AwesomO: Created page with " ==FreeBSD Jail Setup Manually== Creating a FreeBSD jail manually involves downloading and extracting the base package for the desired FreeBSD release. Here's a step-by-step guide on how to do this: ===Using OpenZFS=== '''OpenZFS''' is a very powerful and helpful File-System that can allow us to very easily '''create''', '''clone''', '''snapshot''', '''restore''', '''destroy''', '''backup''' and '''transfer''' are jails. ====Create a directory for the jail==== In..."

2023-05-05T14:51:07Z

Created page with " ==FreeBSD Jail Setup Manually== Creating a FreeBSD jail manually involves downloading and extracting the base package for the desired FreeBSD release. Here's a step-by-step guide on how to do this: ===Using OpenZFS=== '''OpenZFS''' is a very powerful and helpful File-System that can allow us to very easily '''create''', '''clone''', '''snapshot''', '''restore''', '''destroy''', '''backup''' and '''transfer''' are jails. ====Create a directory for the jail==== In..."

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==FreeBSD Jail Setup Manually==

Creating a FreeBSD jail manually involves downloading and extracting the base package for the desired FreeBSD release. Here's a step-by-step guide on how to do this:

===Using OpenZFS===

'''OpenZFS''' is a very powerful and helpful File-System that can allow us to very easily '''create''', '''clone''', '''snapshot''', '''restore''', '''destroy''', '''backup''' and '''transfer''' are jails.

====Create a directory for the jail====

In this example my ZFS Pool is called '''nuc''' and my '''jails directory''' will be in a directory called '''pods''' which will contain my '''jails''' each in a separate sub directory like so '''/pods/{jail1,jail2,jail3}'''

* Create a dataset for pods

<code>sudo zfs create nuc/pods</code>

* You can check with <code>zfs list</code> to see your new dataset.

====Set the mountpoint for the pods dataset====

<code>sudo zfs set mountpoint=/pods nuc/pods</code>

====Create a Template Jail Which you can clone====

In this section, we will create an OpenZFS dataset called '''FreeBSD_13.2_Template''' to extract a '''base.txz''' Which we will '''snapshot''' , and then '''clone''' the template to create a new jail.

=====Create the 'FreeBSD_13.2_Template' dataset=====

<code>sudo zfs create your_pool_name/path/FreeBSD_13.2_Template</code>

Replace your_pool_name with the name of your ZFS pool.

* Example:
<code>sudo zfs create nuc/pods/FreeBSD_13.2_Template</code>

=====Set the mountpoint for the template dataset=====

<code>sudo zfs set mountpoint=/pods/FreeBSD_13.2_Template nuc/pods/FreeBSD_13.2_Template</code>

=====Download the '''base.txz''' package for FreeBSD 13.2-RELEASE=====

<code>fetch https://download.freebsd.org/ftp/releases/amd64/13.2-RELEASE/base.txz -o /tmp/base.txz</code>

=====Extract the base.txz package to the 'FreeBSD_13.2_Template' dataset=====

<code>tar -C /pods/FreeBSD_13.2_Template -xf /tmp/base.txz</code>

=====Create a snapshot of the template dataset=====

<code>sudo zfs snapshot nuc/pods/FreeBSD_13.2_Template@base_snapshot</code>

=====Clone the template dataset to create a new jail dataset=====

<code>sudo zfs clone nuc/pods/FreeBSD_13.2_Template@base_snapshot nuc/pods/mediawiki</code>

=====Set the mountpoint for the jail dataset=====

<code>sudo zfs set mountpoint=/pods/mediawiki nuc/pods/mediawiki</code>

You now have a template dataset and a jail dataset based on that template.

====How to '''snapshot''' and '''rollback''' your jails====

Now, you have separate datasets for each jail, and you can create snapshots and rollbacks for each jail individually. For example, to create a snapshot for the mediawiki jail, you can run:

<code>sudo zfs snapshot nuc/pods/mediawiki@snapshot_name</code>

And to roll back to a snapshot for the mediawiki jail, you can run:

<code>sudo zfs rollback nuc/pods/mediawiki@snapshot_name</code>

Replace '''snapshot_name''' with a descriptive name for the snapshot. You can follow the same process for any other jails you create within the pods dataset.

====Destroy/Delete Dataset/jail====

If you need/want to delete the jail dataset, you can destroy it with the following command

First un-mount the mount point (if mounted)
* Find if and where mounted with:
<code>zfs list</code>
: Return out put:
<pre>nuc/pods/mediawiki 0B 208G 503M /pods/mediawiki
</pre>

As we can see its mounted at '''/pods/mediawiki'''
* ensure that no processes are currently using it.
You can use the '''fuser''' command followed by the path to the mount point to check for any processes that are using it.
:* For example: <code>fuser /pods/mediawiki</code>

* Unmount /pods/mediawiki
<code>sudo umount /pods/mediawiki</code>

* Now destroy the dataset
<code>sudo zfs destroy nuc/pods/mediawiki</code>

Replace '''nuc''' with the name of your ZFS pool.

* If you want to also remove any snapshots of the dataset, you can add the '''-R''' option to the '''zfs destroy''' command.
For example, to delete the dataset and all its snapshots, run the following command:

<code>zfs destroy -R nuc/pods/mediawiki</code>

===Using UFS===

====Create a directory====
Create a directory that will serve as the root directory for your jail. Replace '''/var/pods''' with the desired path.

<code>mkdir -pv /pods/mediawiki</code>

:* We now have a directory called '''pods''' in which we will install are jailed FreeBSD instances
:** With sub-directory '''mediawiki''' in which we will install are jailed mediawiki server

====Choose the desired FreeBSD release====
*Determine the FreeBSD release you want to use for your jail.
Search https://download.freebsd.org/ftp/releases/ For a '''base.txz'' of the version and appropriate architecture of FreeBSD you wish to install in a jail.

In this example, we'll use FreeBSD 13.2-RELEASE. Adjust the release version according to your needs.

Download the base package for the desired FreeBSD release. Use the '''fetch''' command to download the package directly from the FreeBSD website:

<code>fetch https://download.freebsd.org/ftp/releases/amd64/13.2-RELEASE/base.txz -o /tmp/base.txz</code>

:* Replace '''amd64''' with the appropriate architecture if needed.

====Extract the base package====

Extract the downloaded base package into the jail's root directory:

<code>tar -C /pods/mediawiki -xf /tmp/base.txz</code>

===jail configuration '''/etc/jail.conf'''===

Create a configuration file for your jail. The following example assumes you're using the jail utility provided by FreeBSD:

Edit '''/etc/jail.conf''' and add the following jail configuration:
* If '''/etc/jail.conf''' does not exist, create it with <code>touch /etc/jail.conf</code>
<code>$EDITOR /etc/jail.conf</code>

<pre>
localwiki {
host.hostname = "local.wiki";
ip4.addr = 192.168.0.33;
path = "/pods/mediawiki";
exec.start = "/bin/sh /etc/rc";
exec.stop = "/bin/sh /etc/rc.shutdown";
exec.clean;
mount.devfs;
}
</pre>

:* Replace
:** '''localwiki''' to what you would like your jail called
:** '''host.hostname = "<the_host_name_for_jail>";'''
:** '''ip4.addr = <ip_address_for_jail_to_use>;'''
:** '''path = "</path/to/jail>";'''

===Copy over your '''/etc/resolv.conf''' to jail===

It is generally a good idea to copy the '''/etc/resolv.conf''' file from the host system to the jail's '''/etc/resolv.conf''' before starting the jail. This ensures that the jail has the same DNS resolver configuration as the host, allowing it to resolve domain names correctly.

'''/etc/resolv.conf''' is a configuration file used by the DNS resolver library on Unix-based systems, including FreeBSD. It contains information about the DNS nameservers and search domains to use when resolving domain names.

To copy the '''resolv.conf''' file from the host system to the jail, you can use the cp command:

<code>cp /etc/resolv.conf /pods/mediawiki/etc/resolv.conf</code>

Make sure to execute this command before starting the jail to ensure proper DNS resolution within the jail environment.
===Start the jail===

Start the jail using the '''jail''' utility:

<code>jail -c localwiki</code>

Replace '''localwiki''' with the name you chose in the jail configuration.

===If you have firewall up - allow jail through firewall===

<div class="toccolours mw-collapsible mw-collapsed">
IPFW Example:
<div class="mw-collapsible-content">
<pre>
# Allow incoming traffic for jail's IP (192.168.0.33)
ipfw -q add 00200 allow all from any to 192.168.0.33 in

# Allow outgoing traffic for jail's IP (192.168.0.33)
ipfw -q add 00210 allow all from 192.168.0.33 to any out
</pre>
</div>
</div>

===Access the jail===

Enter the jail's environment with the '''jexec''' command:

<code>jexec localwiki /bin/sh</code>
* Replace '''localwiki''' with your jail name
You'll now be inside your jail, and you can manage it like any other FreeBSD system.

===Restart the jail===

:To restart the jail you turn it off and on again :)

<code>sudo jail -r your_jail_name</code>

<code>sudo jail -c your_jail_name</code>
* or one line
<code>sudo jail -r your_jail_name && sudo jail -c your_jail_name</code>

===Stop and remove the jail (optional)===

If you want to stop and remove the jail, first exit the jail environment (if you're still inside) by typing '''exit'''. Then, stop the jail:

<code>jail -r myjail</code>

You can now remove the jail directory and its contents:

<code>rm -rf /path/to/jail</code>

Don't forget to remove the corresponding jail configuration from '''/etc/jail.conf'''.

By following these steps, you've manually created a FreeBSD jail by downloading and extracting the base package. You can now configure and manage the jail as needed.

==Start Jails at reboot==

* To have all the jails start at reboot add the line <code>jail_enable="YES"</code> into rc.conf
<code>sysrc jail_enable="YES"</code>

==Run commands in jail from Host==

Start your jail, if it's not already running:

<code>sudo service jail start your_jail_name</code>

* Or use '''jail'''
<code>jail -c your_jail_name</code>

===Obtain the jail ID by listing the running jails===

<code>jls</code>

Note the JID (Jail ID) for your specific jail from the output.

===Update the pkg package manager inside the jail===

<code>sudo jexec JID pkg update</code>

Replace '''JID''' with the jail '''ID''' you noted in '''Obtain the jail ID by listing the running jails'''.

* Example (If JID = 1):
<code>sudo jexec 1 pkg update</code>

===Install packages using the pkg command with jexec===

<code>sudo jexec JID pkg install package_name</code>

Replace '''package_name''' with the desired package.

For example, to initialize pkg and install the nano text editor in a jail with a '''Jail ID of 1''', you would run:

<code>sudo jexec 1 pkg update</code>

<code>sudo jexec 1 pkg install nano</code>

To run other commands inside the jail from the host, you can use the same '''jexec JID command''' pattern, replacing command with the desired command you want to run inside the jail.

FreeBSD 13.2 Jails - Revision history