Challenge solutions

Challenge 1 – Descriptors

In this challenge, we need to use the --descriptor_set_out flag to generate binary out of our schema. Let us define a simple schema (name.proto):

syntax = "proto3";
message Name {
  string name = 1;
}

To generate a FileDescriptorSet out of it, we need to run the following command:

$ protoc --descriptor_set_out=name.desc name.proto

This will create a name.desc file that we can then analyze.

Now, the second step is to use --decode to set the internals of the FileDescriptorSet. To do that, assuming that you have the descriptor.proto file in /usr/local/include/google/protobuf, you can run the following:

$ cat name.desc | protoc -I/usr/local/include/google/protobuf --decode=google.protobuf.FileDescriptorSet /usr/local/include/google/protobuf/descriptor.proto

This should output something like this:

file {
  name: "name.proto"
  message_type {
   &...