Using proxy for Insights

[micsjo]

Using k6 locally in a restricted network and sending data to Load Impact Insights or the "-o cloud" option is a very good solution.

However, restricted network often means internet access (if any) is usually by proxy.

We would like to have a way to specify a proxy for the cloud (or Insights) output only that will not impact the requests generated.

[na--]

It should be fairly simple to just add a proxy config option for the Load Impact Insights output, via a K6_CLOUD_PROXY environment variable or something like that. But then, are we going to have to repeat this exercise for every single output, since it could be argued that there's a similar use case for them as well? That would definitely be cumbersome and would exacerbate the current configuration issues (#883, #587)...

A workaround (that's also far from ideal) when we have the custom transports would be to set a global proxy via HTTP_PROXY environment variable (that would be used by the outputs) and an explicit no-proxy transport for the actual load test.

[micsjo]

You could honor the NO_PROXY header as well, such as curl does it curl proxy headers

[na--]

Hm it actually seems like we already do! We use the http.ProxyFromEnvironment and it seems to support NO_PROXY:

ProxyFromEnvironment returns the URL of the proxy to use for a given request, as indicated by the environment variables HTTP_PROXY, HTTPS_PROXY and NO_PROXY (or the lowercase versions thereof). HTTPS_PROXY takes precedence over HTTP_PROXY for https requests.
...
A nil URL and nil error are returned if no proxy is defined in the environment, or a proxy should not be used for the given request, as defined by NO_PROXY.

[micsjo]

I noticed when I was looking into the code that you were using the standard golang implementation for the proxy settings which includes the NO_PROXY setting. I have just validated that it works as expected.

So this issue is simpler than fixing code, it's apparently enough to fix the documentation :-)

[na--]

Yep, tagged it as such 👍 😄 Thanks again!

[na--]

Closing this in favor of grafana/k6-docs#74, given that the docs now live in their own repo.