Add lobsters post

content/technical/2019/03/cross-compile-freebsd-rust-binary-with-docker.md

@@ -134,8 +134,8 @@ Once again, the code is at: <https://github.com/wezm/freebsd-cross-build>.
 
 <div class="seperator"><hr class="left">✦<hr class="right"></div>
 
-Previous Post: [My First 3 Weeks of Professional Rust](/technical/2019/03/first-3-weeks-of-professional-rust/)
+Previous Post: [My First 3 Weeks of Professional Rust](/technical/2019/03/first-3-weeks-of-professional-rust/)  
-
+Next Post: [What I Learnt Building a Lobsters TUI in Rust](/technical/2019/04/lobsters-tui/)
 
 [freebsd-cross-upstream]: https://github.com/sandvine/freebsd-cross-build
 [user namespaces]: https://docs.docker.com/engine/security/userns-remap/

content/technical/2019/04/lobsters-tui.md

@@ -0,0 +1,117 @@
+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
+
+[![crates.io](https://img.shields.io/crates/v/lobsters.svg)](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"> [Discuss on Lobsters](https://lobste.rs/s/7op1vm/my_first_3_weeks_professional_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:  -->
+
+[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

content/technical/2019/04/lobsters-tui.yaml

@@ -0,0 +1,14 @@
+---
+title: What I Learnt Building a Lobsters TUI in Rust
+extra: As a learning and practice exercise I built a crate and TUI for interacting with the Lobsters programming community website.
+kind: article
+section: technical
+created_at: 2019-04-25 16:00:00.000000000 +11:00
+#updated_at: 2019-03-30T10:02:56+11:00
+keywords:
+  - rust
+  - lobsters
+  - async
+  - tokio
+  - tui
+short_url: