How to achieve repeateable results with --seed parameter.

[tboloo]

Hey,
I'm trying to achieve the repeatable results with --seed parameter. If I undersand correctly, toxicity of a given proxy is applied when foloowing condition is met:

...
randomToxicity := rand.Float32() // #nosec G404 -- was ignored before too
	if randomToxicity < toxic.Toxicity {
		toxic.Pipe(s)
        } else {
		new(NoopToxic).Pipe(s)
	}
...

now, for Seed = 1, rand.Float32() gives 0.6046603, so for a toxicity smaller then that is should always go through NoopToxic, however that does not seem to be a case.
I've configured a simple http proxy, and gave it the following toxic:

{
    "proxy_1": {
        "name": "proxy_1",
        "listen": "[::]:8080",
        "upstream": "web-test:8000",
        "enabled": true,
        "Logger": {},
        "toxics": [
            {
                "attributes": {
                    "timeout": 1
                },
                "name": "timeout_1",
                "type": "timeout",
                "stream": "downstream",
                "toxicity": 0.5
            }
        ]
    }
}

and I'd expect it to always pass, however it's not the case:

and toxiproxy logs show

{"level":"warn","name":"proxy_1","listen":"0.0.0.0:8080","upstream":"web-test:8000","bytes":226,"error":"writeto tcp 172.19.0.2:8080->172.19.0.1:37694: read tcp 172.19.0.2:8080->172.19.0.1:37694: use of closed network connection","caller":"link.go:127","time":"2024-12-24T06:48:23Z","message":"Source terminated"}

what am I missing here?

[tboloo]

OK, I think I figured it out. Since go 1.20 one cannot initialize seed for a global random number generator using rand.Seed(seed).
Instead, one needs to re-use locally initialized generator, r := rand.New(rand.NewSource(some_seed)) (...) someRandom := r.Float32()
I've created a PR to fix the bahviour, as currently setting cli flag seed does nothing