## 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/2158
- [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/250
## Description
This diff refactors the codebase to reimplement tlsping and tcpping
to use the step-by-step measurements style.
See docs/design/dd-003-step-by-step.md for more information on the
step-by-step measurement style.
This diff refactors the DNSTransport model to receive in input a DNSQuery and return in output a DNSResponse.
The design of DNSQuery and DNSResponse takes into account the use case of a transport using getaddrinfo, meaning that we don't need to serialize and deserialize messages when using getaddrinfo.
The current codebase does not use a getaddrinfo transport, but I wrote one such a transport in the Websteps Winter 2021 prototype (https://github.com/bassosimone/websteps-illustrated/).
The design conversation that lead to producing this diff is https://github.com/ooni/probe/issues/2099
This diff has been extracted from c2f7ccab0e
See https://github.com/ooni/probe/issues/2096
While there, export DecodeReply to decode a raw reply without
interpreting the Rcode or parsing the results, which seems a
nice extra feature to have to more flexibly parse DNS replies
in other parts of the codebase.
This diff re-implements the vanilla_tor experiment. This experiment was
part of the ooni/probe-legacy implementation.
The reference issue is https://github.com/ooni/probe/issues/803. We didn't
consider the possible improvements mentioned by the
https://github.com/ooni/probe/issues/803#issuecomment-598715694 comment,
which means we'll need to create a follow-up issue for them. We will
then decide whether, when, and how to implement those follow-up measurements
either into `vanilla_tor` or into the existing `tor` experiment.
This novel `vanilla_tor` implementation emits test_keys that are mostly
compatible with the original implementation, however:
1. the `timeout` is a `float64` rather than integer (but the default
timeout is an integer, so there are no JSON-visible changes);
2. the `tor_log` string is gone and replaced by the `tor_logs` list
of strings, which contains the same information;
3. the definition of `error` has been augmented to include the
case in which there is an unknown error;
4. the implementation of vanilla_tor mirrors closely the one of torsf
and we have taken steps to make the two implementations as comparable
as possible in terms of the generated JSON measurement.
The main reason why we replaced `tor_log` with `tor_logs` are:
1. that `torsf` already used that;
2. that reading the JSON is easier with this implementation compared to
an implementation where all logs are into the same string.
If one is processing the new data format using Python, then it will
not be difficult convert `tor_log` to `tor_logs`. In any case, because
we extract the most interesting fields (e.g., the percentage of the
bootstrap where tor fails), it seems that logs are probably more useful
as something you want to read in edge cases (I guess).
Also, because we want `torsf` and `vanilla_tor` to have similar JSONs,
we renamed `torsf`'s `default_timeout` to `timeout`. This change has little
to none real-world impact, because no stable version of OONI Probe has
ever shipped a `torsf` producing the `default_timeout` field.
Regarding the structure of this diff, we have:
1. factored code to parse tor logs into a separate package;
2. implemented `vanilla_tor` as a stripped down `torsf` and added further
changes to ensure compatibility with the previous `vanilla_tor`'s data format;
3. improved `torsf` to merge back the changes in `vanilla_tor`, so the two
data formats of the two experiments are as similar as possible.
We believe producing as similar as possible data formats helps anyone who's
reading measurements generated by both experiments.
We have retained/introduced `vanilla_tor`'s `error` field, which is not very
useful when one has a more precise failure but is still what `vanilla_tor`
used to emit, so it makes sense to also have this field.
In addition to changing the implementation, we also updated the specs.
As part of our future work, we may want to consider factoring the common code
of these two experiments into the same underlying support library.
* quic-go upgrade: replaced Session/EarlySession with Connection/EarlyConnection
* quic-go upgrade: added context to RoundTripper.Dial
* quic-go upgrade: made corresponding changes to tutorial
* quic-go upgrade: changed sess variable instances to qconn
* quic-go upgrade: made corresponding changes to tutorial
* cleanup: remove unnecessary comments
Those comments made sense in terms of illustrating the changes
but they're going to be less useful once we merge.
* fix(go.mod): apparently we needed `go1.18.1 mod tidy`
VSCode just warned me about this. It seems fine to apply this
change as part of the pull request at hand.
* cleanup(netxlite): http3dialer can be removed
We used to use http3dialer to glue a QUIC dialer, which had a
context as its first argument, to the Dial function used by the
HTTP3 transport, which did not have a context as its first
argument.
Now that HTTP3 transport has a Dial function taking a context as
its first argument, we don't need http3dialer
anymore, since we can use the QUIC dialer directly.
Cc: @DecFox
* Revert "cleanup(netxlite): http3dialer can be removed"
This reverts commit c62244c620cee5fadcc2ca89d8228c8db0b96add
to investigate the build failure mentioned at
https://github.com/ooni/probe-cli/pull/715#issuecomment-1119450484
* chore(netx): show that test was already broken
We didn't see the breakage before because we were not using
the created transport, but the issue of using a nil dialer was
already present before, we just didn't see it.
Now we understand why removing the http3transport in
c62244c620cee5fadcc2ca89d8228c8db0b96add did cause the
breakage mentioned at
https://github.com/ooni/probe-cli/pull/715#issuecomment-1119450484
* fix(netx): convert broken integration test to working unit test
There's no point in using the network here. Add a fake dialer that
breaks and ensure we're getting the expected error.
We've now improved upon the original test because the original test was
not doing anything while now we're testing whether we get back a QUIC
dialer that _can be used_.
After this commit, I can then readd the cleanup commit
c62244c620cee5fadcc2ca89d8228c8db0b96add and it won't be
broken anymore (at least, this is what I expected to happen).
* Revert "Revert "cleanup(netxlite): http3dialer can be removed""
This reverts commit 0e254bfc6ba3bfd65365ce3d8de2c8ec51b925ff
because now we should have fixed the broken test.
Co-authored-by: decfox <decfox>
Co-authored-by: Simone Basso <bassosimone@gmail.com>
This diff introduces a new package called `./internal/archival`. This package collects data from `./internal/model` network interfaces (e.g., `Dialer`, `QUICDialer`, `HTTPTransport`), saves such data into an internal tabular data format suitable for on-line processing and analysis, and allows exporting data into the OONI data format.
The code for collecting and the internal tabular data formats are adapted from `measurex`. The code for formatting and exporting OONI data-format-compliant structures is adapted from `netx/archival`.
My original objective was to _also_ (1) fully replace `netx/archival` with this package and (2) adapt `measurex` to use this package rather than its own code. Both operations seem easily feasible because: (a) this code is `measurex` code without extensions that are `measurex` related, which will need to be added back as part of the process; (b) the API provided by this code allows for trivially converting from using `netx/archival` to using this code.
Yet, both changes should not be taken lightly. After implementing them, there's need to spend some time doing QA and ensuring all nettests work as intended. However, I am planning a release in the next two weeks, and this QA task is likely going to defer the release. For this reason, I have chosen to commit the work done so far into the tree and defer the second part of this refactoring for a later moment in time. (This explains why the title mentions "1/N").
On a more high-level perspective, it would also be beneficial, I guess, to explain _why_ I am doing these changes. There are two intertwined reasons. The first reason is that `netx/archival` has shortcomings deriving from its original https://github.com/ooni/netx legacy. The most relevant shortcoming is that it saves all kind of data into the same tabular structure named `Event`. This design choice is unfortunate because it does not allow one to apply data-type specific logic when processing the results. In turn, this choice results in complex processing code. Therefore, I believe that replacing the code with event-specific data structures is clearly an improvement in terms of code maintainability and would quite likely lead us to more confidently change and evolve the codebase.
The second reason why I would like to move forward these changes is to unify the codepaths used for measuring. At this point in time, we basically have two codepaths: `./internal/engine/netx` and `./internal/measurex`. They both have pros and cons and I don't think we want to rewrite whole experiments using `netx`. Rather, what we probably want is to gradually merge these two codepaths such that `netx` is a set of abstractions on top of `measurex` (which is more low-level and has a more-easily-testable design). Because saving events and generating an archival data format out of them consists of at least 50% of the complexity of both `netx` and `measurex`, it seems reasonable to unify this archival-related part of the two codebases as the first step.
At the highest level of abstraction, these changes are part of the train of changes which will eventually lead us to bless `websteps` as a first class citizen in OONI land. Because `websteps` requires different underlying primitives, I chose to develop these primitives from scratch rather than wrestling with `netx`, which used another model. The model used by `websteps` is that we perform each operation in isolation and immediately we save the results, while `netx` creates whole data structures and collects all the events happening via tracing. We believe the model used by `websteps` to be better because it does not require your code to figure out everything that happened after the measurement, which is a source of subtle bugs in the current implementation. So, when I started implementing websteps I extracted the bits of `netx` that could also be beneficial to `websteps` into a separate library, thus `netxlite` was born.
The reference issue describing merging the archival of `netx` and `measurex` is https://github.com/ooni/probe/issues/1957. As of this writing the issue still references the original plan, which I could not complete by the end of this Sprint, so I am going to adapt the text of the issue to only refer to what was done in here next. Of course, I also need follow-up issues.
## 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
