* refactor: move tracex outside of engine/netx
Consistently with https://github.com/ooni/probe/issues/2121 and
https://github.com/ooni/probe/issues/2115, we can now move tracex
outside of engine/netx. The main reason why this makes sense now
is that the package is now changed significantly from the one
that we imported from ooni/probe-engine.
We have improved its implementation, which had not been touched
significantly for quite some time, and converted it to unit
testing. I will document tomorrow some extra work I'd like to
do with this package but likely could not do $soon.
* go fmt
* regen tutorials
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
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
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 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
