From b3f68289df646a82c9b87d866244510ff1d2866a Mon Sep 17 00:00:00 2001
From: Louis Blin <45168934+lbpdt@users.noreply.github.com>
Date: Thu, 25 Mar 2021 16:38:37 +0000
Subject: dockerTools.streamLayeredImage: resolve duplicate env vars

For images running on Kubernetes, there is no guarantee on how duplicate
environment variables in the image config will be handled. This seems
to be different from Docker, where the last environment variable value
is consistently selected.

The current code for `streamLayeredImage` was exploiting that assumption
to easily propagate environment variables from the base image, leaving
duplicates unchecked. It should rather resolve these duplicates to
ensure consistent behavior on Docker and Kubernetes.
---
 pkgs/build-support/docker/stream_layered_image.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'pkgs/build-support')

diff --git a/pkgs/build-support/docker/stream_layered_image.py b/pkgs/build-support/docker/stream_layered_image.py
index 3e5781ba1c806..d7c63eb43a78f 100644
--- a/pkgs/build-support/docker/stream_layered_image.py
+++ b/pkgs/build-support/docker/stream_layered_image.py
@@ -202,7 +202,9 @@ def overlay_base_config(from_image, final_config):
     # Preserve environment from base image
     final_env = base_config.get("Env", []) + final_config.get("Env", [])
     if final_env:
-        final_config["Env"] = final_env
+        # Resolve duplicates (last one wins) and format back as list
+        resolved_env = {entry.split("=", 1)[0]: entry for entry in final_env}
+        final_config["Env"] = list(resolved_env.values())
     return final_config
 
 
-- 
cgit 1.4.1