Accessing Jails Using SSH
3 minute read.Last Modified 2022-09-29 14:46 EDT
You must enable the ssh daemon sshd(8) in a jail to allow SSH access to that jail from another system.
The jail STATE must be up before the SHELL option is available.
When the jail is not up, start it by clicking Jails > and then the jail chevron_right, then click START for the desired jail. Click chevron_right, then SHELL to open a shell inside the jail:
FreeBSD 11.1-STABLE (FreeNAS.amd64) #0 0ale9f753(freenas/11-stable): FriApr 6 04:46:31 UTC 2018 Welcome to FreeBSD! Release Notes, Errata: https://www.FreeBSD.org/releases/ Security Advisories: https://www.FreeBSD.org/security/ FreeBSD Handbook: https://www.FreeBSD.org/handbook/ FreeBSD FAQ: https://www.FreeBSD.org/faq/ Questions List: https://lists.FreeBSD.org/mailman/listinfo/freebsd-questions/ FreeBSD Forums: https://forums.FreeBSD.org/ Documents installed with the system are in the /usr/local/share/doc/freebsd/ directory, or can be installed later with: pkg install en-freebsd-doc For other languages, replace "en" with a language code like de or fr. Show the version of FreeBSD installed: freebsd-version ; uname -a Please include that output and any error messages when posting questions. Introduction to manual pages: man man FreeBSD directory layout: man hier Edit /etc/motd to change this login announcement. root@jailexamp:~ #
The Shell can also open a jail root shell.
Open the Shell and enter command
iocage console jailname.
sysrc sshd_enable="YES" sshd_enable: NO -> YES
Start the SSH daemon:
service sshd start.
The first time the service runs, the jail RSA key pair is generated and the key fingerprint is displayed.
Add a user account with
adduser and follow the prompts.
Enter accepts the default value.
Users that require root access must also be a member of the
wheel when prompted to
invite user into other groups?
root@jailexamp:~ # adduser Username: jailuser Full name: Jail User Uid (Leave empty for default): Login group [jailuser]: Login group is jailuser. Invite jailuser into other groups? : wheel Login class [default]: Shell (sh csh tcsh git-shell zsh rzsh nologin) [sh]: csh Home directory [/home/jailuser]: Home directory permissions (Leave empty for default): Use password-based authentication? [yes]: Use an empty password? (yes/no) [no]: Use a random password? (yes/no) [no]: Enter password: Enter password again: Lock out the account after creation? [no]: Username : jailuser Password : ***** Full Name : Jail User Uid : 1002 Class : Groups : jailuser wheel Home : /home/jailuser Home Mode : Shell : /bin/csh Locked : no OK? (yes/no): yes adduser: INFO: Successfully added (jailuser) to the user database. Add another user? (yes/no): no Goodbye! root@jailexamp:~
After creating the user, set the jail root password to allow users to use
su to gain superuser privileges.
To set the jail root password, use
Nothing echoes back when using
root@jailexamp:~ # passwd Changing local password for root New Password: Retype New Password: root@jailexamp:~ #
Finally, test that the user can successfully
ssh into the jail from another system and gain superuser privileges.
In this example, a user named
ssh to access the jail at 192.168.2.3.
The host RSA key fingerprint must be verified the first time a user logs in.
ssh firstname.lastname@example.org The authenticity of host '192.168.2.3 (192.168.2.3)' can't be established. RSA key fingerprint is 6f:93:e5:36:4f:54:ed:4b:9c:c8:c2:71:89:c1:58:f0. Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.2.3' (RSA) to the list of known hosts. Password:
Every jail has its own user accounts and service configuration. These steps must be repeated for each jail that requires SSH access.