Build aarch64 in chroot on ubuntu-24.04-arm

Author: bastimeyer

.github/workflows/build.yaml

@@ -78,17 +78,20 @@ jobs:
         path: out/*
 
   build-in-chroot:
-    runs-on: ubuntu-latest
-    # if: false
-
     strategy:
       fail-fast: false
       matrix:
         include:
-        - alpine_arch: x86_64
         - alpine_arch: x86
+          runner: ubuntu-24.04
+        - alpine_arch: x86_64
+          runner: ubuntu-24.04
         - alpine_arch: armhf
+          runner: ubuntu-24.04
         - alpine_arch: aarch64
+          runner: ubuntu-24.04-arm
+
+    runs-on: ${{ matrix.runner }}
 
     steps:
     - name: Checkout
@@ -103,8 +106,10 @@ jobs:
       env:
         ALPINE_ARCH: ${{ matrix.alpine_arch }}
       run: |
-        sudo apt-get update
-        sudo apt-get -y install qemu-user-static
+        if [ "$(uname -m)" != "${{ matrix.alpine_arch }}" ]; then
+          sudo apt-get update
+          sudo apt-get -y install qemu-user-static
+        fi
         scripts/chroot/chroot_build.sh
 
   upload:

scripts/chroot/chroot_build.sh

@@ -70,17 +70,14 @@ sudo cp -p /etc/resolv.conf miniroot/etc/
 # build.sh combines existing scripts shared by all available build environments
 sudo cp -R "$repo_root_dir"/scripts miniroot/scripts
 
-if [ "$ALPINE_ARCH" = "x86" ] || [ "$ALPINE_ARCH" = "x86_64" ]; then
-    echo "Architecture is x86 or x86_64, hence not using qemu-arm-static"
+if [ "$(uname -m)" = "${ALPINE_ARCH}" -o "${ALPINE_ARCH}" = "x86" -a "$(uname -m)" = "x86_64" ]; then
     sudo chroot miniroot /bin/sh -ex /scripts/chroot/build.sh
-elif [ "$ALPINE_ARCH" = "aarch64" ] ; then
-    echo "Architecture is aarch64, hence using qemu-aarch64-static"
+elif [ "${ALPINE_ARCH}" = "aarch64" ] ; then
     sudo cp "$(which qemu-aarch64-static)" miniroot/usr/bin
     sudo chroot miniroot qemu-aarch64-static /bin/sh -ex /scripts/chroot/build.sh
-elif [ "$ALPINE_ARCH" = "armhf" ] ; then
-    echo "Architecture is armhf, hence using qemu-arm-static"
+elif [ "${ALPINE_ARCH}" = "armhf" ] ; then
     sudo cp "$(which qemu-arm-static)" miniroot/usr/bin
-    sudo cp "$repo_root_dir"/scripts/chroot/build.sh miniroot/build.sh && sudo chroot miniroot qemu-arm-static /bin/sh -ex /scripts/chroot/build.sh
+    sudo chroot miniroot qemu-arm-static /bin/sh -ex /scripts/chroot/build.sh
 else
     echo "Edit chroot_build.sh to support this architecture as well, it should be easy"
     exit 1