This diff forward ports b6db4f64dc83a2a27ee3ce6bba5ac93db922832d, whose
original log message is the following:
- - -
We're now using ooni/oohttp as our HTTP library in most cases.
A limitation of this library is that net/http/httptrace does not
work very well and reliably because (1) we need to use oohttp's
version of that code and (2) we cannot observe net events.
I noticed this fact because an integration test for collecting
HTTP performance metrics was broken.
The best solution here is to remove this functionality, since
it was basically unused in the repository. Only some integration
tests inside urlgetter bothered with these metrics.
A more clinical fix would have been to use ooni/oohttp/httptrace
instead of net/http/httptrace in the stdlib, but it does not
seem to be a good idea, given that those metrics were not used.
With this diff applied, we'll further reduce the number of locally
failing integration tests to just jafar-specific tests.
This diff WILL need to be forwardported to `master`.
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.
* chore(netxlite): add currently failing test case
This diff introduces a test cases that will fail because of the reason
explained in https://github.com/ooni/probe/issues/1965.
* chore(netxlite/iox_test.go): add failing unit tests
These tests directly show how the Go implementation of ReadAll
and Copy has the issue of checking for io.EOF equality.
* fix(netxlite): make {ReadAll,Copy}Context robust to wrapped io.EOF
The fix is simple: we just need to check for `errors.Is(err, io.EOF)`
after either io.ReadAll or io.Copy has returned. When this condition is
true, we need to convert the error back to `nil` as it ought to be.
While there, observe that the unit tests I committed in the previous
commit are wrongly asserting that the error must be wrapped. This
assertion is not correct, because in both cases we have just ensured
that the returned error is `nil` (i.e., success).
See https://github.com/ooni/probe/issues/1965.
* cleanup: remove previous workaround for wrapped io.EOF
These workarounds were partial, meaning that they would cover some
cases in which the issue occurred but not all of them.
Handling the problem in `netxlite.{ReadAll,Copy}Context` is the
right thing to do _as long as_ we always use these functions instead
of `io.{ReadAll,Copy}`.
This is why it's now important to ensure we clearly mention that
inside of the `CONTRIBUTING.md` guide and to also ensure that we're
not using these functions in the code base.
* fix(urlgetter): repair tests who assumed to see EOF error
Now that we have established that we should normalize EOF when
reading bodies like the stdlib does and now that it's clear why
our behavior diverged from the stdlib, we also need to repair
all the tests that assumed this incorrect behavior.
* fix(all): don't use io{,util}.{Copy,ReadAll}
* feat: add checks to ensure we don't use io.{Copy,ReadAll}
* doc(netxlite): document we know how to deal w/ wrapped io.EOF
* fix(nocopyreadall.bash): add exception for i/n/iox.go
This diff addresses another point of https://github.com/ooni/probe/issues/1956:
> - [ ] observe that we're still using a bunch of private interfaces for common interfaces such as the `Dialer`, so we can get rid of these private interfaces and always use the ones in `model`, which allows us to remove a bunch of legacy wrappers
Additional cleanups may still be possible. The more I cleanup, the more I see
there's extra legacy code we can dispose of (which seems good?).
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
I have recently seen a data race related our way of
mutating the outgoing request to set the host header.
Unfortunately, I've lost track of the race output,
because I rebooted my Linux box before saving it.
Though, after inspecting why and and where we're mutating
outgoing requets, I've found that:
1. we add the host header when logging to have it logged,
which is not a big deal since we already emit the URL
rather than just the URL path when logging a request, and
so we can safely zap this piece of code;
2. as a result, in measurements we may omit the host header
but again this is pretty much obvious from the URL itself
and so it should not be very important (nonetheless,
avoid surprises and keep the existing behavior);
3. when the User-Agent header is not set, we default to
a `miniooni/0.1.0-dev` user agent, which is probably not
very useful anyway, so we can actually remove it.
Part of https://github.com/ooni/probe/issues/1733 (this diff
has been extracted from https://github.com/ooni/probe-cli/pull/506).
## Description
This PR continues the refactoring of `netx` under the following principles:
1. do not break the rest of the tree and do not engage in extensive tree-wide refactoring yet
2. move under `netxlite` clearly related subpackages (e.g., `iox`, `netxmocks`)
3. move into `internal/netxlite/internal` stuff that is clearly private of `netxlite`
4. hide implementation details in `netxlite` pending new factories
5. refactor `tls` code in `netxlite` to clearly separate `crypto/tls` code from `utls` code
After each commit, I run `go test -short -race ./...` locally. Each individual commit explains what it does. I will squash, but this operation will preserve the original commit titles, so this will give further insight on each step.
## Commits
* refactor: rename netxmocks -> netxlite/mocks
Part of https://github.com/ooni/probe/issues/1591
* refactor: rename quicx -> netxlite/quicx
See https://github.com/ooni/probe/issues/1591
* refactor: rename iox -> netxlite/iox
Regenerate sources and make sure the tests pass.
See https://github.com/ooni/probe/issues/1591.
* refactor(iox): move MockableReader to netxlite/mocks
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): generator is an implementation detail
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): separate tls and utls code
See https://github.com/ooni/probe/issues/1591
* refactor(netxlite): hide most types but keep old names as legacy
With this change we avoid breaking the rest of the tree, but we start
hiding some implementation details a bit. Factories will follow.
See https://github.com/ooni/probe/issues/1591
* fix(all): introduce and use iox.ReadAllContext
This improvement over the ioutil.ReadAll utility returns early
if the context expires. This enables us to unblock stuck code in
case there's censorship confounding the TCP stack.
See https://github.com/ooni/probe/issues/1417.
Compared to the functionality postulated in the above mentioned
issue, I choose to be more generic and separate limiting the
maximum body size (not implemented here) from using the context
to return early when reading a body (or any other reader).
After implementing iox.ReadAllContext, I made sure we always
use it everywhere in the tree instead of ioutil.ReadAll.
This includes many parts of the codebase where in theory we don't
need iox.ReadAllContext. Though, changing all the places makes
checking whether we're not using ioutil.ReadAll where we should
not be using it easy: `git grep` should return no lines.
* Update internal/iox/iox_test.go
* fix(ndt7): treat context errors as non-errors
The rationale is explained by the comment documenting reduceErr.
* Update internal/engine/experiment/ndt7/download.go
This is how I did it:
1. `git clone https://github.com/ooni/probe-engine internal/engine`
2. ```
(cd internal/engine && git describe --tags)
v0.23.0
```
3. `nvim go.mod` (merging `go.mod` with `internal/engine/go.mod`
4. `rm -rf internal/.git internal/engine/go.{mod,sum}`
5. `git add internal/engine`
6. `find . -type f -name \*.go -exec sed -i 's@/ooni/probe-engine@/ooni/probe-cli/v3/internal/engine@g' {} \;`
7. `go build ./...` (passes)
8. `go test -race ./...` (temporary failure on RiseupVPN)
9. `go mod tidy`
10. this commit message
Once this piece of work is done, we can build a new version of `ooniprobe` that
is using `internal/engine` directly. We need to do more work to ensure all the
other functionality in `probe-engine` (e.g. making mobile packages) are still WAI.
Part of https://github.com/ooni/probe/issues/1335
