Rather than passing functions to construct complex objects such
as Dialer and QUICDialer, pass interface implementations.
Ensure that a nil implementation does not cause harm.
Make Saver implement the correct interface either directly or
indirectly. We need to implement the correct interface indirectly
for TCP conns (or connected UDP sockets) because we have two
distinct use cases inside netx: observing just the connect event
and observing just the I/O events.
With this change, the construction of composed Dialers and
QUICDialers is greatly simplified and more obvious.
Part of https://github.com/ooni/probe/issues/2121
This diff creates a new package under netx called tracex that
contains everything we need to perform measurements using events
tracing and postprocessing (which is the technique with which
we implement most network experiments).
The general idea here is to (1) create a unique package out of
all of these packages; (2) clean up the code a bit (improve tests,
docs, apply more recent code patterns); (3) move the resulting
code as a toplevel package inside of internal.
Once this is done, netx can be further refactored to avoid
subpackages and we can search for more code to salvage/refactor.
See https://github.com/ooni/probe/issues/2121
This diff modifies the construction of a dialer to allow one
to insert custom dialer wrappers into the dialers chain.
The point of the chain in which we allow custom wrappers is the
optimal one for connect, read, and write measurements.
This new design is better than the previous netx design since
we don't need to construct the whole chain manually now.
The work in this diff is part of the effort to make engine/netx
just a tiny wrapper around netxlite.
See https://github.com/ooni/probe/issues/2121.
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?).
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.)
## 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
I discovered which transport were used by apitool and made sure he gets the same transports now. While there, I discovered an issue with ooni/oohttp that has been fixed with cba9b1ce5e.
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
Like we did before for the resolver, a dialer should propagate the
request to close idle connections to underlying types.
See https://github.com/ooni/probe/issues/1591
We would like to refactor the code so that a DoH resolver owns the
connections of its underlying HTTP client.
To do that, we need first to incorporate CloseIdleConnections
into the Resolver model. Then, we need to add the same function
to all netxlite types that wrap a Resolver type.
At the same time, we want the rest of the code for now to continue
with the simpler definition of a Resolver, now called ResolverLegacy.
We will eventually propagate this change to the rest of the tree
and simplify the way in which we manage Resolvers.
To make this possible, we introduce a new factory function that
adapts a ResolverLegacy to become a Resolver.
See https://github.com/ooni/probe/issues/1591.
What do I mean by pivoting? Netx is currently organized by row:
```
| dialer | quicdialer | resolver | ...
saving | | | | ...
errorwrapping | | | | ...
logging | | | | ...
mocking/sys | | | | ...
```
Every row needs to implement saving, errorwrapping, logging, mocking (or
adapting to the system or to some underlying library).
This causes cross package dependencies and, in turn, complexity. For
example, we need the `trace` package for supporting saving.
And `dialer`, `quickdialer`, et al. need to depend on such a package.
The same goes for errorwrapping.
This arrangement further complicates testing. For example, I am
currently working on https://github.com/ooni/probe/issues/1505 and
I realize it need to repeat integration tests in multiple places.
Let's say instead we pivot the above matrix as follows:
```
| saving | errorwrapping | logging | ...
dialer | | | | ...
quicdialer | | | | ...
logging | | | | ...
mocking/sys | | | | ...
...
```
In this way, now every row contains everything related to a specific
action to perform. We can now share code without relying on extra
support packages. What's more, we can write tests and, judding from
the way in which things are made, it seems we only need integration
testing in `errorwrapping` because it's where data quality matters
whereas, in all other cases, unit testing is fine.
I am going, therefore, to proceed with these changes and "pivot"
`netx`. Hopefully, it won't be too painful.
* refactor(netx/dialer): hide implementation complexity
This follows the blueprint of `module.Config` and `nodule.New`
described at https://github.com/ooni/probe/issues/1591.
* fix: ndt7 bug where we were not using the right resolver
* fix(legacy/netx): clarify irrelevant implementation change
* fix: improve comments
* fix(hhfm): do not use dialer.New b/c it breaks it
Unclear to me why this is happening. Still, improve upon the
previous situation by adding a timeout.
It does not seem a priority to look into this issue now.
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
