From 3733a14b87decb930849d1feced32f0076edba32 Mon Sep 17 00:00:00 2001
From: Julien Pivotto <291750+roidelapluie@users.noreply.github.com>
Date: Tue, 20 Jan 2026 12:21:01 +0100
Subject: [PATCH] Fix ARG scoping in Dockerfile.distroless

ARG declarations before FROM are only available within the FROM
instruction and go out of scope afterward. Re-declare ARCH and OS
after FROM so they're available for the COPY instructions.

This fixes the build failure where ${OS}-${ARCH} resolved to empty
strings, causing "not found" errors for .build/-/prometheus.

Signed-off-by: Julien Pivotto <291750+roidelapluie@users.noreply.github.com>
---
 Dockerfile.distroless | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Dockerfile.distroless b/Dockerfile.distroless
index c338851bd4..0ee184a91c 100644
--- a/Dockerfile.distroless
+++ b/Dockerfile.distroless
@@ -1,11 +1,12 @@
-ARG ARCH="amd64"
-ARG OS="linux"
 ARG DISTROLESS_ARCH="amd64"
 
 # Use DISTROLESS_ARCH for base image selection (handles armv7->arm mapping).
 FROM gcr.io/distroless/static-debian13:nonroot-${DISTROLESS_ARCH}
 # Base image sets USER to 65532:65532 (nonroot user).
 
+ARG ARCH="amd64"
+ARG OS="linux"
+
 LABEL org.opencontainers.image.authors="The Prometheus Authors"
 LABEL org.opencontainers.image.vendor="Prometheus"
 LABEL org.opencontainers.image.title="Prometheus"