From 795bed94a4b507b5ebbee87f266f98abed368403 Mon Sep 17 00:00:00 2001
From: kruskal <99559985+kruskall@users.noreply.github.com>
Date: Fri, 12 Aug 2022 21:36:27 +0200
Subject: [PATCH] fix: make zip task compatible with other systems

The zip task was relying on 'touch -d @seconds' to set the timestamp of
output files to allow reproducible builds.
'touch -d @seconds' is not POSIX compliant and the standard only supports
a subset of formats:

https://man7.org/linux/man-pages/man1/touch.1p.html

The standard way of doing it would be to use one of those format or just use
'touch -t TIME'.
Since SOURCE_DATE_EPOCH is providing seconds since epoch and we don't have a
standard way to convert them to a standard format used by touch, we rely on
'date' and use a fallback mechanism to try two different syntax:

- Busybox and GNU coreutils date
- BSD date
---
 apm-lambda-extension/Makefile | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/apm-lambda-extension/Makefile b/apm-lambda-extension/Makefile
index e6308e82..5623aebf 100644
--- a/apm-lambda-extension/Makefile
+++ b/apm-lambda-extension/Makefile
@@ -8,6 +8,11 @@ AGENT_VERSION = $(shell echo $${BRANCH_NAME} | cut -f 2 -d 'v')
 # Add support for SOURCE_DATE_EPOCH and reproducble buils
 # See https://reproducible-builds.org/specs/source-date-epoch/
 SOURCE_DATE_EPOCH ?= $(shell git log -1 --pretty=%ct)
+DATE_FMT = +%Y%m%d%H%M.%S
+# Fallback mechanism to support other systems:
+# 1. 'date -d': Busybox and GNU coreutils.
+# 2. 'date -r': BSD date. It does not support '-d'.
+BUILD_DATE = $(shell date -u -d "@${SOURCE_DATE_EPOCH}" "${DATE_FMT}" 2>/dev/null || date -u -r "${SOURCE_DATE_EPOCH}" "${DATE_FMT}")
 
 ifndef GOARCH
 	GOARCH=amd64
@@ -62,7 +67,7 @@ endif
 zip:
 	cd bin \
 	&& rm -f extension.zip \
-	&& find extensions NOTICE.txt dependencies.asciidoc | xargs touch -d @$(SOURCE_DATE_EPOCH) \
+	&& find extensions NOTICE.txt dependencies.asciidoc | xargs touch -t ${BUILD_DATE} \
 	&& zip -X -r extension.zip extensions NOTICE.txt dependencies.asciidoc \
 	&& cp extension.zip ${GOARCH}.zip
 test: