From ba3c0221a2b21d94255a0eb1dc785d36ca47b298 Mon Sep 17 00:00:00 2001
From: gsayer <9694317+gsayer@users.noreply.github.com>
Date: Mon, 29 Jun 2026 17:03:15 +0200
Subject: [PATCH] ci(release): publish multi-arch image
 (linux/amd64,linux/arm64)

The release workflow built for the runner arch only (amd64) and the
Dockerfile was not arch-aware. Align it with the Backend/WebApp pattern:
pin the build stage to $BUILDPLATFORM and branch restore/publish on
$TARGETARCH (--runtime linux-arm64|linux-x64 --self-contained false).
The final stage has no RUN, so buildx cross-builds the arm64 image from
the amd64 runner with no QEMU. Add platforms to the build-push step.

Verified locally: buildx --platform linux/amd64,linux/arm64 produces a
multi-arch manifest list with no emulation.
---
 .github/workflows/release.yml |  1 +
 Dockerfile                    | 22 ++++++++++++++++------
 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 2e11d80..f6b2de8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -205,6 +205,7 @@ jobs:
         uses: docker/build-push-action@v6
         with:
           context: .
+          platforms: linux/amd64,linux/arm64
           push: true
           build-args: |
             GITHUB_TOKEN=${{ secrets.PAT_DISPATCH }}
diff --git a/Dockerfile b/Dockerfile
index fdbc2d0..995efe0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,7 @@
-# Build stage
-FROM mcr.microsoft.com/dotnet/sdk:10.0 AS build
+# Build stage with multi-platform support
+FROM --platform=$BUILDPLATFORM mcr.microsoft.com/dotnet/sdk:10.0 AS build
+ARG TARGETARCH
+ARG BUILDPLATFORM
 ARG GITHUB_TOKEN
 ARG NUGET_SOURCE=github
 WORKDIR /src
@@ -21,13 +23,21 @@ RUN if [ "${NUGET_SOURCE}" = "github" ]; then \
         --store-password-in-clear-text; \
     fi
 
-# Restore dependencies (cached layer)
-RUN dotnet restore "PayrollEngine.PayrollConsole.sln"
+# Restore with architecture-specific runtime
+RUN if [ "$TARGETARCH" = "arm64" ]; then \
+      dotnet restore "PayrollEngine.PayrollConsole.sln" --runtime linux-arm64; \
+    else \
+      dotnet restore "PayrollEngine.PayrollConsole.sln" --runtime linux-x64; \
+    fi
 
-# Copy remaining source files and publish
+# Copy remaining source files and publish with architecture-specific runtime
 COPY . .
 WORKDIR "/src/PayrollConsole"
-RUN dotnet publish "PayrollEngine.PayrollConsole.csproj" -c Release -o /app/publish --no-restore
+RUN if [ "$TARGETARCH" = "arm64" ]; then \
+      dotnet publish "PayrollEngine.PayrollConsole.csproj" -c Release -o /app/publish --runtime linux-arm64 --self-contained false; \
+    else \
+      dotnet publish "PayrollEngine.PayrollConsole.csproj" -c Release -o /app/publish --runtime linux-x64 --self-contained false; \
+    fi
 
 # Runtime stage
 FROM mcr.microsoft.com/dotnet/aspnet:10.0