5 ms·

Fang, the CLI Starter Kit

147 points by bewuethr 1y ago

johnisgood 1y ago
I just ran across "gum"[1] from charmbracelet which I intend to use! I just want to replace dialog. I came across whiptail, too, but gum seems nicer. They have a TUI framework, too, among a lot of other related things. Some of their projects are Go libraries, some are a CLI tool, such as gum. [1] https://github.com/charmbracelet/gum https://github.com/charmbracelet/gum
- nodesocket 1y ago
  Gum looks awesome. Gonna keep it in-mind next time I need to write a shell CLI.
csomar 1y ago
I’ve been maintaining rust-starter[!] for quite sometime now. It is kind of the equivalent of fang but for Rust. It uses Clap which is the equivalent of Cobra; though I don’t think Clap has the same kind of fancy output? Throughout these years, I have found that cross-compiling is the most challenging part of creating a CLI. When you are building a web back-end, you control the execution environment (usually linux). For CLIs, your users could be on Linux, macOS or Windows. You need to get three x2 binaries (so a total of 6) to have a fair coverage. I’ve tried cross, but for Windows and macOS you need licenses. There is no straightforward way to give your users Docker images and have them running in a few commands. You can compile on GitHub action machines, but that’s a very slow feedback loop. I wonder if things are better in Go land. !: https://github.com/rust-starter/rust-starter https://github.com/rust-starter/rust-starter
- christianrocha 1y ago
  I feel your pain. That said, cross compiling from Go is pretty trivial, as long as everything is pure Go, which it most often is. That’s one if the reasons we invested in jt. (Hello from Charm! I’m one of the authors of this library.)
- neomantra 1y ago
  Golang itself bundles a toolchain and can cross compile to a many target OSes and architectures. I use Goreleaser [1] to create GitHub releases, Homebrew packages, Docker images, and Linux packages. Goreleaser Pro can also create MSI packages. ETA since I just saw Christian chime in: the Goreleaser author works at Charm.sh =) [1] https://goreleaser.com https://goreleaser.com
  - deleted 1y ago
    [deleted]
  - christianrocha 1y ago
    GoReleaser is indeed an awesome tool and we use it for every applicable project. And actually Carlos, who builds GoReleaser, is the true author of Fang and took it from concept to execution.
- mootoday 1y ago
  This is great, lots I learned by looking at your code and the dependencies you use! I started a similar thing, although not as feature-rich as yours. My goal was to follow CLI best practices and add all the boilerplate one needs to build a Rust CLI. https://github.com/mootoday/cli-template https://github.com/mootoday/cli-template
- threemux 1y ago
  Wow TIL cross compilation is a bit of a pain in Rust. I assumed it was as easy as Go. I can confirm as long as you're using pure Go (no cgo), it's as easy as setting $GOOS and $GOARCH appropriately.
  - paulddraper 1y ago
    The difficulty is due to Rust dynamically linking and Go statically linking. The former requires the system libs. That said, I am unfamiliar with any licensing for Windows builds. MacOS has some niche (usually discarded) technicalities like you can only use the SDK on Apple hardware.
    - threemux 1y ago
      I think that's a reference to the use of Docker in the "cross" tool that makes cross compilation easier but I'm not certain
- rmac 1y ago
  I looked into how rust does does it for rustup, and they have a pretty amazing set of gh actions to build for their architectures, I can't find the GH link now tho for speed you can look for vendors like https://depot.dev/ https://depot.dev/
- masfuerte 1y ago
  I configure github actions to build each version in its natural habitat. Though my motivation for this was getting the builds off my machine. I didn't want to be shipping binaries I had built locally.
RSHEPP 1y ago
Just re-wrote an internal CLI to urfave from custom, but having issues with v3 autocomplete scripts. Might just take the time to switch over to cobra and use this.
- syvolt 1y ago
  I think kong[1] is better than both options although cobra is by far the most popular. Might be worth a look. Definitely won't look as pretty as the parent project though but I prefer kong in terms of the actual code you need to write. [1] https://github.com/alecthomas/kong https://github.com/alecthomas/kong
  - bbkane 1y ago
    OP said they want completion support, which Kong doesn't include. https://github.com/jotaen/kong-completion https://github.com/jotaen/kong-completion exists, but the last commit was 2 years ago.
jmsdnns 1y ago
This is awesome! Love the work the charm bracelet team is doing.
- christianrocha 1y ago
  Thank you for the very kind words. Hello from Charm!
jonpalmisc 1y ago
Stubborn complaint (and maybe a hot take): I dislike CLIs that try to be overly pretty. I don't receive any tangible benefit as the user from the "fancy" (their words) help output. I'd much rather simple plain text output that looks like all the other tools I already use.
- assbuttbuttass 1y ago
  agreed, plain text is more scriptable too. Let me pipe it into awk!
  - caarlos0 1y ago
    If you do it right, you can output plain text when stdout is not a tty - which is something fang does, fwiw :)
    - arp242 1y ago
      It still tries to put the terminal in raw mode or something. "cmd | less" doesn't work and requires "stty sane". I didn't investigate, but FYI.
  - kitd 1y ago
    A lot of the fancy CLIs I use have a `--json` option that gives the user the chance to pipe output to eg jq and process it there. I find that a good alternative to running stuff through cut, sed or awk before processing.
- arp242 1y ago
  Alignment (and maybe bold text for some things) is all you need in >95% of cases, IMHO. One of the downsides of a lot of these tools is that's exactly what they don't do well: many things don't align or wrap nicely. For example, here's a comparison of this fang library vs one where I just raw-dogged the usage text: https://imgur.com/a/QWh9TLD https://imgur.com/a/QWh9TLD – the nice alignment does a lot more than colours. Especially for larger programs with a bunch of flags it can be such a pain. For example from an otherwise quite nice tool: https://imgur.com/a/RELL9Gk https://imgur.com/a/RELL9Gk – you just completely lose any "overview". I did spend some time on some better tooling to improve all of this, because manually writing these isn't super-fun either, but not so straight-forward to do well (or at least: not in a way that I like).
bbkane 1y ago
It would be really cool if Fang could generate a TUI form for your app with https://github.com/charmbracelet/huh https://github.com/charmbracelet/huh (by the same org). Is something like that on the roadmap? Similar work: https://github.com/chriskiehl/Gooey https://github.com/chriskiehl/Gooey and https://github.com/Sorcerio/Argparse-Interface https://github.com/Sorcerio/Argparse-Interface I've wanted to do TUI form generation for my own CLI framework since 2023 ( https://github.com/bbkane/warg/issues/71 https://github.com/bbkane/warg/issues/71 ), but I still haven't gotten around to it
Cthulhu_ 1y ago
That's pretty neat, although it's little more than a coloring wrapper around Cobra. That said, I wrote a small tool for a hackathon and just dropped this in for a bit of whimsy.
aranw 1y ago
It's probably more accurate to say it's a Go Cobra CLI Starter Kit rather just a generic CLI Starter kit. I personally find Cobra bit OTT and bloated and try to avoid it where I can but this could be a nice starter point for my own similar library to suit my needs

147 points by bewuethr 1y ago

I just ran across "gum"[1] from charmbracelet which I intend to use! I just want to replace dialog. I came across whiptail, too, but gum seems nicer. They have a TUI framework, too, among a lot of other related things. Some of their projects are Go libraries, some are a CLI tool, such as gum. [1] https://github.com/charmbracelet/gum https://github.com/charmbracelet/gum

nodesocket 1y ago
Gum looks awesome. Gonna keep it in-mind next time I need to write a shell CLI.

csomar 1y ago

I’ve been maintaining rust-starter[!] for quite sometime now. It is kind of the equivalent of fang but for Rust. It uses Clap which is the equivalent of Cobra; though I don’t think Clap has the same kind of fancy output? Throughout these years, I have found that cross-compiling is the most challenging part of creating a CLI. When you are building a web back-end, you control the execution environment (usually linux). For CLIs, your users could be on Linux, macOS or Windows. You need to get three x2 binaries (so a total of 6) to have a fair coverage. I’ve tried cross, but for Windows and macOS you need licenses. There is no straightforward way to give your users Docker images and have them running in a few commands. You can compile on GitHub action machines, but that’s a very slow feedback loop. I wonder if things are better in Go land. !: https://github.com/rust-starter/rust-starter https://github.com/rust-starter/rust-starter

christianrocha 1y ago
I feel your pain. That said, cross compiling from Go is pretty trivial, as long as everything is pure Go, which it most often is. That’s one if the reasons we invested in jt. (Hello from Charm! I’m one of the authors of this library.)
neomantra 1y ago
Golang itself bundles a toolchain and can cross compile to a many target OSes and architectures. I use Goreleaser [1] to create GitHub releases, Homebrew packages, Docker images, and Linux packages. Goreleaser Pro can also create MSI packages. ETA since I just saw Christian chime in: the Goreleaser author works at Charm.sh =) [1] https://goreleaser.com https://goreleaser.com
- deleted 1y ago
  [deleted]
- christianrocha 1y ago
  GoReleaser is indeed an awesome tool and we use it for every applicable project. And actually Carlos, who builds GoReleaser, is the true author of Fang and took it from concept to execution.
mootoday 1y ago
This is great, lots I learned by looking at your code and the dependencies you use! I started a similar thing, although not as feature-rich as yours. My goal was to follow CLI best practices and add all the boilerplate one needs to build a Rust CLI. https://github.com/mootoday/cli-template https://github.com/mootoday/cli-template
threemux 1y ago
Wow TIL cross compilation is a bit of a pain in Rust. I assumed it was as easy as Go. I can confirm as long as you're using pure Go (no cgo), it's as easy as setting $GOOS and $GOARCH appropriately.
- paulddraper 1y ago
  The difficulty is due to Rust dynamically linking and Go statically linking. The former requires the system libs. That said, I am unfamiliar with any licensing for Windows builds. MacOS has some niche (usually discarded) technicalities like you can only use the SDK on Apple hardware.
  - threemux 1y ago
    I think that's a reference to the use of Docker in the "cross" tool that makes cross compilation easier but I'm not certain
rmac 1y ago
I looked into how rust does does it for rustup, and they have a pretty amazing set of gh actions to build for their architectures, I can't find the GH link now tho for speed you can look for vendors like https://depot.dev/ https://depot.dev/
masfuerte 1y ago
I configure github actions to build each version in its natural habitat. Though my motivation for this was getting the builds off my machine. I didn't want to be shipping binaries I had built locally.

RSHEPP 1y ago

Just re-wrote an internal CLI to urfave from custom, but having issues with v3 autocomplete scripts. Might just take the time to switch over to cobra and use this.

syvolt 1y ago
I think kong[1] is better than both options although cobra is by far the most popular. Might be worth a look. Definitely won't look as pretty as the parent project though but I prefer kong in terms of the actual code you need to write. [1] https://github.com/alecthomas/kong https://github.com/alecthomas/kong
- bbkane 1y ago
  OP said they want completion support, which Kong doesn't include. https://github.com/jotaen/kong-completion https://github.com/jotaen/kong-completion exists, but the last commit was 2 years ago.

jmsdnns 1y ago

This is awesome! Love the work the charm bracelet team is doing.

christianrocha 1y ago
Thank you for the very kind words. Hello from Charm!

jonpalmisc 1y ago

Stubborn complaint (and maybe a hot take): I dislike CLIs that try to be overly pretty. I don't receive any tangible benefit as the user from the "fancy" (their words) help output. I'd much rather simple plain text output that looks like all the other tools I already use.

assbuttbuttass 1y ago
agreed, plain text is more scriptable too. Let me pipe it into awk!
- caarlos0 1y ago
  If you do it right, you can output plain text when stdout is not a tty - which is something fang does, fwiw :)
  - arp242 1y ago
    It still tries to put the terminal in raw mode or something. "cmd | less" doesn't work and requires "stty sane". I didn't investigate, but FYI.
- kitd 1y ago
  A lot of the fancy CLIs I use have a `--json` option that gives the user the chance to pipe output to eg jq and process it there. I find that a good alternative to running stuff through cut, sed or awk before processing.
arp242 1y ago
Alignment (and maybe bold text for some things) is all you need in >95% of cases, IMHO. One of the downsides of a lot of these tools is that's exactly what they don't do well: many things don't align or wrap nicely. For example, here's a comparison of this fang library vs one where I just raw-dogged the usage text: https://imgur.com/a/QWh9TLD https://imgur.com/a/QWh9TLD – the nice alignment does a lot more than colours. Especially for larger programs with a bunch of flags it can be such a pain. For example from an otherwise quite nice tool: https://imgur.com/a/RELL9Gk https://imgur.com/a/RELL9Gk – you just completely lose any "overview". I did spend some time on some better tooling to improve all of this, because manually writing these isn't super-fun either, but not so straight-forward to do well (or at least: not in a way that I like).

bbkane 1y ago

It would be really cool if Fang could generate a TUI form for your app with https://github.com/charmbracelet/huh https://github.com/charmbracelet/huh (by the same org). Is something like that on the roadmap? Similar work: https://github.com/chriskiehl/Gooey https://github.com/chriskiehl/Gooey and https://github.com/Sorcerio/Argparse-Interface https://github.com/Sorcerio/Argparse-Interface I've wanted to do TUI form generation for my own CLI framework since 2023 ( https://github.com/bbkane/warg/issues/71 https://github.com/bbkane/warg/issues/71 ), but I still haven't gotten around to it

Cthulhu_ 1y ago

That's pretty neat, although it's little more than a coloring wrapper around Cobra. That said, I wrote a small tool for a hackathon and just dropped this in for a bit of whimsy.

aranw 1y ago

It's probably more accurate to say it's a Go Cobra CLI Starter Kit rather just a generic CLI Starter kit. I personally find Cobra bit OTT and bloated and try to avoid it where I can but this could be a nice starter point for my own similar library to suit my needs