Creating a toxic for an existent proxy gives an exception

[joaoasrosa]

Issue
I'm trying to add an experiment to the catalogue. The idea is to use toxiproxy, and proxy the calls to a mysql database. With that, I can control the type of faults that would be injected,
The environment is on AWS: toxiproxy in a ubuntu machine, and mysql in a rds instance. The app is .net core (not relevant) and exposes a REST API.

The experiment verifies the steady-state (one of the API endpoints) and then creates a toxic. The proxy is already created, due to the fact that the app needs to connect to it.
However, when trying to create the toxic, there is an error:

[2019-10-21 09:47:38 ERROR] [toxiproxyapi:68] Unable to create toxic for proxy: mysql

Digging into that, I used postman to post the same payload to the endpoint. The payload generated by the chaostollokit extensions:

[2019-10-21 09:47:38 INFO] [actions:39] Creating toxy mysql-latency for proxy mysql with type: latency as a downstream with toxicity 1.0 and attributes {'latency': '1234', 'jitter': '89'}

Extracting the full payload (on my environment added a line to output the json), looks like this:

[2019-10-21 09:47:38 DEBUG] [actions:46] json format for toxy creation: {'name': 'mysql-latency', 'type': 'latency', 'stream': 'downstream', 'toxicity': 1.0, 'attributes': {'latency': '1234', 'jitter': '89'}}

Using the same payload on postman, I get the full error:

{"error":"bad request body: json: cannot unmarshal string into Go struct field LatencyToxic.latency of type int64","status":400}

Although the attributes are of type int (from what I got in the code), when parsed to json transforms into string. Toxiproxy is picky with the types.

Environment

• Toxiproxy
  • Version: 2.1.4
  • OS: Ubuntu
• Chaostoolkit
  • Version 1.3.0
  • OS: Cataliana 10.15

[dimzak]

Hi @joaoasrosa!
Can you try the same experiment without the single quotes in latency and maybe in jitter too like:

{
  latency:1234, 
  jitter:89
}

If issue still persists, can you also add here the method used to create above toxic?

[joaoasrosa]

The snippet of the experiment looks like:

"method": [
        {
            "name": "create_latency_toxic",
            "provider": {
                "arguments": {
                    "for_proxy": "${toxiproxy_proxy_name}",
                    "toxic_name": "${toxiproxy_proxy_name}-latency",
                    "latency": "${toxiproxy_toxic_latency}",
                    "jitter": "${toxiproxy_toxic_jitter}"
                },
                "func": "create_latency_toxic",
                "module": "chaostoxi.toxic.actions",
                "type": "python"
            },
            "type": "action",
            "pauses": {
                "after": 1
            }
        },

The parameters came from the environment variables. I will do an experiment with hardcoded values to check the result.

[joaoasrosa]

Using hardcore parameters in the method:

"method": [
        {
            "name": "create_latency_toxic",
            "provider": {
                "arguments": {
                    "for_proxy": "${toxiproxy_proxy_name}",
                    "toxic_name": "${toxiproxy_proxy_name}-latency",
                    "latency": 1200,
                    "jitter": 100
                },
                "func": "create_latency_toxic",
                "module": "chaostoxi.toxic.actions",
                "type": "python"
            },
            "type": "action",
            "pauses": {
                "after": 1
            }
        },

The toxic is created, and the chaos experiment contiue the execution.

[Lawouach]

Unfortunately, one of the limitation of parametrization is that it will always render as a string a variable. Maybe this be considereda bug in the toolkit?

[joaoasrosa]

I'm happy to follow that path. An interesting observation from the code (I'm not a Python expert):

def create_latency_toxic(for_proxy: str, toxic_name: str, latency: int,
                         jitter: int = 0,
                         configuration: Configuration = None) -> Dict[str, Any]:
    """
    Add a delay to all data going through the proxy using a downstream
    with a toxicity of 100%.
    """
    attributes = {
        "latency": latency,
        "jitter": jitter
    }
    return create_toxic(for_proxy=for_proxy, toxic_name=toxic_name,
                        toxic_type='latency', attributes=attributes,
                        configuration=configuration)

The function parameters are defined as int. From that, it's a dictionary of string, Any.

[dimzak]

@Lawouach do you think this issue should be addressed in chaostoolkit repo as it might bite other extensions too?

[Lawouach]

Yes, definitely!

Here it is :) chaostoolkit/chaostoolkit-lib#137