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WARNING: This software is new, experimental, and under heavy development. The documentation is lacking, if any. There are almost no tests. The CLI commands, on-disk formats, APIs, and source code layout can change in any moment. Do not trust it. Use it at your own risk.

You have been warned

Jetpack

Jetpack is an experimental and incomplete implementation of the App Container Specification for FreeBSD. It uses jails as isolation mechanism, and ZFS for layered storage.

This document uses some language used in Rocket, the reference implementation of the App Container Specification. While the documentation will be expanded in the future, currently you need to be familiar at least with Rocket's README to understand everything.

Compatibility

Jetpack is developed and tested on an up-to-date FreeBSD 10.1 system, and compiled with Go 1.4. Earlier FreeBSD releases are not supported.

Getting Started

VM with vagrant

To spin up a pre configured FreeBSD VM with Vagrant

Make sure you have ansible installed on the host system.

Then boot and provision the VM by running $ vagrant up in the root directory of this repository. Run $ vagrant ssh to ssh into the machine. The code is mounted under /vagrant.

Configuring the system

First, build Jetpack and install it (see the INSTALL.md document for installation instructions).

You will obviously need a ZFS pool for Jetpack's datasets. By default, Jetpack will create a zroot/jetpack dataset and mount it at /var/jetpack. If your zpool is not named zroot, or if you prefer different locations, these defaults can be modified in the jetpack.conf file.

You will need a user and group to own the runtime status files and avoid running the metadata service as root. If you stay with default settings, the username and group should be _jetpack:

pw useradd _jetpack -d /var/jetpack -s /usr/sbin/nologin

Note: If you are upgrading from an earlier revision of Jetpack, you will need to change ownership of files and directories: chgrp _jetpack /var/jetpack/pods/* /var/jetpack/images/* /var/jetpack/*/*/manifest && chmod 0440 /var/jetpack/*/*/manifest

You will also need a network interface that the jails will use, and this interface should have Internet access. By default, Jetpack uses lo1, but this can be changed in the jetpack.conf file. To create the interface, run the following command as root:

ifconfig lo1 create inet 172.23.0.1/16

To have the lo1 interface created at boot time, add the following lines to /etc/rc.conf:

cloned_interfaces="lo1"
ipv4_addrs_lo1="172.23.0.1/16"

The main IP address of the interface will be used as the host address. Remaining addresses within its IP range (in this case, 172.23.0.2 to 172.23.255.254) will be assigned to the pods. IPv6 is currently not supported.

The simplest way to provide internet access to the jails is to NAT the loopback interface. A proper snippet of PF firewall configuration would be:

set skip on lo1
nat pass on $ext_if from lo1:network to any -> $ext_if

where $ext_if is your external network interface. A more sopihisticated setup can be desired to limit pods' connectivity. In the long run, Jetpack will probably manage its own pf anchor.

You will need to create a jetpack.conf file (by default, /usr/local/etc/jetpack.conf) with at least following settings:

mds.signing-key = RANDOM_HEX_KEY
mds.token-key = RANDOM_HEX_KEY

You can generate random hex keys by running openssl rand -hex 32 and pasting its output.

Using Jetpack

Run jetpack without any arguments to see available commands. Use jetpack help COMMAND to see detailed help on individual commands.

To initialize the ZFS datasets and directory structure, run jetpack init.

To get a console, run:

jetpack run -t 3ofcoins.net/freebsd-base

This will fetch our signing GPG key, then fetch the FreeBSD base ACI, and finally run a pod and drop you into its console. After you exit the shell, run jetpack list to see the pod, and jetpack destroy UUID to remove id.

Run jetpack images to list available images.

You create pods from images, then run the pods:

jetpack prepare 3ofcoins.net/freebsd-base

Note the pod UUID printed by the above command (no user-friendly pod names yet) or get it from the pod list (run jetpack list to see the list). Then run the pod:

jetpack run -t $UUID

The above command will drop you into root console of the pod. After you're finished, you can run the pod again. Once you're done with the pod, you can destroy it:

jetpack destroy $UUID

You can also look at the "showenv" example:

make -C images/example.showenv
jetpack prepare example/showenv
jetpack run $UUID

To poke inside a pod that, like the "showenv" example, runs a useful command instead of a console, use the console subcommand:

jetpack console $UUID

Run jetpack help to see info on remaining available commands, and if something needs clarification, create an issue at https://github.com/3ofcoins/jetpack/ and ask the question. If something is not clear, it's a bug in the documentation!

Running the Metadata Service

To start the metadata service, run $(jetpack config path.libexec)/mds.

Building Images

See the IMAGES.md file for details. Some example image build scripts (including the published 3ofcoins.net/freebsd-base image) are provided in the images/ directory.

Features, or The Laundry List

  • Stage0
    • Image import from ACI
    • Image building
    • Clone pod from image and run it
    • Full pod lifecycle (Stage0/Stage1 interaction)
    • Multi-application pods
    • Image discovery
  • Stage1
    • Isolation via jails
    • Volumes
    • Multi-application pods
    • Firewall integration
    • Metadata endpoint
    • Isolators
  • Stage2
    • Main entry point execution
    • Setting UID/GID
    • Setting environment variables
    • Event Handlers
    • Isolators
  • CLI
    • Specify image/pod by name & labels, not only UUID
    • Consistent options for specifying application options (CLI, JSON file)
  • General TODO
    • Refactor the Thing/ThingManager/Host sandwich to use embedded fields
    • CLI-specified types.App fields for custom exec, maybe build parameters too?
    • Live, movable "tags" or "bookmarks", to mark e.g. latest version of an image without need to modify its manifest. Possible search syntax: name@tag1,tag2,…, where a tag is an ACName, so it may be also a key/value pair like environment/production. - [ ] Maybe some variant of tags that would be unique per name?
    • /etc/rc.d/jetpack (/etc/rc.d/jetpack_ for individual pods?) to start pods at boot time, and generally manage them as services
    • Port to install Jetpack system-wide
    • If/when we get enough live runtime data to make it complicated, maybe a centralized indexed storage, like SQLite? This could also solve some locking issues for long-running processes…