Ezjail host: Difference between revisions
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$ sudo portmaster /usr/ports/sysutils/ezjail | $ sudo portmaster /usr/ports/sysutils/ezjail | ||
</pre> | </pre> | ||
Then I go edit the ezjail config file <code>/usr/local/etc/ezjail.conf</code> and add/change these two lines neat the bottom: | |||
<pre> | |||
ezjail_use_zfs="YES" | |||
ezjail_jailzfs="cryptopool/jails" | |||
</pre> | |||
This makes ezjail use seperate zfs datasets under <code>cryptopool/jails</code> for the <code>basejail</code> and <code>newjail</code>, as well as for each jail created with the <code>-c zfs</code> option. | |||
Finally I populate <code>basejail</code> and <code>newjail</code> from the world I build earlier: | |||
<pre> | |||
$ sudo ezjail-admin update -i | |||
</pre> | |||
The last line of the output is a message saying: | |||
<pre> | |||
Note: a non-standard /etc/make.conf was copied to the template jail in order to get the ports collection running inside jails. | |||
</pre> | |||
This is because ezjail defaults to symlinking the ports collection in the same way it symlinks the basejail. I prefer having seperate/individual ports collections in each of my jails though, so I remove the symlink and make.conf from newjail: | |||
<pre> | |||
$ sudo rm /usr/jails/newjail/etc/make.conf /usr/jails/newjail/usr/ports | |||
</pre> | |||
Note that ezjail | |||
Revision as of 18:31, 22 July 2012
Background
This is my personal checklist for when I am setting up a new ezjail host. I like my jail hosts configured in a very specific way. There is a good chance that what is right for me is not right for you. For example, my filesystem layout is basically a zpool on top of a geli device created on a zvol exported from another zpool. If you decide to go with this layout you shouldn't expect blazing filesystem performance. I don't need filesystem blazing performance, but I do need encryption, and I do need ZFS, so this is just right for me :).
Also note that I talk a lot about the German hosting provider Hetzner, if you are using another provider or you are doing this at home, just ignore the Hetzner specific stuff. Much of the content here can be used with little or no changes outside Hetzner.
Installation
OS install with mfsbsd
After receiving the server from Hetzner I boot it using the rescue system which puts me at an mfsbsd prompt. I then edit the zfsinstall script /root/bin/zfsinstall and add "usr" to FS_LIST near the top of the script. I do this because I like to have /usr as a seperate ZFS dataset.
I then run the zfsinstall script like below. I am going to export the majority of the available diskspace as a ZVOL which will be used for a GELI device with another zfs pool on top. This pool will house the actual jails and data.
Note that the disks are new-ish (Power_On_Hours is 73 on both drives according to smartctl, which the mfsbsd author has been clever enough to include in mfsbsd) but I still found an MBR partition that needed to be deleted first. This can be done with the destroygeom command like shown below:
[root@rescue ~]# zfsinstall -d ad4 -d ad6 -r mirror -s 5G -t /nfs/mfsbsd/9.0-amd64-zfs.tar.xz
Error: /dev/ad4 already contains a partition table.
=> 63 5860533105 ad4 MBR (2.7T)
63 5860533105 - free - (2.7T)
You may erase the partition table manually with the destroygeom command
[root@rescue ~]# destroygeom
Usage: /root/bin/destroygeom [-h] -d geom [-d geom ...] [-p zpool ...]
[root@rescue ~]# destroygeom -d ad4 -d ad6
Destroying geom ad4:
Destroying geom ad6:
[root@rescue ~]# zfsinstall -d ad4 -d ad6 -r mirror -s 5G -t /nfs/mfsbsd/9.0-amd64-zfs.tar.xz
Creating GUID partitions on ad4 ... done
Configuring ZFS bootcode on ad4 ... done
=> 34 5860533101 ad4 GPT (2.7T)
34 2014 - free - (1.0M)
2048 128 1 freebsd-boot (64K)
2176 10485760 2 freebsd-swap (5.0G)
10487936 5850045199 3 freebsd-zfs (2.7T)
Creating GUID partitions on ad6 ... done
Configuring ZFS bootcode on ad6 ... done
=> 34 5860533101 ad6 GPT (2.7T)
34 2014 - free - (1.0M)
2048 128 1 freebsd-boot (64K)
2176 10485760 2 freebsd-swap (5.0G)
10487936 5850045199 3 freebsd-zfs (2.7T)
Creating ZFS pool tank on ad4p3 ad6p3 ... done
Creating tank root partition: ... done
Creating tank partitions: var tmp usr ... done
Setting bootfs for tank to tank/root ... done
NAME USED AVAIL REFER MOUNTPOINT
tank 210K 2.68T 21K none
tank/root 88K 2.68T 25K /mnt
tank/root/tmp 21K 2.68T 21K /mnt/tmp
tank/root/usr 21K 2.68T 21K /mnt/usr
tank/root/var 21K 2.68T 21K /mnt/var
Extracting FreeBSD distribution ... done
Writing /boot/loader.conf... done
Writing /etc/fstab...Writing /etc/rc.conf... done
Copying /boot/zfs/zpool.cache ... done
Installation complete.
The system will boot from ZFS with clean install on next reboot
You may type "chroot /mnt" and make any adjustments you need.
For example, change the root password or edit/create /etc/rc.conf for
for system services.
WARNING - Don't export ZFS pool "tank"!
[root@rescue]#
Finally to fix a small shortcoming in the zfsinstall script. It only enables swap on the first drive even though it creates swap partitions on all drives. I run the commands below to find the gptid of the swap partition not yet swapon'd. I run swapon on the gptid and check swapinfo output again to verify that it worked:
[root@rescue]# swapinfo Device 1K-blocks Used Avail Capacity /dev/gptid/e0f61e4f-a59e-11e1-9 5242880 0 5242880 0% [root@rescue]# glabel status ada0p2 | grep gptid gptid/e0f61e4f-a59e-11e1-93ed-e840f2090be0 N/A ada0p2 [root@rescue]# glabel status ada1p2 | grep gptid gptid/e20f4cc8-a59e-11e1-93ed-e840f2090be0 N/A ada1p2 [root@rescue]# swapon /dev/gptid/e20f4cc8-a59e-11e1-93ed-e840f2090be0 [root@rescue]# swapinfo Device 1K-blocks Used Avail Capacity /dev/gptid/e0f61e4f-a59e-11e1-9 5242880 0 5242880 0% /dev/gptid/e20f4cc8-a59e-11e1-9 5242880 0 5242880 0% Total 10485760 0 10485760 0% [root@rescue]#
Post install configuration (before reboot)
Before rebooting into the installed FreeBSD I need to make certain I can reach the server through SSH after the reboot. This means:
- Adding network settings to
/etc/rc.conf - Adding sshd_enable="YES" to
/etc/rc.conf - Change PermitRootLogin to Yes in
/etc/ssh/sshd_config - Finally I set the root password.
All of these steps are essential if I am going to have any chance of logging in after reboot. Most of these changes can be done from the mfsbsd shell but the password change requires chroot into the newly installed environment.
I use the chroot command but start another shell as bash is not installed in /mnt:
[root@rescue ~]# chroot /mnt/ csh rescue# ee /etc/rc.conf rescue# ee /etc/ssh/sshd_config rescue# passwd New Password: Retype New Password: rescue#
So, the network settings are sorted, root password is set, and root is permitted to ssh in. Time to reboot (this is the exciting part).
Creating the encrypted zvol
I export most of the available diskspace as a ZVOL which will be used to house a GELI volume.
[root@ ~]# zfs list NAME USED AVAIL REFER MOUNTPOINT tank 359M 2.68T 21K none tank/root 359M 2.68T 84.8M / tank/root/tmp 28K 2.68T 28K /tmp tank/root/usr 274M 2.68T 274M /usr tank/root/var 412K 2.68T 412K /var [root@ ~]# zfs create -V 2640G tank/gelizvol [root@ ~]# zfs list NAME USED AVAIL REFER MOUNTPOINT tank 2.66T 17.0G 21K none tank/gelizvol 2.66T 2.68T 16K - tank/root 359M 17.0G 84.8M / tank/root/tmp 28K 17.0G 28K /tmp tank/root/usr 274M 17.0G 274M /usr tank/root/var 412K 17.0G 412K /var [root@ ~]# ls -l /dev/zvol/tank/gelizvol crw-r----- 1 root operator 0, 124 May 24 13:10 /dev/zvol/tank/gelizvol [root@ ~]#
Then I create a geli key from /dev/random and initialize the geli provider:
[root@ ~]# dd if=/dev/random of=/root/encrypted.key bs=64 count=1
1+0 records in
1+0 records out
64 bytes transferred in 0.000031 secs (2064888 bytes/sec)
[root@ ~]# ls -l /root/encrypted.key
-rw-r--r-- 1 root wheel 64 May 24 13:14 /root/encrypted.key
[root@ ~]# geli init -s 512 -K /root/encrypted.key /dev/zvol/tank/gelizvol
Enter new passphrase:
Reenter new passphrase:
Metadata backup can be found in /var/backups/zvol_tank_gelizvol.eli and
can be restored with the following command:
# geli restore /var/backups/zvol_tank_gelizvol.eli /dev/zvol/tank/gelizvol
[root@ ~]#
Next is to attach the newly created geli provider:
[root@ ~]# geli attach -k /root/encrypted.key /dev/zvol/tank/gelizvol Enter passphrase: [root@ ~]# ls -l /dev/zvol/tank/ total 0 crw-r----- 1 root operator 0, 124 May 24 13:20 gelizvol crw-r----- 1 root operator 0, 127 May 24 13:22 gelizvol.eli [root@ ~]#
Now to create the zpool on top of the unlocked geli provider:
[root@ ~]# zpool create cryptopool /dev/zvol/tank/gelizvol.eli
[root@ ~]# zpool list
NAME SIZE ALLOC FREE CAP DEDUP HEALTH ALTROOT
cryptopool 2.56T 108K 2.56T 0% 1.00x ONLINE -
tank 2.72T 363M 2.72T 0% 1.00x ONLINE -
[root@ ~]# zpool status cryptopool
pool: cryptopool
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
cryptopool ONLINE 0 0 0
zvol/tank/gelizvol.eli ONLINE 0 0 0
errors: No known data errors
[root@ ~]#
The last remaining thing is to create a filesystem in the new zfs pool:
[root@ ~]# zfs list NAME USED AVAIL REFER MOUNTPOINT cryptopool 91K 2.52T 31K /cryptopool tank 2.66T 17.0G 21K none tank/gelizvol 2.66T 2.68T 1.16M - tank/root 359M 17.0G 84.8M / tank/root/tmp 28K 17.0G 28K /tmp tank/root/usr 274M 17.0G 274M /usr tank/root/var 419K 17.0G 419K /var [root@ ~]# zfs set mountpoint=none cryptopool [root@ ~]# zfs create -o compression=gzip -o mountpoint=/usr/jails cryptopool/jails [root@ ~]# zfs list NAME USED AVAIL REFER MOUNTPOINT cryptopool 149K 2.52T 31K none cryptopool/jails 31K 2.52T 31K /usr/jails tank 2.66T 17.0G 21K none tank/gelizvol 2.66T 2.68T 1.33M - tank/root 359M 17.0G 84.8M / tank/root/tmp 28K 17.0G 28K /tmp tank/root/usr 274M 17.0G 274M /usr [root@ ~]#
The next things are post-install configuration stuff like firewall and so on. The basic install is finished \o/
Upgrade OS (buildworld)
I usually run -STABLE on my hosts, which means I need to build and install a new world and kernel. I also like having rctl available on my jail hosts, so I can limit jail ressources in all kinds of neat ways. Additionally I also need the built world to populate ezjails basejail.
Fetching sources
I make a copy of the example config file, and set the servername to cvsup.de.FreeBSD.org using sed:
$ sudo cp /usr/share/examples/cvsup/stable-supfile /etc/ $ sudo sed -i "" "s/=CHANGE_THIS/=cvsup.de/g" /etc/stable-supfile $ sudo csup -L 2 /etc/stable-supfile
Create kernel config
After the sources finish downloading, I create a new kernel config file /etc/RCTL with the following content:
include GENERIC options RACCT options RCTL
I then create a symlink to the kernel config file in /etc/:
$ ln -s /etc/RCTL /usr/src/sys/amd64/conf/ $ ls -l /usr/src/sys/amd64/conf/RCTL lrwxr-xr-x 1 root wheel 9 Jul 22 16:14 /usr/src/sys/amd64/conf/RCTL -> /etc/RCTL
Building world and kernel
Finally I start the build. I use -j12 because I have 12 cores in this system. Check the number of cores in your system with sysctl:
$ sysctl hw.ncpu hw.ncpu: 12
To build the new system:
$ sudo make -j12 buildworld && sudo make -j12 buildkernel KERNCONF=RCTL && sudo make installkernel KERNCONF=RCTL && date
After the build finishes, reboot and run mergemaster -p, installworld, and mergemaster again:
$ sudo mergemaster -pFUi && sudo make installworld && sudo mergemaster -FUi
DO NOT OVERWRITE /etc/group AND /etc/master.passwd AND OTHER CRITICAL FILES!
Reboot after the final mergemaster completes, and boot into the newly built world.
Configuration
This section outlines what I do to further prepare the machine to be a nice ezjail host.
Firewall
One of the first things I fix is to enable the pf firewall from OpenBSD. I add the following to /etc/rc.conf to enable pf at boot time:
[root@ ~]# grep pf /etc/rc.conf pf_enable="YES" pflog_enable="YES" [root@ ~]#
I also create a very basic /etc/pf.conf:
[root@ ~]# cat /etc/pf.conf
### macros
if="em0"
table <portknock> persist
#external addresses
tykv4="a.b.c.d"
tykv6="2002:ab:cd::/48"
table <allowssh> { $tykv4,$tykv6 }
#local addresses
glasv4="w.x.y.z"
### scrub
scrub in on $if all fragment reassemble
### filtering
#block everything
block log all
#skip loopback interface(s)
set skip on lo0
################
# pass ipv6 fragments (hack to workaround pf not handling ipv6 fragments)
pass in on $if inet6
block in log on $if inet6 proto udp
block in log on $if inet6 proto tcp
block in log on $if inet6 proto icmp6
block in log on $if inet6 proto esp
block in log on $if inet6 proto ipv6
#pass outgoing
pass out quick on $if all
#pass incoming ssh and icmp
pass in quick on $if proto tcp from { <allowssh> } to ($if) port 22
pass in quick on $if inet proto icmp all icmp-type { 8, 11 }
To load pf without rebooting I run the following:
[root@ ~]# kldload pf [root@ ~]# kldload pflog [root@ ~]# pfctl -f /etc/pf.conf && sleep 60 && pfctl -d No ALTQ support in kernel ALTQ related functions disabled
I get no prompt after this because pf has cut my SSH connection. But I can SSH back in if I did everything right, and if not, I can just wait 60 seconds after which pf will be disabled again. I SSH in and reattach to the screen I am running this in, and press control-c, so the "sleep 60" is interrupted and pf is not disabled. Neat little trick for when you want to avoid locking yourself out :)
Listening daemons
When you add an IP alias for a jail, any daemons listening on * will also listen on the jails IP, which is not what I want. For example, I want the jails sshd to be able to listen on the jails IP on port 22, instead of the hosts sshd. Check for listening daemons like so:
$ sockstat -l46 USER COMMAND PID FD PROTO LOCAL ADDRESS FOREIGN ADDRESS root master 1554 12 tcp4 *:25 *:* root master 1554 13 tcp6 *:25 *:* root sshd 948 3 tcp6 *:22 *:* root sshd 948 4 tcp4 *:22 *:* root syslogd 789 6 udp6 *:514 *:* root syslogd 789 7 udp4 *:514 *:* [tykling@glas ~]$
This tells me that I need to change Postfix, sshd and syslogd to stop listening on all IP addresses.
Postfix
The defaults in Postfix are really nice on FreeBSD, and most of the time a completely empty config file is fine for a system mailer (sendmail replacement). However, to make Postfix stop listening on port 25 on all IP addresses, I do need one line in /usr/local/etc/postfix/main.cf:
$ cat /usr/local/etc/postfix/main.cf inet_interfaces=localhost $
sshd
To make sshd stop listening on all IP addresses I uncomment and edit the ListenAddress line in /etc/ssh/sshd_config:
$ grep ListenAddress /etc/ssh/sshd_config ListenAddress x.y.z.226 #ListenAddress ::
(IP address obfuscated..)
syslogd
I don't need my syslogd to listen on the network at all, so I add the following line to /etc/rc.conf:
$ grep syslog /etc/rc.conf syslogd_flags="-ss"
Restarting services
Finally I restart Postfix, sshd and syslogd:
$ sudo /etc/rc.d/syslogd restart Stopping syslogd. Waiting for PIDS: 789. Starting syslogd. $ sudo /etc/rc.d/sshd restart Stopping sshd. Waiting for PIDS: 948. Starting sshd. $ sudo /usr/local/etc/rc.d/postfix restart postfix/postfix-script: stopping the Postfix mail system postfix/postfix-script: starting the Postfix mail system
A check with sockstat reveals that no more services are listening on all IP addresses:
$ sockstat -l46 USER COMMAND PID FD PROTO LOCAL ADDRESS FOREIGN ADDRESS root master 1823 12 tcp4 127.0.0.1:25 *:* root master 1823 13 tcp6 ::1:25 *:* root sshd 1617 3 tcp4 x.y.z.226:22 *:* $
Bootstrapping ezjail
First I install /usr/ports/sysutils/ezjail using Portmaster:
$ sudo portmaster /usr/ports/sysutils/ezjail
Then I go edit the ezjail config file /usr/local/etc/ezjail.conf and add/change these two lines neat the bottom:
ezjail_use_zfs="YES" ezjail_jailzfs="cryptopool/jails"
This makes ezjail use seperate zfs datasets under cryptopool/jails for the basejail and newjail, as well as for each jail created with the -c zfs option.
Finally I populate basejail and newjail from the world I build earlier:
$ sudo ezjail-admin update -i
The last line of the output is a message saying:
Note: a non-standard /etc/make.conf was copied to the template jail in order to get the ports collection running inside jails.
This is because ezjail defaults to symlinking the ports collection in the same way it symlinks the basejail. I prefer having seperate/individual ports collections in each of my jails though, so I remove the symlink and make.conf from newjail:
$ sudo rm /usr/jails/newjail/etc/make.conf /usr/jails/newjail/usr/ports
Note that ezjail
