github: add buildci and its helper script

Signed-off-by: Gunwant Jain <mail@wantguns.dev>

.github/buildci.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+set -xe
+
+# Setup cross compiling for arm64
+setup_cross_compiling() {
+    __ARCH=$1
+
+    if [ "$__ARCH" == "arm64" ]; then
+        sudo apt update
+        sudo apt install -y gcc-aarch64-linux-gnu
+        rustup target add aarch64-unknown-linux-gnu
+    fi
+}
+
+# Building for the given architecture
+build_for_arch() {
+    __ARCH=$1
+    __SHA=$2
+
+    # Statically compile
+    case "$__ARCH" in \
+        arm64) export __TARGET='aarch64-unknown-linux-gnu' ;;
+        amd64) export __TARGET='x86_64-unknown-linux-gnu' ;;
+    esac
+
+    # Build and install
+    cargo install --target $__TARGET --path .
+
+    # Export them artifacts
+    mkdir -p artifacts
+    cp -av /home/runner/.cargo/bin/bin "artifacts/bin-$__SHA-$__TARGET"
+}

.github/workflows/buildci.yml

@@ -0,0 +1,41 @@
+name: Build CI
+
+on: 
+  push:
+    branches:
+      - "*"
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  build:
+    strategy:
+      matrix: 
+        arch: [amd64, arm64]
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout project
+        uses: actions/checkout@v2
+      
+      - name: Setup cross compiling
+        run: |
+          source ./.github/buildci.sh
+          setup_cross_compiling ${{ matrix.arch }}
+      
+      - name: Format
+        run: cargo fmt -- --check
+
+      - name: Clippy
+        run: cargo clippy -- -Dwarnings
+
+      - name: Build 
+        run: |
+          source ./.github/buildci.sh
+          build_for_arch ${{ matrix.arch }} ${GITHUB_SHA::7}
+
+      - name: Export artifacts
+        uses: actions/upload-artifact@v2
+        with:
+          name: build-artifacts
+          path: artifacts