Parametrized LoadTestShape

It’d be nice if we were able to parametrize custom LoadTestShapes. For example control peak number of users or test duration as a whole.

Is your feature request related to a problem? Please describe.

I want to measure resources utilization for different amount of users. To achieve that I’ve prepared usage characteristics from our logs and want to see how much more users we can support with current hardware. To do that I want to test my service with different peak user counts - e.g. 1k, 2k, 3k, etc. For now it’s really frustrating to do because I always need to change that value in file.

Describe the solution you’d like

I’d be nice if we were able to access some kind of context information from LoadTestShape that could contain configuration in form of simple dictionary. e.g.

def tick(self):
    max_users = self.context.parameters['max_users']
    ...

Parameters could be set via HTTP form <input name="load_parameter[max_users]" /> or CLI parameter: --load-parameter max_users=200.

HTTP form could be changed by wraping it with some block and thus allowing to easily overwrite it with custom form.

Describe alternatives you’ve considered

For CLI usage probable environment variables would be good enough, but for HTTP it’s not really viable - especially because we’re using k8s.

[kadet1090]

I tought more about being able to overwrite actual form and provide our own html (via template extending, for example, or some other way):

{% extend 'path/to/templates/index.html' %}

{% block swarm_form %}
    <label for="peak_count">Number of peak users to simulate</label>
    <input type="text" name="parameter[peak_count]" id="peak_count" value="1000" class="val"/><br>
    <label for="total_time">Total time of the load (in seconds)</label>
    <input type="text" name="parameter[total_time]" id="total_time" value="600" class="val"/><br>
{% endblock %}

And it would look like this:

It’d require change to templates/index.html by wraping it with {% block swarm_form %}{% endblock %}. Then everything that was sent by form inside parameter dictionary should be accessible to LoadTestShape.

By default we could of course just display <textarea name="parameter[data]"></textarea> that could be parsed - so if someone for any reason don’t want to be bothered with HTML modification.

I could try to achieve something like that in free time, and give you some kind of response how hard was to implement that (eventually submit PR if it’d be good enough) 😃

[max-rocket-internet]

OK I see. Sounds good. There was some previous PR IIRC about making the UI more editable.