conbox

conbox is a Go implementation of unix-like utilities as single static executable intended for small container images.

• Install
• Usage
  • Available applets
  • Basename usage
  • Subcommand usage
  • Shell usage
• Adding new applet
• Docker
  • Run in docker
  • Docker recipes
• Related work
  • Go Projects
  • Non-Go projects

Created by gh-md-toc

Install

git clone https://github.com/udhos/conbox ;# clone outside of GOPATH
cd conbox
GO111MODULE=on go install ./conbox

Usage

Available applets

List available applets:

$ conbox
conbox: version 0.0 runtime go1.12.4 GOMAXPROC=1 OS=linux ARCH=amd64

usage: conbox APPLET [ARG]... : run APPLET
       conbox -h              : show command-line help
       conbox -l              : list applets

conbox: registered applets:
cat echo ls mkdir printenv pwd rm rmdir shell which

See all implemented applets here:

https://github.com/udhos/conbox/tree/master/applets

Basename usage

You can create a symbolic link for a supported applet pointing to 'conbox':

ln -s ~/go/bin/conbox ~/bin/cat
~/bin/cat /etc/passwd

Subcommand usage

Pass applet name as subcommand to 'conbox':

conbox cat /etc/passwd

Shell usage

All applets are also directly available from within conbox shell:

$ conbox shell
conbox: version 0.0 runtime go1.12.4 GOMAXPROC=1 OS=linux ARCH=amd64

welcome to conbox shell.
this tiny shell is very limited in features.
however you can run external programs normally.
some hints:
       - use 'conbox' to see all applets available as shell commands.
       - use 'help' to list shell built-in commands.
       - 'exit' terminates the shell.

shell built-in commands:
builtin cd exit help

conbox shell$

Adding new applet

1. Create a new package for the applet under directory 'applets'. The package must export the function Run() as show in example below.

$ more applets/myapp/run.go
package myapp // put applet myapp in package myapp

import (
        "fmt"

        "github.com/udhos/conbox/common"
)

// Run executes the applet.
func Run(tab map[string]common.AppletFunc, args []string) int {

        fmt.Println("myapp: hello")

        return 0 // exit status
}

2. In file 'conbox/applets.go', import the applet package and include its Run() function in the applet table:

$ more conbox/applets.go
package main

import (
	// (...)
        "github.com/udhos/conbox/applets/myapp" // <-- import the applet package
	// (...)
)

func loadApplets() map[string]common.AppletFunc {
        tab := map[string]common.AppletFunc{
		// (...)
                "myapp": myapp.Run, // <-- point applet name to its Run() function
		// (...)
        }
        return tab
}

3. Rebuild conbox and test the new applet:

$ go install ./conbox
$ conbox myapp
myapp: hello

Docker

Get 'conbox' as docker image udhos/conbox:latest from:

https://hub.docker.com/r/udhos/conbox

Run in docker

Run applet:

docker run --rm udhos/conbox:latest cat /etc/passwd

Run interactive shell:

docker run --rm -ti udhos/conbox:latest shell

Docker recipes

Build docker image:

./docker/build.sh

Tag image:

docker tag udhos/conbox udhos/conbox:latest

Push image:

docker login
docker push udhos/conbox:latest

Related work

Go Projects

• https://github.com/u-root/u-root

Unfortunately these projects seem inactive:

• https://github.com/surma/gobox
• https://github.com/laher/someutils
• https://github.com/shirou/toybox
• https://github.com/u35s/busybox
• https://github.com/ericlagergren/go-coreutils

Non-Go projects

• https://www.busybox.net/
• http://landley.net/toybox/