sarvex / rego-cpp

A C++ interpreter for the OPA policy language Rego

rego-cpp

This project is an effort to create a C++ interpreter for the OPA policy language, Rego. Our goal is to build both a standalone executable and a library such that programmers who are working in C++ can interpret Rego programs natively. To achieve this we are building our interpereter on top of the experimental term rewriter Trieste.

Warning This project is still in the early stages, and we do not currently support many language features.

Getting Started

First you will need to install the build dependencies in the manner appropriate to your system:

1. cmake
2. ninja (optional)
3. clang++ (optional)
4. clang-format (optional)

Note 2-4 are entirely optional (i.e. the build does not require them) but will produce the most reliable results. Our CI currently tests the following configurations:

1. Windows latest with MSBuild
2. Ubuntu latest with Ninja/Clang

Create a build directory and initialize the cmake project:

mkdir build
cd build
cmake .. -DCMAKE_INSTALL_PREFIX=dist

You can then build and run the tests using:

cmake --build . --config Debug --target INSTALL
ctest -C Debug

If you wish to use Ninja, then be sure to pass -G Ninja as well when configuring the project. Then:

ninja install
ctest -C Debug

Similarly, if you want to use clang you can indicate this by passing -DCMAKE_CXX_COMPILER=clang++ during configuration.

The interpreter will be located at build/dist/bin/rego_interpreter. Here are some example commands using the provided example files:

./bin/rego_interpreter -d examples/scalars.rego -q data.scalars.greeting
"Hello"

./bin/rego_interpreter -d examples/objects.rego -q data.objects.sites[1].name
"smoke1"

./bin/rego_interpreter -d examples/data0.json -d examples/data1.json -d examples/objects.rego -d examples/input.json  -q "[data.one, input.b, data.objects.sites[data.objects.index]]"
[{"bar": "Foo", "baz": 5, "be": true, "bop": 23.4}, undefined, {"name": "smoke1"}]

./bin/rego_interpreter -q "5 + (2 - 4 * 0.25) * -3 + 7.4"
9.4

./bin/rego_interpreter -d examples/bodies.rego -q data.bodies.e
{"one": 15, "two": 15}

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

This project may contain trademarks or logos for projects, products, or services. Authorized use of Microsoft trademarks or logos is subject to and must follow Microsoft's Trademark & Brand Guidelines. Use of Microsoft trademarks or logos in modified versions of this project must not cause confusion or imply Microsoft sponsorship. Any use of third-party trademarks or logos are subject to those third-party's policies.