Thrift for Zephyr

Build Status

What is Thrift?

Thrift is an IDL specification, RPC framework, and code generator. It works across all major operating systems, supports over 27 programming languages, 7 protocols, and 6 low-level transports. Thrift was originally developed at Facebook in 2007. Subsequently, it was donated to the Apache Software Foundation. Thrift supports a rich set of types and data structures, and abstracts away transport and protocol details, which lets developers focus on application logic.

As its name suggests, Thrift is designed to be lightweight and efficient. While saving IoT developers from writing lots of boilerplate, the code size can remain tight to fit in embedded platforms. Moreover, Thrift's cross-language capability allows the client and the server be written in different languages. Developers are not limited to use C or C++, and can drive the application with their favourite technology.

Getting Started

Before getting started, make sure you have a proper Zephyr development environment by following the official Zephyr Getting Started Guide.

Then, copy 99-thrift.yaml in this repository to zephyrproject/zephyr/submanifests/, and run west update again:

cat << EOF > submanifests/99-thrift.yaml
manifest:
  defaults:
    remote: upstream

  remotes:
    - name: upstream
      url-base: https://github.com/zephyrproject-rtos

  projects:
    - name: gsoc-2022-thrift
      path: modules/lib/thrift
      revision: main
      submodules: true
EOF
west update

Installing Thrift Binary

MacOS

brew install thrift

Ubuntu

apt install -y libboost-all-dev thrift-compiler libthrift-dev

Supported Features

• Low-Level Transports: Domain, Socket, TLS
• Transport Wrappers: Buffer, Zlib
• Protocols: Binary, Compact
• Servers: Simple

Incompatibilities with Standard APIs

MbedTLS is used in this module to replace the original OpenSSL TLS implementation, which leads to some inconsistency with the standard Thrift APIs:

• SSLv3 is not supported
• TSSLSocketFactory::ciphers() takes no effect: all ciphersuites available in the system is allowed
• Loading certificates and keys from files is not supported

Sample and Tests

hello.thrift in this repository is a good start for getting familiar with the Thrift IDL:

service Hello {
    void ping();
    string echo(1: string msg);
    i32 counter();
}

It describes a service Hello with 3 methods. The first one takes no argument and returns no value. The second one has a string-type argument and returns a string. The third one takes no argument and returns a 32-bit integer.

The sample application includes a client a server which implemented the service above. The client-side code is under samples/lib/thrift/hello_client and the server is under samples/lib/thrift/hello_server. See the documentation of the sample for more information.