jokerng

Yet another Docker clone for FreeBSD jails

Why jokerng?

I am yet another poor soul doing DevOps with FreeBSD, dreaming that one day we may have tools similar to Docker and Kubernetes.

Many people in the past came with the idea of implementing or porting Docker to FreeBSD, naming it Jocker. Everybody likes the name because it is catchy: the project uses FreeBSD jails and the Docker/Container movement in Linux is a "joke" for many FreeBSD supporters :)

jokerng will be the best jocker implementation ever and it will not be yet another dead repo in github. I swear!

Objective

Crafting something that provides the minimum functionalities to run disposable jails in FreeBSD.

The concept and philosophy is similar to Docker but without the fancy stuff. I am busy and terrible at coding, that's why I will use off the shelf tools to build the Proof of Concept

Standard FreeBSD packages used:

• Nginx plus pkgng to build a library or catalog.
• zfs snapshots
• ezjail

Setup components

• library to deliver ezjail base and jails with pkgng
• ezjail base (used to deliver a common FreeBSD base to all jails) as a pkg
• Optional: /usr/src as a pkg? ezjail can cause problems with freebsd-update otherwise
• jails exported via zfs snapshot and packaged with pkgng
• some scripts or ansible to automate the management tasks

Package contents

• zfs snapshot
• ezjail config
• ezjail mount point config (for sharing the base plus shared mount points for non-volatile data).
• post install script to load jail (without starting the jail, ez-jail startcrypto is needed to force the start)

Note: The jail doesn't autostart on boot unless we change the config. This must be part of the deployment process when a particular jail is promoted to run live traffic. This way we can have multiple versions for a fast roll back.

PoC

• Vagrant imgage for the library
• Vagrant image for the jailhost
• Packer and Ansible to configure and build the Vagrant images
• Logic to autogenerate the demo packages and the packaged jails distribution.

External links

Creating custom packages in FreeBSD http://lastsummer.de/creating-custom-packages-on-freebsd/