Update configure.sh

configure.sh

@@ -61,9 +61,21 @@ else
 	exit 2
 fi
 
-echo "cargo install bpf-linker into /usr/local/bin"
-cargo install --force bpf-linker
-mv -f ~/.cargo/bin/bpf-linker /usr/local/bin
+# ask for user to install bpf-linker
+if [ "${YES}" == "-y" ]; then
+	echo "cargo install bpf-linker into /usr/local/bin"
+	cargo install --force bpf-linker
+	mv -f ~/.cargo/bin/bpf-linker /usr/local/bin
+else
+	read -r -p "Install bpf-linker in /usr/local/bin? (mandatory for build) [y/N] " response
+	case "$response" in
+		[yY][eE][sS]|[yY]|[oO]) 
+			echo "cargo install bpf-linker into /usr/local/bin"
+			cargo install --force bpf-linker
+			mv -f ~/.cargo/bin/bpf-linker /usr/local/bin
+			;;
+	esac
+fi
 
 export $(grep -h '^ID' /etc/*-release)