mirror of
https://github.com/wezm/wezm.net.git
synced 2024-12-19 02:39:54 +00:00
117 lines
5.5 KiB
Markdown
117 lines
5.5 KiB
Markdown
As a learning and practice exercise I built a [crate] for interacting with the
|
|
[Lobsters](https://lobste.rs/) programming community website. It's built on the
|
|
asynchronous Rust ecosystem. To demonstrate the crate I also built a terminal
|
|
user interface (TUI).
|
|
|
|
<figure>
|
|
<img style="border: 2px solid black" src="/images/2019/lobsters-tui.png" alt="Screenshot of Lobsters TUI" />
|
|
<figcaption>A screenshot of the TUI in <a href="https://github.com/jwilm/alacritty">Alacritty</a></figcaption>
|
|
</figure>
|
|
|
|
## Try It
|
|
|
|
[](https://crates.io/crates/lobsters)
|
|
|
|
Pre-built binaries with no runtime dependencies are available for:
|
|
|
|
- FreeBSD 12 amd64
|
|
- Linux armv6 (Raspberry Pi)
|
|
- Linux x86_64
|
|
- MacOS
|
|
- NetBSD 8 amd64
|
|
- OpenBSD 6.5 amd64
|
|
|
|
<a class="action-button action-button-ghost" href="https://git.sr.ht/~wezm/lobsters#download">Downloads</a>
|
|
<a class="action-button action-button-ghost" href="https://git.sr.ht/~wezm/lobsters">Source Code</a>
|
|
|
|
|
|
The TUI uses the following key bindings:
|
|
|
|
* `j` or `↓` — Move cursor down
|
|
* `k` or `↑` — Move cursor up
|
|
* `h` or `←` — Scroll view left
|
|
* `l` or `→` — Scroll view right
|
|
* `Enter` — Open story URL in browser
|
|
* `c` — Open story comments in browser
|
|
* `q` or `Esc` — Quit
|
|
|
|
As mentioned in the introduction the motivation for starting the client was to
|
|
practice using the async Rust ecosystem and it kind of spiralled from there.
|
|
The resulting TUI is functional but not especially useful, since it just opens
|
|
links in your browser. I can imagine it being slightly more useful if you could
|
|
also view and reply to comments without leaving the UI.
|
|
|
|
## Building It
|
|
|
|
The client proved to be an interesting challenge, mostly because Lobsters
|
|
doesn't have a full API. This meant I had to learn how to set up and use a
|
|
cookie jar along side [reqwest] in order to make authenticated requests.
|
|
Logging in requires supplying a cross-site request forgery token, which Rails
|
|
uses to prevent CSRF attacks. To handle this I need to first fetch the login
|
|
page, note the token, then POST to the login endpoint. I could have tried to
|
|
extract the token from the markup with a regex or substring matching but
|
|
instead used [kuchiki] to parse the HTML and then match on the `meta` element
|
|
in the `head`.
|
|
|
|
Once I added support for writing with the client (posting comments), not just
|
|
reading, I thought I best not test against the real site. Fortunately the site's
|
|
code is open source. I took this as an opportunity to use [my new-found Docker
|
|
knowledge][alpine-docker] and run it with Docker Compose. That turned out
|
|
pretty easy since I was able to base it on one of the Dockerfiles for a Rails
|
|
app I run. If you're curious the [Alpine Linux] based `Dockerfile` and
|
|
`docker-compose.yml` can be viewed in [this
|
|
paste](https://paste.sr.ht/%7Ewezm/6da6b05677f80069b166433b19ef2209176f036f).
|
|
|
|
After I had the basics of the client worked out I thought it would be neat to
|
|
fetch the front page stories and render them in the terminal in a style similar
|
|
to the site itself. I initially did this with [ansi_term]. It looked good but
|
|
lacked interactivity so I looked into ways to build a TUI along the lines of
|
|
[tig]. I built it several times with different crates, switching each time I
|
|
hit a limitation. I tried:
|
|
|
|
* [easycurses], which lived up to it's name and produced a working result
|
|
quickly. I'd recommend this if your needs aren't too fancy, however I needed
|
|
more control than it provided.
|
|
* [pancurses] didn't seem to be able to use colors outside the core 16 from
|
|
ncurses.
|
|
|
|
Finally I ended up going a bit lower-level and used [termion]. It does
|
|
everything itself but at the same time you lose the conveniences ncurses
|
|
provides. It also doesn't support Windows, so my plans of supporting that were
|
|
thwarted. Some time after I had the `termion` version working I revisited
|
|
[tui-rs], which I had initially dismissed as unsuitable for my task. In
|
|
hindsight it would probably have been perfect, but we're here now.
|
|
|
|
In addition to async and TUI I also learned more about:
|
|
|
|
- Building a robust and hopefully user friendly command line tool.
|
|
- Documenting a library.
|
|
- Publishing crates.
|
|
- Dockerising a Rails app that uses MySQL.
|
|
- How to build and publish pre-built binaries for many platforms.
|
|
- How to accept a password in the terminal without echoing it.
|
|
- Setting up multi-platform [CI builds on Sourcehut][builds].
|
|
|
|
Whilst the library and UI aren't especially useful the exercise was worth it. I got
|
|
to practice a bunch of things and learn some new ones at the same time.
|
|
|
|
<img src="/images/lobsters.png" alt="" width="16" class="lobsters"> [Comments on Lobsters](https://lobste.rs/s/nono6k/what_i_learnt_building_lobsters_tui_rust)
|
|
|
|
<div class="seperator"><hr class="left">✦<hr class="right"></div>
|
|
|
|
Previous Post: [Cross Compiling Rust for FreeBSD With Docker](/technical/2019/03/cross-compile-freebsd-rust-binary-with-docker/)
|
|
Next Post: [An Illustrated Guide to Useful Command Line Tools](/technical/2019/10/useful-command-line-tools/)
|
|
|
|
[repo]: https://git.sr.ht/~wezm/lobsters
|
|
[ansi_term]: https://crates.io/crates/ansi_term
|
|
[tig]: https://jonas.github.io/tig/
|
|
[pancurses]: https://crates.io/crates/pancurses
|
|
[tui-rs]: https://crates.io/crates/tui
|
|
[termion]: https://crates.io/crates/termion
|
|
[builds]: https://man.sr.ht/builds.sr.ht/
|
|
[reqwest]: https://crates.io/crates/reqwest
|
|
[kuchiki]: https://crates.io/crates/kuchiki
|
|
[alpine-docker]: /technical/2019/02/alpine-linux-docker-infrastructure/
|
|
[easycurses]: https://crates.io/crates/easycurses
|
|
[Alpine Linux]: https://alpinelinux.org/
|
|
[crate]: https://crates.io/crates/lobsters
|