Heads up: Making connections now disallowed in tests

[lzap]

Hello,

we enabled webmock over the weekend in core tests. This means that everytime a unit, functional, integration or any test in core attempts to make a HTTP or HTTPS connection it will be disallowed and test will fail with handy explanation of what happened and how to stub the request.

However, do not use stub_request method directly and prefer stubs/expects from mocha library on top of our Proxy API classes. We tend to connect to external services via common API which is a good design pattern to follow. There are places where stub_request might be appropriate, but we should minimize those - there are currently two uses in the whole codebase.

There is one exception - localhost and 127.0.0.1 addresses are whitelisted, because integration tests use them. This means that when writing tests prefer some dummy hostnames to localhost so we error out early. I’ve seen many dummy hostnames in the codebase, the golden rules are:

• do not use localhost or 127.0.0.1
• use existing domain but non-existing host which does not resolve fast (e.g. dummyproxy.theforeman.org)
• prefer mocha stubs to webmock stubs

I have a hope that this will bring number of random failures to minimum, I fixed several tests which were actually doing requests (which failed). Few tests were actually incorrect - those expecting a failure of different kind. We will see if there are less random failures. Thanks.

https://github.com/theforeman/foreman/pull/5445

More info about webmock (keep in mind we utilize it rather to fail early than using the stubbing mechanism):

GitHub - bblimke/webmock: Library for stubbing and setting expectations on...

[ekohl]

Hurray for this.

do not use localhost or 127.0.0.1

If you need to use IP’s the follow RFC 5735:

192.0.2.0/24 - This block is assigned as “TEST-NET-1” for use in documentation and example code. It is often used in conjunction with domain names example.com or example.net in vendor and protocol documentation. As described in [RFC5737], addresses within this block do not legitimately appear on the public Internet and can be used without any coordination with IANA or an Internet registry. See [RFC1166].

There are actually 3 of these networks:

• TEST-NET-1 192.0.2.0/24
• TEST-NET-2 198.51.100.0/24
• TEST-NET-3 203.0.113.0/24

Do not use RFC1918 (NAT) IP’s since they might exist on a developers network.

use existing domain but non-existing host which does not resolve fast (e.g. dummyproxy.theforeman.org)

Personally I prefer example.{com,org,net} per RFC2606. We can actually use things on theforeman.org and we could accidentally create something overlapping.

[lzap]

Nice comment about those test IPs and hostname, I was not aware of this. If we had “How to write tests” document I vote adding it there.

Anyone is welcome to rewrite all our hostnames in tests to xxx.example.com and IPs as well.