = {
            type = "app";
            program = with pkgs; "${loki.overrideAttrs(old: rec { doCheck = false; })}/bin/loki-canary";
          };
        };

        devShell = mkShell {
          nativeBuildInputs = [
            gcc
            go
            systemd
            yamllint
            nixpkgs-fmt
            statix
            nettools

            golangci-lint
            helm-docs
            faillint
            chart-testing
            chart-releaser
          ];

          shellHook = ''
            pushd $(git rev-parse --show-toplevel) > /dev/null || exit 1
            ./nix/generate-build-vars.sh
            popd > /dev/null || exit 1
          '';
        };
      });
}