This diff implements the first two cleanups defined at https://github.com/ooni/probe/issues/1956:
> - [ ] observe that `netxlite` and `netx` differ in error wrapping only in the way in which we set `ErrWrapper.Operation`. Observe that the code using `netxlite` does not care about such a field. Therefore, we can modify `netxlite` to set such a field using the code of `netx` and we can remove `netx` specific code for errors (which currently lives inside of the `./internal/engine/legacy/errorsx` package
>
> - [ ] after we've done the previous cleanup, we can make all the classifiers code private, since there's no code outside `netxlite` that needs them
A subsequent diff will address the remaining cleanup.
While there, notice that there are failing, unrelated obfs4 tests, so disable them in short mode. (I am confident these tests are unrelated because they fail for me when running test locally from the `master` branch.)
1. we want optionally to log the body (we don't want to log the body
when we're fetching psiphon secrets or tor targets)
2. we want body logging to _also_ happen on error since this is quite
useful to debug possible errors when accessing the API
This diff adds the above functionality, which were previously
described in https://github.com/ooni/probe/issues/1951.
This diff also adds comprehensive testing.
As mentioned in https://github.com/ooni/probe/issues/1951, one of
the main issues I did see with httpx.APIClient is that in some cases
it's used in a very fragile way by probeservices.Client.
This happens in psiphon.go and tor.go, where we create a copy of
the APIClient and then modify it's Authorization field.
If we ever refactor probeservices.Client to take a pointer to
httpx.Client, we are now mutating the httpx.Client.
Of course, we don't want that to happen.
This diff attempts to address such a problem as follows:
1. we create a new APIClientTemplate type that holds the same
fields of an APIClient and allows to build an APIClient
2. we modify every user of APIClient to use APIClientTemplate
3. when we need an APIClient, we build it from the corresponding
template and, when we need to use a specific Authorization, we
use a build factory that sets APIClient.Authorization
4. we hide APIClient by renaming it apiClient and by defining
an interface called APIClient that allows to use it
So, now the codebase always uses the opaque APIClient interface to
issue API calls and always uses the APIClientTemplate to build an
opaque APIClient.
Boom! We have separated construction from usage and we are not
mutating in weird ways the APIClient anymore.
This PR starts to implement the refactoring described at https://github.com/ooni/probe/issues/1951. I originally wrote more patches than the ones in this PR, but overall they were not readable. Since I want to squash and merge, here's a reasonable subset of the original patches that will still be readable and understandable in the future.
## 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/1885
- [x] related ooni/spec pull request: N/A
Location of the issue tracker: https://github.com/ooni/probe
## Description
This PR contains a set of changes to move important interfaces and data types into the `./internal/model` package.
The criteria for including an interface or data type in here is roughly that the type should be important and used by several packages. We are especially interested to move more interfaces here to increase modularity.
An additional side effect is that, by reading this package, one should be able to understand more quickly how different parts of the codebase interact with each other.
This is what I want to move in `internal/model`:
- [x] most important interfaces from `internal/netxlite`
- [x] everything that was previously part of `internal/engine/model`
- [x] mocks from `internal/netxlite/mocks` should also be moved in here as a subpackage
When preparing a tutorial for netxlite, I figured it is easier
to tell people "hey, this is the package you should use for all
low-level networking stuff" rather than introducing people to
a set of packages working together where some piece of functionality
is here and some other piece is there.
Part of https://github.com/ooni/probe/issues/1591
We need still to add similar wrappers to internal/netxlite but we
will adopt a saner approach to error wrapping this time.
See https://github.com/ooni/probe/issues/1591
The legacy part for now is internal/errorsx. It will stay there until
I figure out whether it also needs some extra bug fixing.
The good part is now in internal/netxlite/errorsx and contains all the
logic for mapping errors. We need to further improve upon this logic
by writing more thorough integration tests for QUIC.
We also need to copy the various dialer, conn, etc adapters that set
errors. We will put them inside netxlite and we will generate errors in
a way that is less crazy with respect to the major operation. (The
idea is to always wrap, given that now we measure in an incremental way
and we don't measure every operation together.)
Part of https://github.com/ooni/probe/issues/1591
This is the extension of https://github.com/ooni/probe-cli/pull/431, and my final deliverable for GSoC 2021.
The diff introduces:
1) The new `testhelper` which supports testing multiple IP endpoints per domain and introduces HTTP/3 control measurements. The specification of the `testhelper` can be found at https://github.com/ooni/spec/pull/219. The `testhelper` algorithm consists of three main steps:
* `InitialChecks` verifies that the input URL can be parsed, has an expected scheme, and contains a valid domain name.
* `Explore` enumerates all the URLs that it discovers by redirection from the original URL, or by detecting h3 support at the target host.
* `Generate` performs a step-by-step measurement of each discovered URL.
2) A prototype of the corresponding new experiment `websteps` which uses the control measurement of the `testhelper` to know which URLs to measure, and what to expect. The prototype does not yet have:
* unit and integration tests,
* an analysis tool to compare the control and the probe measurement.
This PR is my final deliverable as it is the outcome of the trials, considerations and efforts of my GSoC weeks at OONI.
It fully integrates HTTP/3 (QUIC) support which has been only used in the `urlgetter` experiment until now.
Related issues: https://github.com/ooni/probe/issues/1729 and https://github.com/ooni/probe/issues/1733.