cuckoo

A crontab visualizer made in Go with Raylib bindings.

Initially made for learning purposes, finished out of love <3 (or masochism).

Index

• Motivation
• Install & use
• Dependencies
• Build
• Roadmap
  • CGO_ENABLED=0
  • WASM

Motivation

Imagine a process orchestrator (Airflow, Celery, etc.) that coordinates over 200 processes. Each process has a cron that defines when it will be executed.

Now, think about how you would decide the cron for your new process. This is important so your new cron doesn't collide with heavy processes or workload peaks, which would create overhead that could be better distributed.

It's hard if can't visualize the data, right? That's where cuckoo comes in.

cuckoo lets you visualize crons as coordinates on a grid to:

• Get insights about your crons with just a glance.
• Know the next free spot where you can place a new cron.
• Identify periods where there is a work overload.

Install & use

To install cuckoo:

go install github.com/kerudev/cuckoo@latest

Takes a JSON file with the following structure:

{
  "process_1": "*/5 * * * *",
  "process_2": "0 */2 * * *",
  "process_3": "15 3 * * *",
  // ...
}

Or a CSV file with two columns (header names are just a convention, but mind the colons!):

name,cron
process_1,"*/5 * * * *"
process_2,"0 */2 * * *"
process_3,"15 3 * * *"
# ...

To run cuckoo:

cuckoo                      # Runs from the current directory
cuckoo -path path/to/data   # Runs from a directory / loads and parses a file

Dependencies

cuckoo's dependencies:

• raylib-go: Go bindings for raylib & raygui.

dev dependencies:

• air: hot module reloading for Go.

Build

When running go build or go run, you may want to pass the tags argument. This tells the bindings how to handle windows, and keyboard and mouse events.

Example:

go run -tags x11 . -path ...

I usually compile with the noaudio tag to save space, as there are no audio involved in cuckoo:

go build -tags x11
du -sh cuckoo
7.8M    cuckoo

go build -tags noaudio,x11
du -sh cuckoo
6.5M    cuckoo

• List of tags: https://github.com/gen2brain/raylib-go/blob/master/README.md#build-tags
• Related discussion: gen2brain/raylib-go#554

Roadmap

CGO_ENABLED=0

Although cuckoo is a really small program, I feel like it spends too much time on the CPU, probably due to not being able to compile without cgo.

The debug module has a DebugServer() that I use to measure performance.

I run cuckoo on one shell and this command on other shell:

go tool pprof http://localhost:6060/debug/pprof/profile?seconds=10

 flat  flat%   sum%        cum   cum%
7.96s 80.24% 80.24%      9.51s 95.87%  runtime.cgocall
0.29s  2.92% 83.17%      0.49s  4.94%  runtime.casgstatus
0.28s  2.82% 85.99%      0.76s  7.66%  runtime.reentersyscall

Seems like 95% of the time is spent on the CPU doing cgo stuff.

Right now, cuckoo can't compile with CGO_ENABLED=0 because raygui doesn't support it, but I plan for that to change.

WASM

This project is currently being developed just for desktop. A WASM port is in the works but not ready yet, as the project that ports raylib to WASM doesn't support raygui yet (see BrownNPC/Raylib-Go-Wasm #10).

Caution

These notes are subject to change, as they describe the current way of using the raygui bindings, which are under development on other project.

Complete guide: https://github.com/BrownNPC/Raylib-Go-Wasm/blob/master/README.md

To compile cuckoo to WASM:

1. Clone or create a symlink to the WASM bindings repository:

git clone https://github.com/BrownNPC/Raylib-Go-Wasm.git

ln -s path/to/Raylib-Go-Wasm/ Raylib-Go-Wasm  # I do this while developing the bindings

2. Checkout to the raygui branch.

3. Paste this into go.mod and run go mod tidy:

replace (
	github.com/gen2brain/raylib-go/raygui => ./Raylib-Go-Wasm/raygui
	github.com/gen2brain/raylib-go/raylib => ./Raylib-Go-Wasm/raylib
	github.com/BrownNPC/Raylib-Go-Wasm/wasm-runtime => ./Raylib-Go-Wasm/wasm-runtime
)

4. WASM doesn't support Raylib's WindowShouldClose(), so you need to change this:

for !rl.WindowShouldClose() { ... }

To this:

var update = func() { ... }

rl.SetMainLoop(update)

5. You might lots of errors in the code, but they are normal. Compile with:

GOOS=js GOARCH=wasm go build -o ./Raylib-Go-Wasm/index/main.wasm .

6. Run the server of your choice:

• On Python: cd Raylib-Go-Wasm/index && python -m http.server
• On Go: go build ./Raylib-Go-Wasm/server/server.go then ./server