add the checkmk agent and config

checkmk-agent/default.nix

@@ -0,0 +1,26 @@
+{ stdenv, lib, makeWrapper }:
+
+stdenv.mkDerivation rec {
+  name = "checkmk-agent";
+  src = ./agent.tar.gz;
+  phases = [ "unpackPhase" "installPhase" "fixupPhase" "wrapPhase" ];
+  buildInputs = [ ];
+  nativeBuildInputs = [ makeWrapper ];
+
+  installPhase = ''
+    mkdir -p $out/bin
+    install -m 0755 check_mk_agent.linux $out/bin/check_mk_agent
+    substitute sshwrapper $out/bin/check_mk_agent.sshwrapper \
+      --replace SUDOCOMMAND "$out/bin/check_mk_agent"
+    chmod 0755 $out/bin/check_mk_agent.sshwrapper
+    '';
+  wrapPhase = ''
+    wrapProgram $out/bin/check_mk_agent --suffix PATH : /run/current-system/sw/bin
+    '';
+
+  meta = with lib; {
+    description = "checkmk-agent";
+    platforms   = platforms.all;
+  };
+}
+

checkmk-agent/files/sshwrapper

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+set -euo pipefail
+# The agent does not need stdin
+exec </dev/null
+exec sudo --non-interactive -- SUDOCOMMAND