oci: user-data: Try to decode base64 content

Terraform only supports sending any shell scripts encoded in base64
which is however not required by Oracle. Therefore we have to test if
the script is encoded or not.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>

src/initscripts/helper/oci-setup

@@ -34,6 +34,24 @@ get() {
 	wget -qO - "http://169.254.169.254/opc/v1/${file}"
 }
 
+try_base64_decode() {
+	local input="${1}"
+
+	local tmp="$(mktemp)"
+
+	# Try to decode this and return output if successful
+	if base64 -d <<< "${input}" > "${tmp}" 2>/dev/null; then
+		echo "$(<${tmp})"
+
+	# Otherwise just return the input
+	else
+		echo "${input}"
+	fi
+
+	# Cleanup
+	unlink "${tmp}"
+}
+
 to_address() {
 	local n="${1}"
 
@@ -134,6 +152,9 @@ import_oci_configuration() {
 		# Download a startup script
 		local script="$(get instance/metadata/user_data)"
 
+		# Try to decode this
+		script="$(try_base64_decode "${script}")"
+
 		# Execute the script
 		if [ "${script:0:2}" = "#!" ]; then
 			echo "${script}" > /tmp/user-data.script