box

README

box -- Containers in a Box

box is a command-lint utility (non-daemon) written in Go for creating Linux containers and sandboxing processes. box is basically a tiny version of docker, it uses neither containerd nor runc. box only implements a sub-set of features you may be used to coming from Docker or similar.

Features

box supports:

• Control Groups for resource restriction (CPU, Memory, Swap, PIDs)
• Namespace for global system resources isolation (Mount, UTS, Network, IPS, PID)
• Union File System for branches to be overlaid in a single coherent file system. (OverlayFS)
• Isolated Networking each container get its own networking and ip address automatically (IPAM)
• Pulling OCI images from the Docker Hub
• Builtin basic Networking and IPAM
• and not much else...

Install

If you have a Go development environment setup with $GOPATH/bin/ in your $PATH the following will just work™ 😀

go get -u git.mills.io/prologic/box

Otherwise you can build from source using git (You still need the Go compiler):

git clone https://git.mills.io/prologic/box.git
cd box
make

Pre-built Binaries

There are pre-built binaries I publish regularly to the Releases page you can download and install. Example:

wget https://git.mills.io/prologic/box/releases/download/0.0.4/box_0.0.4_linux_amd64.tar.gz
tar xvf box_0.0.4_linux_amd64.tar.gz

Running rootless

Since box requires elevated privileges in order to create new namespaces and control groups, it must be run as root or with an effective uid of 0.

You can either run box as root, or you can install the binary with the suid bit set:

chmod u+s box

Usage

# box --help
A tiny tool for managing containers and sandbox processes

Usage:
  box [command]

Available Commands:
  exec        Run a command inside a existing Container.
  help        Help about any command
  images      List local images
  ps          List Containers
  pull        Pulls an OCI compatible image from a registry
  rm          Removes a Container.
  run         Run a command inside a new Container.
  stop        Stops a Container.
  version     Display the version of box and exit

Flags:
  -D, --debug   Enable debug logging
  -h, --help    help for box

Use "box [command] --help" for more information about a command.

Examples

Run /bin/sh in alpine:latest

box run alpine /bin/sh
box run alpine # same as above due to alpine default command

Run /bin/ch -c 'echo "Hwllo World"':

box run alpine -- /bin/sh -c 'echo "Hello World"'

NOTE: The -- is important here as this acts as the "flag terminator" for the box CLI and the run sub-command and allows you to then use command-line options that are passed to your images' entrypoint.

Networking

IP Address Management (IPAM)

Currently box has a builtin IPAM (IP Address Management) that has a hard coded subnet of 172.30.0.0/16. A box0 bridge (switch) is setup for all containers (automatically) and containers are put into their own isolated Network Namespace and assigned an IP Address out of this subnet automatically (without requiring DHCP).

Currently there is no support for using a different subnet or assigning static IP Addresses to containers at this time.

External Networking and Port Mapping

box uses nftables to create and manipulate NAT rules to allow containers access to external networks (MASQUERADE) and mapping ports from the host to the container (DNAT).

DNS Resolvers

box injects the host's /etc/resolv.conf into a newly formed container so as long as DNS Resolution works on your host, it will work inside containers too.

Notes

box is/does NOT:

• designed to be minimal and lightweight.
• designed to be used in critical production workloads (yet).
• have any orchestrator(s) for managing services.
• have any multi-host or clustering support of any kind.
• have any support for volumes besides bind-mount(s) from the host
• have any other features you'd expect from Docker, Docker Swarm or Kubernetes.

License

box is licensed under the MIT License.