chore: make bpftool installable in alpine linux (#117)

3rdparty/bpftool.sh

@@ -1,8 +1,25 @@
 #!/bin/bash -e
 
+if [ ! -f /etc/os-release ]; then
+    echo "Unknown OS"
+    exit 1
+fi
+
+# shellcheck source=/dev/null
+# See SC1091
+. /etc/os-release
+
+if [ "$ID" == "alpine" ]; then
+    sudo apk add build-base elfutils-dev zlib-dev libcap-dev binutils-dev pkgconf libelf
+elif [ "$ID" == "ubuntu" ]; then
+    sudo apt-get -y install build-essential libelf-dev libz-dev libcap-dev binutils-dev pkg-config libelf1
+else
+    echo "Unsupported OS"
+    exit 1
+fi
+
 git submodule update --init --recursive 3rdparty/bpftool
 cd ./3rdparty/bpftool
-sudo apt-get -y install build-essential libelf-dev libz-dev libcap-dev binutils-dev pkg-config libelf1
 make -C src clean
 CC=clang make -C src all
 sudo cp ./src/bpftool /usr/sbin/bpftool