From 4ead9419c5dca21ea40dd13c69a92838f683788d Mon Sep 17 00:00:00 2001
From: Giacomo Marciani <mgiacomo@amazon.com>
Date: Tue, 23 Dec 2025 16:55:20 -0500
Subject: [PATCH] [Logging] Add ISO 8601 timestamps with milliseconds precision
 to Chef client logs.

---
 CHANGELOG.md                                                 | 1 +
 cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml | 1 +
 2 files changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 27cd7ba5be..20f7e6d7b1 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ CHANGELOG
 - Add validator that warns against the downsides of disabling in-place updates on compute and login nodes through DevSettings.
 - Upgrade jmespath to ~=1.0 (from ~=0.10).
 - Upgrade tabulate to <=0.9.0 (from <=0.8.10).
+- Add ISO 8601 timestamp with milliseconds precision to chef-client.log.
 
 **BUG FIXES**
 - Add validation to block updates that change tag order. Blocking such change prevents update failures.
diff --git a/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml b/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
index c476a5e304..4a15914834 100644
--- a/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
+++ b/cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml
@@ -234,6 +234,7 @@ phases:
           - path: /etc/chef/client.rb
             content: |
               cookbook_path ['/etc/chef/cookbooks']
+              require '/etc/chef/cookbooks/aws-parallelcluster-shared/libraries/log_formatter'
             overwrite: true
           - path: /etc/parallelcluster/image_dna.json
             content: |