Service Behavior Specification¶

Telestion services can be written in any language that supports the NATS protocol.

While there can be differences in the implementation, there are some things that all Telestion services should have in common. This includes, among other things, the configuration of services, allowing seamless deployment of services written in different languages.

Gherkin¶

To specify these common behaviors, we use Gherkin. Gherkin is a language that is used to specify the behavior of software in a human-readable way while still being executable, meaning that tests can be automated.

They are based on examples and should be written in a way that is independent of the implementation language.

The Gherkin files are located in the backend-features directory of the Telestion project.

Documentation¶

The Gherkin files get converted to Markdown files that are then included in the documentation.

Testing¶

Architecture¶

graph TD
    R[Test Runner]
    subgraph Docker
        T[Testbed Container]
        N[NATS Container]
        T --- W[Network] -- Host: nats --- N
    end
    NC[Temporary NATS Config File]
    NC -- mounted into --- N
    R -- writes --> NC
    R -- runs --> T
    T -- result --> R
    R -- controls containers of --> W
    R -- starts/restarts --> N

graph LR
    I[Testbed Image]
    R[Test Runner]
    subgraph Docker 
        C[Testbed Container]
    end
    R -- builds --> I
    R -- runs --> C
    C -- result --> R
    C -- is based on --> I

Natively¶

Create the Python virtual environment with the helper script:

./tools/setup-venv.sh

Source the virtual environment:

. .venv/bin/activate

Run the tests with:

./run-tests.py ./sample-service

[!NOTE] You can also run the tests from any other directory.

[!NOTE] Run ./run-tests.py --help for more options, such as verbose output.