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.

(cherry picked from commit 77c85b0ecbc1070d7adff31b339bede92e4193fa)

1 files changed, 9 insertions, 0 deletions

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 00000000000..76724173171
--- /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