See what we documented at https://github.com/ooni/spec/pull/257
Reference issue: https://github.com/ooni/probe/issues/2238
See also the related ooni/spec PR: https://github.com/ooni/spec/pull/257
See also https://github.com/ooni/probe/issues/2237
While there, bump webconnectivity@v0.5 version because this change
has an impact onto the generated data format.
The drop in coverage is unavoidable because we've written some
tests for `measurex` to ensure we deal with DNS resolvers and transport
names correctly depending on the splitting policy we use.
(However, `measurex` is only used for the `tor` experiment and, per
the step-by-step design document, new experiments should use
`measurexlite` instead, so this is hopefully fine(TM).)
While there, fix a broken integration test that does not run in `-short` mode.
* feat(dnsovergetaddrinfo): collect the CNAME
This diff modifies how dnsovergetaddrinfo.go works such that the
returned DNSResponse includes the CNAME.
Closes https://github.com/ooni/probe/issues/2226.
While there, recognize that we can remove getaddrinfoLookupHost and
always call getaddrinfoLookupANY everywhere. (This simplification is
why we did https://github.com/ooni/probe-cli/pull/874.)
* fix: extra debugging because of failing CI
Everything is OK locally (on macOS). However, maybe things are a bit
different on GNU/Linux perhaps?
Here's the error:
```
--- FAIL: TestPass (0.11s)
resolver_test.go:113: unexpected rcode
FAIL
coverage: 95.7% of statements
FAIL github.com/ooni/probe-cli/v3/internal/cmd/jafar/resolver 0.242s
```
I'm a bit confused because jafar's resolver is _unrelated_. But actually this
error never occurred again after a committed the debugging diff.
After https://github.com/ooni/probe-cli/pull/764, the build for
CGO_ENABLED=0 has been broken for miniooni:
https://github.com/ooni/probe-cli/runs/6636995859?check_suite_focus=true
Likewise, it's not possible to run tests with CGO_ENABLED=0.
To make tests work with `CGO_ENABLED=0`, I needed to sacrifice some
unit tests run for the CGO case. It is not fully clear to me what was happening
here, but basically `getaddrinfo_cgo_test.go` was compiled with CGO
being disabled, even though the ``//go:build cgo` flag was specified.
Additionally, @hellais previously raised a valid point in the review
of https://github.com/ooni/probe-cli/pull/698:
> Another issue we should consider is that, if I understand how
> this works correctly, depending on whether or not we have built
> with CGO_ENABLED=0 on or not, we are going to be measuring
> things in a different way (using our cgo inspired getaddrinfo
> implementation or using netgo). This might present issues when
> analyzing or interpreting the data.
>
> Do we perhaps want to add some field to the output data format that
> gives us an indication of which DNS resolution code was used to
> generate the the metric?
This comment is relevant to the current commit because
https://github.com/ooni/probe-cli/pull/698 is the previous
iteration of https://github.com/ooni/probe-cli/pull/764.
So, while fixing the build and test issues, let us also distinguish
between the CGO_ENABLED=1 and CGO_ENABLED=0 cases.
Before this commit, OONI used "system" to indicate the case where
we were using net.DefaultResolver. This behavior dates back to the
Measurement Kit days. While it is true that ooni/probe-engine and
ooni/probe-cli could have been using netgo in the past when we
said "system" as the resolver, it also seems reasonable to continue
to use "system" top indicate getaddrinfo.
So, the choice here is basically to use "netgo" from now on to
indicate the cases in which we were built with CGO_ENABLED=0.
This change will need to be documented into ooni/spec along with
the introduction of the `android_dns_cache_no_data` error.
## Checklist
- [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md)
- [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2029
- [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/242
