ts-legalcheck 1.1.2

TrustSource Legal Check tool.

TS-Legalcheck

ts-legalcheck is a tool for automatically checking legal obligations and violations related to the use of software components licensed under one or more open-source licenses within a project. It consists of a powerful constraints engine leveraging the state-of-the-art SMT solver Z3 and several flexible and easily extendable sets of rules describing constraints and definitions extracted from various open-source licenses. The internal format for constraints and definitions allows formal definitions without limitations, enabling not only switching between different models but also combining them. One great example is the use of the OSADL checklists, available as a model for ts-legalcheck, together with a set of violation rules developed by EACG GmbH.

Introduction

The following diagram represents the main functional principle of ts-legalcheck. The tool accepts as input a model consisting of data extracted from open-source licenses. It contains known rights, obligations, and terms, as well as different rules describing in which situations certain obligations apply and, for example, which conditions may violate license usage.

Besides a model, the ts-legalcheck engine also expects user input describing the legal settings of a project, which define different aspects such as distribution model, distribution form, or modification of third-party components used in the project. We refer to such input as a use case or legal situation. Based on the model, legal settings, and the set of open-source licenses used in the project, the engine decides whether the usage of certain licenses is possible in the provided use case and, if so, provides a set of obligations that must be fulfilled.

The different models created by EACG GmbH can be found in the data/LicenseConstraints_vX.[json|toml] files, and the OSADL model in the data/osadl/LicenseConstraints_v1.0.toml file.

Installation

ts-legalcheck is available as a PyPI package as well as a ready-to-use Docker image.

PyPI

Requirements: Python >= 3.10

pip install ts-legalcheck

Docker

docker pull trustsource/ts-legalcheck

Usage

Installed via PyPI

When ts-legalcheck is installed from PyPI, it can be used directly as a command-line tool from the shell.

License Test

The test command is used to check whether a use case violates license usage and, if not, provides a list of obligations that must be fulfilled:

ts-legalcheck test -l <LICENSE> -d <MODEL LOCATION> <USE-CASE LOCATION> 

Example:

The following example tests if the Apache-2.0 license can be used in a project with the legal settings from examples/sc01_ProprietarySoftware.toml and, if so, which obligations must be fulfilled.

ts-legalcheck test -l Apache-2.0 -d data/LicenseConstraints_v4.5.toml examples/sc01_ProprietarySoftware.toml

Installed as a Docker image

When ts-legalcheck is pulled as a Docker image, it can be executed within a Docker container. For example, the previous example can be executed using Docker as follows:

docker run -it --rm -v ./examples:/examples trustsource/ts-legalcheck test -l Apache-2.0 -d /data/LicenseConstraints_v4.5.toml /examples/sc01_ProprietarySoftware.toml

NOTE: No extra installation step is required; by executing this command, the ts-legalcheck image is pulled automatically.