Fix i386 builds

Author: TheAssassin

.github/workflows/main.yml

@@ -11,27 +11,25 @@ on:
 jobs:
   appimage:
     strategy:
+      fail-fast: false
       matrix:
-        arch: ['x86_64', 'i386']
+        ARCH: [x86_64, i386]
 
-    name: AppImage ${{ matrix.arch }}
+    name: AppImage ${{ matrix.ARCH }}
     runs-on: ubuntu-20.04
     env:
       ARCH: ${{ matrix.ARCH }}
+      APPIMAGE_EXTRACT_AND_RUN: 1
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
         with:
           submodules: recursive
-      - name: Install dependencies
-        if: ${{ matrix.ARCH == 'i386' }}
-        run: |
-            sudo dpkg --add-architecture i386
-            sudo apt-get update
-            sudo apt-get install -y g++-multilib libc6-dev:i386 libstdc++-5-dev:i386 zlib1g:i386 libfuse2:i386
-      - name: Build AppImage
-        run: bash -ex ci/build-appimage.sh
+      - name: Set up QEMU integration for Docker
+        run: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+      - name: Run build in Docker
+        run: bash -euxo pipefail ci/build-in-docker.sh
       - name: Archive artifacts
-        uses: actions/upload-artifact@v2
+        uses: actions/upload-artifact@v3
         with:
           name: AppImage ${{ matrix.ARCH }}
           path: linuxdeploy-plugin-appimage*.AppImage*

ci/build-appimage.sh

@@ -1,18 +1,17 @@
 #! /bin/bash
 
-set -e
-set -x
+set -euxo pipefail
 
 # use RAM disk if possible
-if [ "$CI" == "" ] && [ -d /dev/shm ]; then
-    TEMP_BASE=/dev/shm
+if [ "${CI:-}" == "" ] && [ -d /docker-ramdisk ]; then
+    TEMP_BASE=/docker-ramdisk
 else
     TEMP_BASE=/tmp
 fi
 
 BUILD_DIR=$(mktemp -d -p "$TEMP_BASE" linuxdeploy-plugin-appimage-build-XXXXXX)
 
-cleanup () {
+cleanup() {
     if [ -d "$BUILD_DIR" ]; then
         rm -rf "$BUILD_DIR"
     fi
@@ -51,7 +50,6 @@ chmod +x linuxdeploy-"$ARCH".AppImage
 wget https://github.com/AppImage/AppImageKit/releases/download/continuous/appimagetool-"$AIK_ARCH".AppImage
 
 chmod +x appimagetool-"$AIK_ARCH".AppImage
-dd if=/dev/zero of=appimagetool-"$AIK_ARCH".AppImage bs=1 count=3 seek=8 conv=notrunc
 
 ./appimagetool-"$AIK_ARCH".AppImage --appimage-extract
 mv squashfs-root/ AppDir/appimagetool-prefix/
@@ -60,7 +58,6 @@ ln -s ../../appimagetool-prefix/AppRun AppDir/usr/bin/appimagetool
 export UPD_INFO="gh-releases-zsync|linuxdeploy|linuxdeploy-plugin-appimage|continuous|linuxdeploy-plugin-appimage-$ARCH.AppImage"
 
 # deploy linuxdeploy-plugin-appimage
-dd if=/dev/zero of=linuxdeploy-x86_64.AppImage bs=1 count=3 seek=8 conv=notrunc
 ./linuxdeploy-"$ARCH".AppImage --appimage-extract-and-run \
      --appdir AppDir -d "$REPO_ROOT"/resources/linuxdeploy-plugin-appimage.desktop \
     -i "$REPO_ROOT"/resources/linuxdeploy-plugin-appimage.svg

ci/build-in-docker.sh

@@ -0,0 +1,66 @@
+#! /bin/bash
+
+set -euxo pipefail
+
+if [[ "${ARCH:-}" == "" ]]; then
+    echo "Usage: env ARCH=... bash $0"
+    exit 1
+fi
+
+case "$ARCH" in
+    x86_64)
+        image_prefix=amd64
+        platform=linux/amd64
+        ;;
+    i386)
+        image_prefix=i386
+        platform=linux/i386
+        ;;
+    armhf)
+        image_prefix=arm32v7
+        platform=linux/arm/v7
+        ;;
+    aarch64)
+        image_prefix=arm64v8
+        platform=linux/arm64/v8
+        ;;
+    *)
+        echo "unknown architecture: $ARCH"
+        exit 2
+        ;;
+esac
+
+image="$image_prefix"/debian:stable
+
+repo_root="$(readlink -f "$(dirname "${BASH_SOURCE[0]}")"/..)"
+
+# run the build with the current user to
+#   a) make sure root is not required for builds
+#   b) allow the build scripts to "mv" the binaries into the /out directory
+uid="$(id -u)"
+
+# make sure Docker image is up to date
+docker pull "$image"
+
+docker run \
+    --platform "$platform" \
+    --rm \
+    -i \
+    -e ARCH \
+    -e GITHUB_ACTIONS \
+    -e GITHUB_RUN_NUMBER \
+    -e OUT_UID="$uid" \
+    -v "$repo_root":/source:ro \
+    -v "$PWD":/out \
+    -w /out \
+    --tmpfs /docker-ramdisk:exec,mode=777 \
+    "$image" \
+    bash -exo pipefail \
+<<\EOF
+
+apt-get update
+apt-get install -y gcc g++ cmake git wget file curl
+
+bash -euxo pipefail ci/build-appimage.sh
+
+EOF