From 6ad76e4b330e2ee14ce515a880580bc66398b993 Mon Sep 17 00:00:00 2001
From: "Dustin C. Hatch" <dustin@hatch.name>
Date: Wed, 3 Dec 2025 22:01:58 -0600
Subject: [PATCH] r/fluent-bit: Support drop-in configuration files

Fluent Bit supports including configuration fragments from other files
using its `includes` option.  Adding a glob pattern to the default
configuration will allow other roles to supply additional configuration
by creating files in the `/etc/fluent-bit/include` directory.  This
makes composition of configuration significantly easier.

Unfortunately, `fluent-bit` has a quirk in that there must exist at
least one file matching the glob pattern, or it will fail to start.  To
work around this, we must supply an empty fragment.
---
 roles/fluent-bit/defaults/main.yml |  2 ++
 roles/fluent-bit/tasks/main.yml    | 23 +++++++++++++++++++++++
 2 files changed, 25 insertions(+)

diff --git a/roles/fluent-bit/defaults/main.yml b/roles/fluent-bit/defaults/main.yml
index b50d6f4..93ef4d7 100644
--- a/roles/fluent-bit/defaults/main.yml
+++ b/roles/fluent-bit/defaults/main.yml
@@ -1,4 +1,6 @@
 fluent_bit_config:
+  includes:
+  - /etc/fluent-bit/include/*.yml
   service: '{{ fluent_bit_config_service }}'
   parsers: '{{ fluent_bit_parsers }}'
   multiline_parsers: '{{ fluent_bit_multiline_parsers }}'
diff --git a/roles/fluent-bit/tasks/main.yml b/roles/fluent-bit/tasks/main.yml
index 55c25ee..39005de 100644
--- a/roles/fluent-bit/tasks/main.yml
+++ b/roles/fluent-bit/tasks/main.yml
@@ -5,6 +5,29 @@
   tags:
   - install
 
+- name: ensure fluent-bit config include directory exists
+  file:
+    path: /etc/fluent-bit/include
+    owner: root
+    group: root
+    mode: u=rwx,go=
+    state: directory
+  tags:
+  - config
+# fluent-bit will fail to start if a glob pattern listed in `includes` does not
+# match any files.  To allow roles to drop additiona configuration files in the
+# include directory without modifying the main configuration file, we need to
+# have an empty file in the include directory all the time.
+- name: ensure fluent-bit empty include file exists
+  copy:
+    dest: /etc/fluent-bit/include/_.yml
+    content: ''
+    owner: root
+    group: root
+    mode: u=rwx,go=
+  tags:
+  - config
+
 - name: ensure fluent-bit is configured
   copy:
     dest: /etc/fluent-bit/fluent-bit.yml