Expand README

Author: lunkwill42

README.rst

@@ -14,7 +14,7 @@ pytest-argus-server
     :target: https://github.com/Uninett/pytest-argus-server/actions/workflows/main.yml
     :alt: See Build Status on GitHub Actions
 
-A plugin that provides a running Argus API server for tests
+A `pytest`_ plugin that provides a running `Argus`_ API server for tests.
 
 ----
 
@@ -24,14 +24,12 @@ This `pytest`_ plugin was generated with `Cookiecutter`_ along with `@hackebrot`
 Features
 --------
 
-* TODO
-
+* Fixtures that will provide tests with a running Argus API server (using Docker Compose)
 
 Requirements
 ------------
 
-* TODO
-
+* `Docker Compose`_
 
 Installation
 ------------
@@ -44,7 +42,32 @@ You can install "pytest-argus-server" via `pip`_ from `PyPI`_::
 Usage
 -----
 
-* TODO
+Installing this package will automatically make it available in `pytest`_.
+
+Extra pytest command line arguments
++++++++++++++++++++++++++++++++++++
+
+By default, this plugin will run the *latest available* Argus server Docker
+image.  The actually deployed version can be controlled by adding the
+``--argus-version`` command line option to pytest::
+
+  pytest --argus-version=1.30.0 tests/
+
+Provided fixtures
++++++++++++++++++
+
+The main fixture provided by this plugin is the session-scoped ``argus_api``.
+When used by a test, this will ensure an Argus server is running with a
+pre-made test incident source and API token, and ready to take requests.  It
+returns a two-tuple value that provides a URL to the running API and a valid
+API token that can be used by the test:
+
+.. code-block:: python
+
+    def test_url_should_be_as_expected(argus_api):
+        url, token = argus_api
+        assert url == "http://localhost:8000/api/v2"
+
 
 Contributing
 ------------
@@ -62,6 +85,8 @@ Issues
 
 If you encounter any problems, please `file an issue`_ along with a detailed description.
 
+.. _`Argus`: https://github.com/Uninett/argus
+.. _`Docker Compose`: https://docs.docker.com/compose/
 .. _`Cookiecutter`: https://github.com/audreyr/cookiecutter
 .. _`@hackebrot`: https://github.com/hackebrot
 .. _`MIT`: https://opensource.org/licenses/MIT