From 77c85b0ecbc1070d7adff31b339bede92e4193fa Mon Sep 17 00:00:00 2001
From: Rob Vermaas <rob.vermaas@gmail.com>
Date: Thu, 4 May 2017 09:40:51 +0000
Subject: [PATCH] dd-agent: Add default config files of dd-agent and auto_conf
 dir to /etc/dd-agent/conf.d by default, and make sure /etc/dd-agent/conf.d is
 used.

Before NixOS 17.03, we were using dd-agent 5.5.X which
used configuration from /etc/dd-agent/conf.d

In NixOS 17.03 the default conf.d location is first used relative,
meaning that $out/agent/conf.d was used without NixOS overrides.

This change implements similar functionality as PR #25288, without
breaking backwards compatibility.
---
 nixos/modules/module-list.nix                            | 2 +-
 .../services/monitoring/dd-agent/dd-agent-defaults.nix   | 8 ++++++++
 .../services/monitoring/{ => dd-agent}/dd-agent.nix      | 7 ++++++-
 .../monitoring/dd-agent/update-dd-agent-defaults         | 9 +++++++++
 pkgs/tools/networking/dd-agent/default.nix               | 3 +++
 5 files changed, 27 insertions(+), 2 deletions(-)
 create mode 100644 nixos/modules/services/monitoring/dd-agent/dd-agent-defaults.nix
 rename nixos/modules/services/monitoring/{ => dd-agent}/dd-agent.nix (96%)
 create mode 100755 nixos/modules/services/monitoring/dd-agent/update-dd-agent-defaults

diff --git a/nixos/modules/module-list.nix b/nixos/modules/module-list.nix
index bf2f936b688e..5ba81f2dd69c 100644
--- a/nixos/modules/module-list.nix
+++ b/nixos/modules/module-list.nix
@@ -314,7 +314,7 @@
   ./services/monitoring/cadvisor.nix
   ./services/monitoring/collectd.nix
   ./services/monitoring/das_watchdog.nix
-  ./services/monitoring/dd-agent.nix
+  ./services/monitoring/dd-agent/dd-agent.nix
   ./services/monitoring/grafana.nix
   ./services/monitoring/graphite.nix
   ./services/monitoring/hdaps.nix
diff --git a/nixos/modules/services/monitoring/dd-agent/dd-agent-defaults.nix b/nixos/modules/services/monitoring/dd-agent/dd-agent-defaults.nix
new file mode 100644
index 000000000000..045128197421
--- /dev/null
+++ b/nixos/modules/services/monitoring/dd-agent/dd-agent-defaults.nix
@@ -0,0 +1,8 @@
+# Generated using update-dd-agent-default, please re-run after updating dd-agent. DO NOT EDIT MANUALLY.
+[
+  "auto_conf"
+  "agent_metrics.yaml.default"
+  "disk.yaml.default"
+  "network.yaml.default"
+  "ntp.yaml.default"
+]
diff --git a/nixos/modules/services/monitoring/dd-agent.nix b/nixos/modules/services/monitoring/dd-agent/dd-agent.nix
similarity index 96%
rename from nixos/modules/services/monitoring/dd-agent.nix
rename to nixos/modules/services/monitoring/dd-agent/dd-agent.nix
index a98b0f2f0f85..2fb1b9020bff 100644
--- a/nixos/modules/services/monitoring/dd-agent.nix
+++ b/nixos/modules/services/monitoring/dd-agent/dd-agent.nix
@@ -75,7 +75,12 @@ let
   jmxConfig = pkgs.writeText "jmx.yaml" cfg.jmxConfig;
   
   etcfiles =
-    [ { source = ddConf;
+    let
+      defaultConfd = import ./dd-agent-defaults.nix;
+    in (map (f: { source = "${pkgs.dd-agent}/agent/conf.d-system/${f}";
+                  target = "dd-agent/conf.d/${f}";
+                }) defaultConfd) ++ [
+      { source = ddConf;
         target = "dd-agent/datadog.conf";
       }
       { source = diskConfig;
diff --git a/nixos/modules/services/monitoring/dd-agent/update-dd-agent-defaults b/nixos/modules/services/monitoring/dd-agent/update-dd-agent-defaults
new file mode 100755
index 000000000000..76724173171a
--- /dev/null
+++ b/nixos/modules/services/monitoring/dd-agent/update-dd-agent-defaults
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+dd=$(nix-build --no-out-link -A dd-agent ../../../..)
+echo '# Generated using update-dd-agent-default, please re-run after updating dd-agent. DO NOT EDIT MANUALLY.' > dd-agent-defaults.nix
+echo '[' >> dd-agent-defaults.nix
+echo '  "auto_conf"' >> dd-agent-defaults.nix
+for f in $(find $dd/agent/conf.d-system -maxdepth 1 -type f | grep -v '\.example' | sort); do
+  echo "  \"$(basename $f)\"" >> dd-agent-defaults.nix
+done
+echo ']' >> dd-agent-defaults.nix
diff --git a/pkgs/tools/networking/dd-agent/default.nix b/pkgs/tools/networking/dd-agent/default.nix
index 10b7b47b3f4c..e9a70b17130c 100644
--- a/pkgs/tools/networking/dd-agent/default.nix
+++ b/pkgs/tools/networking/dd-agent/default.nix
@@ -64,6 +64,9 @@ in stdenv.mkDerivation rec {
     ln -s $out/agent/dogstatsd.py $out/bin/dogstatsd
     ln -s $out/agent/ddagent.py $out/bin/dd-forwarder
 
+    # Move out default conf.d so that /etc/dd-agent/conf.d is used
+    mv $out/agent/conf.d $out/agent/conf.d-system
+
     cat > $out/bin/dd-jmxfetch <<EOF
     #!/usr/bin/env bash
     exec ${python}/bin/python $out/agent/jmxfetch.py $@