Fix release Android cross-builds with NDK toolchain

.github/workflows/go.yml

@@ -44,6 +44,21 @@ jobs:
         with:
           go-version: 1.25
 
+      - name: Set up Android SDK
+        uses: android-actions/setup-android@v3
+
+      - name: Install Android NDK
+        run: |
+          set -euo pipefail
+          # sdkmanager exits after consuming enough input; `yes` then gets SIGPIPE.
+          # Temporarily disable pipefail so the pipeline status reflects sdkmanager.
+          set +o pipefail
+          yes | sdkmanager --licenses >/dev/null
+          set -o pipefail
+          sdkmanager --install "ndk;27.1.12297006"
+          echo "ANDROID_NDK_HOME=${ANDROID_SDK_ROOT}/ndk/27.1.12297006" >> "${GITHUB_ENV}"
+          echo "ANDROID_API_LEVEL=21" >> "${GITHUB_ENV}"
+
       - name: Build release artifacts
         run: ./pack.sh
 

pack.sh

@@ -4,6 +4,77 @@ NAME="pingtunnel"
 
 export GO111MODULE=on
 
+resolve_ndk_host_tag() {
+  local host_os
+  local host_arch
+  host_os=$(uname -s)
+  host_arch=$(uname -m)
+
+  case "${host_os}/${host_arch}" in
+    Linux/x86_64)
+      echo "linux-x86_64"
+      ;;
+    Darwin/x86_64)
+      echo "darwin-x86_64"
+      ;;
+    Darwin/arm64)
+      echo "darwin-arm64"
+      ;;
+    *)
+      return 1
+      ;;
+  esac
+}
+
+prepare_android_toolchain() {
+  local arch="$1"
+  local ndk_home
+  local host_tag
+  local api_level
+  local target
+
+  ndk_home="${ANDROID_NDK_HOME:-${ANDROID_NDK_ROOT:-}}"
+  if [ -z "$ndk_home" ]; then
+    echo "ANDROID_NDK_HOME or ANDROID_NDK_ROOT must be set for Android builds"
+    return 1
+  fi
+
+  host_tag=$(resolve_ndk_host_tag) || {
+    echo "Unsupported host for Android NDK toolchain: $(uname -s)/$(uname -m)"
+    return 1
+  }
+
+  api_level="${ANDROID_API_LEVEL:-21}"
+  case "$arch" in
+    386)
+      target="i686-linux-android"
+      ;;
+    amd64)
+      target="x86_64-linux-android"
+      ;;
+    arm)
+      target="armv7a-linux-androideabi"
+      ;;
+    arm64)
+      target="aarch64-linux-android"
+      ;;
+    *)
+      echo "Unsupported Android arch: $arch"
+      return 1
+      ;;
+  esac
+
+  ANDROID_CC="$ndk_home/toolchains/llvm/prebuilt/$host_tag/bin/${target}${api_level}-clang"
+  ANDROID_CXX="$ndk_home/toolchains/llvm/prebuilt/$host_tag/bin/${target}${api_level}-clang++"
+
+  if [ ! -x "$ANDROID_CC" ] || [ ! -x "$ANDROID_CXX" ]; then
+    echo "Android toolchain not found for $arch at $ndk_home"
+    return 1
+  fi
+
+  return 0
+}
+
 #go tool dist list
 build_list=$(go tool dist list)
 
@@ -19,23 +90,28 @@ for line in $build_list; do
   os=$(echo "$line" | awk -F"/" '{print $1}')
   arch=$(echo "$line" | awk -F"/" '{print $2}')
   echo "os="$os" arch="$arch" start build"
-  if [ $os == "ios" ]; then
+  if [ "$os" == "ios" ]; then
     continue
   fi
-  if [ $arch == "wasm" ]; then
+  if [ "$arch" == "wasm" ]; then
     continue
   fi
-  if [ $os = "android" ]; then
-    #CGO_ENABLED=1 GOOS=$os GOARCH=$arch go build -ldflags="-s -w"
-    continue
+
+  if [ "$os" == "android" ]; then
+    prepare_android_toolchain "$arch" || {
+      echo "os="$os" arch="$arch" toolchain setup fail"
+      exit 1
+    }
+    CGO_ENABLED=1 GOOS=$os GOARCH=$arch CC="$ANDROID_CC" CXX="$ANDROID_CXX" go build -ldflags="-s -w"
   else
     CGO_ENABLED=0 GOOS=$os GOARCH=$arch go build -ldflags="-s -w"
-  fi  
+  fi
+
   if [ $? -ne 0 ]; then
     echo "os="$os" arch="$arch" build fail"
     exit 1
   fi
-  if [ $os = "windows" ]; then
+  if [ "$os" = "windows" ]; then
     mv cmd.exe ${NAME}.exe
     zip ${NAME}_"${os}"_"${arch}"".zip" ${NAME}.exe
     if [ $? -ne 0 ]; then