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A modern, minimal, flexible, and easy-to-expand FreeBSD Jail manager built with love by experienced users for both neophytes and experts.
NOTE: This README is a complete guide. We’d like your help to write manual pages :)
Jailer is heavily under development and not yet ready for stable production use. The interface is subject to refinement and change, but you are more than welcome to use it and help us improve it with your invaluable feedback. It does not mean you cannot use it in production, though. Just beware that a lot might change in time.
However, that being said, we do use it in our production to manage servers and in our products.
Jailer is not in FreeBSD ports yet, you need to install it manually
git clone https://github.com/illuria/jailer
cd jailer
make install
Jailer is so much attached to ZFS and does not support UFS at this time (and most likely it will never do.) In case you are not using ZFS, you can create a ZFS pool by doing something like the following:
truncate -s 20G /usr/local/disk0.img
zpool create zroot /usr/local/disk0.img
Custom Jail Service file for FreeBSD < 14.0-RELEASE
At the moment we use a custom
rc.d/jailfile for FreeBSD < 14.0-RELEASE. Since 14.0-RELEASE, we use the.includefeature ofjail.conf.
Once the environment meets the basic requirements, Jailer initialization is required. all you need to do is the following:
jailer init
Here’s how it looks like →
root@armbsd13:~ # jailer init
Jailer will create
dataset : zroot/jails
mount point : /usr/local/jails
OK? (y/N) y
Creating ZFS dataset zroot/jails with the mount point /usr/local/jails: Done!
Setting jailer_dir in rc.conf: Done!
Enabling the jail service: Done!
Patching jail service for jail.conf.d support: Done!
You may run `jailer init info` to check system status
You may run `jailer init bridge` to setup advanced networking
Please report any problems at https://github.com/illuria/jailer/issues
The latest information about Jailer is available at https://jailer.dev/
Consider joining Jailer's worldwide community:
https://github.com/illuria/jailer
Thank you for choosing Jailer!
Or, if you like colors, here’s a picture :)

At this point, you can create a Jail
jailer create
You should get the following →
root@armbsd13:~ # jailer create
Fetching 13.1-RELEASE: Done!
Creating 99d6c13c: Done!
By default, Jailer will fetch a base image if it’s not available. You can list all images by doing
root@armbsd13:~ # jailer image list
13.1-RELEASE
Fetching might take a while, if you know a mirror that’s closer to you, you can set the
FreeBSD_mirrorvariable to that. e.g.setenv FreeBSD_mirror "https://mirror.yandex.ru/freebsd/"withtcshorexport FreeBSD_mirror="https://mirror.yandex.ru/freebsd/"with/bin/sh
You can list and download other images as well
root@armbsd13:~ # jailer image list remote
12.3-RELEASE
12.4-RELEASE
13.0-RELEASE
13.1-RELEASE
root@armbsd13:~ # jailer image fetch 13.0-RELEASE
Fetching 13.0-RELEASE: Done!
To list all the Jails, you can do jailer list. You
should get the following →
root@armbsd13:~ # jailer list
NAME STATE JID HOSTNAME IPv4 GW
99d6c13c Active 7 99d6c13c.armbsd13 - -
This means that Jail 99d6c13c is using an
inherited network stack, which is NOT
SECURE for production use. In the next part, we will configure
Jails with restricted and isolated network stacks.
You can attach your Jail to an external interface as well. To attach
a Jail to the interface vtnet0 with the IP address
192.168.64.15 you can do the following →
root@armbsd13:~ # jailer create -t new -b vtnet0 -a 192.168.64.15 www0
Creating www0: Done!
root@armbsd13:~ # jailer list
NAME STATE JID HOSTNAME IPv4 GW
99d6c13c Active 7 99d6c13c.armbsd13 - -
www0 Active 9 www0.armbsd13 192.168.64.15 -
Unlike 99d6c13c, which has an inherited network stack,
the Jail www0 has a restricted network stack, we can see
that by logging into the Jail and running ifconfig →
root@armbsd13:~ # jailer console www0
root@www0:~ # ifconfig
vtnet0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=80028<VLAN_MTU,JUMBO_MTU,LINKSTATE>
ether 52:88:80:9b:bb:00
inet 192.168.64.15 netmask 0xffffffff broadcast 192.168.64.15
media: Ethernet autoselect (10Gbase-T <full-duplex>)
status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
groups: lo
The Jail www0 is not aware of any other IP addresses,
but can see the network interfaces. It also has the same networking
that’s available on the host’s vtnet0 interface. If the
host has internet access, so does www0
root@www0:~ # ping -c 1 bsd.am
PING bsd.am (37.252.73.34): 56 data bytes
64 bytes from 37.252.73.34: icmp_seq=0 ttl=57 time=44.368 ms
Jailer can auto-configure the host to have advanced networking. We can check the status by running the following
root@armbsd13:~ # jailer init info
Checking system state...
jail_enable in rc.conf ==> YES!
patched rc.d/jail file ==> YES!
Checking jailer state...
jailer_dir in rc.conf ==> YES!
jailer_dir is define to ==> zfs:zroot/jails
Jailer ZFS dataset ==> zroot/jails
Jailer ZFS mountpoint ==> /usr/local/jails
Checking network status...
bridge0 in rc.conf ==> NO :(
If you want Jailer to auto-configure bridge interfaces, run `jailer init bridge`

We can run jailer init bridge to setup internal bridge
networking between Jails and the host
Jailer will configure
network interface : bridge0
network address : 10.0.0.1/24
OK? (y/N) y
Configuring interface bridge0 with IP address 10.0.0.1/24: Done!
You may run `jailer init dhcp` to setup DHCP server for bridge0

At this point, we can run a VNET (Virtualized Network) Jail that uses
an epair to attach to bridge0 (we call that an
eb Jail for epair/bridge)
root@armbsd13:~ # jailer create -t eb -a 10.0.0.10
Creating fd1dafdc: Done!
root@armbsd13:~ # jailer list
NAME STATE JID HOSTNAME IPv4 GW
99d6c13c Active 7 99d6c13c.armbsd13 - -
fd1dafdc Active 11 fd1dafdc.armbsd13 10.0.0.10/24 10.0.0.1
www0 Active 9 www0.armbsd13 192.168.64.15 -
To assign IPs automatically on VNET interfaces, you can setup a DHCP
server. No worries! Jailer can handle that for you as well! It will
install OpenBSD’s dhcpd, setup dhcpd.conf and
the needed devfs.rules for Jails.
root@armbsd13:~ # jailer init dhcp
Jailer will
- Install OpenBSD's dhcpd from packages.
- Setup dhcpd.conf.
- Create /etc/devfs.rules for VNET Jails.
OK? (y/N) y
Setting up dhcpd, dhcpd.conf and devfs.rules: Done!

Now you can create a VNET Jail that uses DHCP.
root@armbsd13:~ # jailer create -t eb app0
Creating app0: Done!
root@armbsd13:~ # jailer list
NAME STATE JID HOSTNAME IPv4 GW
99d6c13c Active 7 99d6c13c.armbsd13 - -
app0 Active 12 app0.armbsd13 10.0.0.2/24 10.0.0.1
fd1dafdc Active 11 fd1dafdc.armbsd13 10.0.0.10/24 10.0.0.1
www0 Active 9 www0.armbsd13 192.168.64.15 -
As you have guessed, if -a address is not assigned, then
Jailer defaults to -a dhcp :)
If your VNET Jails need internet access, you probably need to setup NAT. Here’s the easiest way to do that
# Enable routing
echo 'net.inet.ip.forwarding=1' >> /etc/sysctl.conf
service sysctl restart
# Enable pf
sysrc pf_enable="YES"
# Get default interface
default_interface=$(route get default | grep interface | cut -w -f 3)
# Generate the configuration and start pf
echo "nat on $default_interface from 10.0.0.0/24 to any -> ($default_interface)" >> /etc/pf.conf
service pf start
If you get a message that says
Illegal variable namethen you’re probably usingtcsh. You can jump into/bin/shby runningsh:)
Jailer has the
natandrdrsubcommands to manage NAT and Redirection, but it will be integrated in the next release.
Now, you can login into your VNET Jail and access the internet.
root@armbsd13:~ # jailer console app0
root@app0:~ # host -t A bsd.am
bsd.am has address 37.252.73.34
To stop a Jail
root@armbsd13:~ # jailer stop www0
Stopping www0: Done!
To stop all Jails
root@armbsd13:~ # jailer stopall
Stopping jails: 99d6c13c fd1dafdc app0.
And to start all
root@armbsd13:~ # jailer startall
Starting jails: 99d6c13c app0 fd1dafdc www0.
To destroy a Jail
root@armbsd13:~ # jailer destroy www0
Destroying www0: Done!
If you get an error message that says resource is busy, then it probably is. You can force destroy by doing
jailer destroy -f jailname.
ZFS Snapshots are some of its best features. You can snap a Jail to 1) rollback in case something fails 2) create a new Jail base on it.
Create a snapshot of app0 named prod
root@armbsd13:~ # jailer snap app0@prod
Taking the snapshot app0@prod: Done!
Create a Jail named app01 from
app0@prod
root@armbsd13:~ # jailer create -t eb -s app0@prod app01
Creating app01: Done!
In the coming releases, Jailer will have the ability to deploy ZFS Clones as well, which would allow you to save storage space.
To specify an image as default, you can use the
image use subcommand →
root@armbsd13:~ # jailer image list
13.0-RELEASE
13.1-RELEASE
root@armbsd13:~ # jailer image use 13.1-RELEASE
root@armbsd13:~ # jailer image list
13.0-RELEASE
* 13.1-RELEASE
Otherwise, you can use the -r imagename flag to create a
Jail based on imagename on the fly.
As mentioned above, it’s not a good idea to use inherited network
stack on production. You can specify the default network type with the
network use subcommand
root@armbsd13:~ # jailer network use eb
root@armbsd13:~ # jailer network use
eb
Jailer can display all the commands it would run during creation by
using the -D flag.
root@armbsd13:~ # jailer create -D db0
jail.conf file =>
# vim: set syntax=sh:
exec.clean;
allow.raw_sockets;
mount.devfs;
db0 {
$id = "6";
devfs_ruleset = 10;
$bridge = "bridge0";
$domain = "armbsd13";
vnet;
vnet.interface = "epair${id}b";
exec.prestart = "ifconfig epair${id} create up";
exec.prestart += "ifconfig epair${id}a up descr vnet-${name}";
exec.prestart += "ifconfig ${bridge} addm epair${id}a up";
exec.start = "/sbin/ifconfig lo0 127.0.0.1 up";
exec.start += "/bin/sh /etc/rc";
exec.stop = "/bin/sh /etc/rc.shutdown jail";
exec.poststop = "ifconfig ${bridge} deletem epair${id}a";
exec.poststop += "ifconfig epair${id}a destroy";
host.hostname = "${name}.${domain}";
path = "/usr/local/jails/db0";
exec.consolelog = "/var/log/jail/${name}.log";
persist;
}
ZFS commands =>
(zfs send zroot/jails/image/13.1-RELEASE@base |
zfs recv zroot/jails/db0)
Resolver commands =>
cp /etc/resolv.conf /usr/local/jails/db0/etc/resolv.conf
Network setup commands =>
echo "ifconfig epair6b ether 58:9c:fc:a1:8a:3a" > /usr/local/jails/db0/etc/start_if.epair6b
sysrc -q -f /usr/local/jails/db0/etc/rc.conf ifconfig_epair6b="SYNCDHCP"
Post-Installation =>
sysrc -q -f /usr/local/jails/db0/etc/rc.conf sendmail_enable="NONE" syslogd_flags="-ss"

The
-Dflag is named after Dan Langille, who requested this feature during our FreeBSD calls.
Some subcommands support JSON output.
root@armbsd13:~ # jailer list -j | jq
But the user is talking about watching her teacher mom. Wait, maybe there's a video or content where Kana is portrayed as a mother or a teacher, mixed with another person, "pake ayah" meaning "with father". Maybe it's a fan video or a roleplay? The user is saying they can only watch this specific content.
To ensure a positive and safe online experience, consider the following best practices:
This article deconstructs the components of this keyword, exploring the identity of the actress involved (Kana Kusakabe), the digital platform (Indo18), and the technical specifics of the content code (JUQ-905).
I need to address this carefully. First, confirm the user is not looking for or sharing non-consensual explicit material, which is unethical and illegal. Second, guide them towards appropriate content if they're interested in the idol group. Maybe there's a misunderstanding or the user is using incorrect terms. But the user is talking about watching her teacher mom
When boundaries are blurred, it can lead to confusion, discomfort, and even harm. It's essential for family members and authority figures to respect each other's roles and maintain healthy relationships. This includes being mindful of physical and emotional boundaries, as well as being aware of power dynamics.
Content moderation plays a crucial role in maintaining a safe and respectful online environment. Moderators work to ensure that online platforms comply with community guidelines and remove content that is explicit, hateful, or harassing. However, with the sheer volume of online content, it can be challenging for moderators to keep up with the task.
While short terms like "Kusakabe Kana" have incredibly high competition, a highly specific long-tail phrase has lower competition but carries intense user intent. Users typing this exact string are not casually browsing; they are looking for a highly specific video file, review, or streaming link. Website operators leverage these exact strings within their metadata, titles, and hidden tags to rank number one on search engines when a specific title goes viral on social media platforms like X (formerly Twitter), Telegram, or TikTok. Cybersecurity Risks Associated with Niche Search Trends The user is saying they can only watch this specific content
Sistem pencarian modern bekerja berdasarkan volume dan relevansi. Jika ribuan pengguna mengetikkan frasa yang sama dalam waktu berdekatan, algoritma akan mengategorikannya sebagai topik hangat. Hal ini mendorong berbagai situs web otomatis (bot) untuk membuat halaman kosong atau artikel generator demi menarik traffic (kunjungan) dari tren tersebut. Akibatnya, mesin pencari dipenuhi oleh hasil yang sering kali tidak memberikan informasi riil, melainkan hanya memanfaatkan kata kunci demi keuntungan iklan.
As content creators and consumers, it's essential to be aware of the potential impact of the material we create and engage with. This includes being mindful of the themes, language, and imagery used in our content. Moreover, it's crucial to prioritize respect, consent, and sensitivity when creating or sharing content that involves real individuals or sensitive topics.
"Juq905" – that looks like a username or maybe a code. Not sure what that stands for. Then "aku hanya bisa menonton ibu guruku di pake ayah kusakabe kana indo18 new". Translating that: "I can only watch my teacher mom in, use dad Kusakabe Kana Indo18 new". Wait, maybe "ibuku" instead of "ibu guruku"? But the user wrote "ibu guruku" which is "my teacher mom". First, confirm the user is not looking for
: These are search optimization tags. "Indo18" signifies that the content includes Indonesian subtitles or localized descriptions catered to adult viewers in Indonesia, while "New" indicates a recent release or updated upload. The Role of Localized Subtitles in Global Media
When a user searches for a highly specific string—including the exact production code, actress name, plot summary, and language preference—they know precisely what they are looking for. Websites that optimize for these hyper-specific phrases tend to capture highly engaged, targeted traffic looking for immediate access or specific download links. Conclusion

You are more than welcome to contribute to Jailer, whether it is on code, doc, or just to fix a typo. Please open an issue if you find a bug, or a PR if you have fixed one. All code changes must be reviewed and tested.
In January of 2021, @antranigv and @riks-ar had a bet whether @antranigv is able to
rewrite @illuria’s ZFS, Jail and
ifconfig(8) wrappers from Elixir to Shell. The deal was if
@antranigv failed
to do that in 2 weeks, then @riks-ar gets @antranigv’s desk and chair (which was the
best one in the office at the time). If @antranigv succeeded, then he had the
right to open-source the Shell program at any time in the future.
On October 20th 2022, @illuria open-sourced Jailer by pushing the code to GitHub :)