Learn how to - How To Configure FreeIPA Client on Ubuntu / CentOS 7

Felix Williams CentOS LDAP Linux Tutorials Ubuntu February 26, 2023

Learn how to – How To Configure FreeIPA Client on Ubuntu / CentOS 7.

We recently covered the installation of FreeIPA Server on Ubuntu server. In this guide, I’ll show you how you can install and configure FreeIPA Client on Ubuntu 22.04/20.04/18.04/16.04 & CentOS 7 Linux system. FreeIPA is an open source Identity management system sponsored by Red Hat. It aims to provide an easily managed Identity, Policy, and Audit.

For Vanilla LDAP, use: How to configure LDAP Client on Ubuntu

Setup Prerequisite:

Install FreeIPA Server
Installed and updated Ubuntu 22.04/20.04/18.04/16.04 / CentOS 7
Root access

If you don’t have FreeIPA server ready, check:

Once the installation of FreeIPA Server is complete, setup FreeIPA Client using steps covered here.

Step 1: Update system

We always start server configurations by doing an update of system packages:

Ubuntu:

sudo apt update && sudo apt -y full-upgrade
[ -f /var/run/reboot-required ] && sudo reboot -f

CentOS:

Update CentOS with the following commands:

sudo yum -y update

If you get kernel updates, consider rebooting the server for changes to take place.

Configure valid client hostname (FQDN) :

sudo hostnamectl set-hostname node-01.ownyourlife.com.ng

Step 2: Install FreeIPA Client

FreeIPA client is available on repositories for Ubuntu / CentOS Linux. Install it using the command:

Ubuntu:

Below are the commands you’ll use to install FreeIPA Client on Ubuntu system.

sudo apt-get install freeipa-client

CentOS 7:

Install FreeIPA Client on CentOS 7 with the command below.

sudo  yum -y install ipa-client

When prompted to provide a Kerberos realm for the server, just skip by pressing <Enter> key.

How To Configure FreeIPA Client on Ubuntu / CentOS 7 1

Install FreeIPA Client on CentOS 7

Run the command below to install FreeIPA Client on CentOS 7.

sudo yum install ipa-client

This will be configured in the next step:

Step 3: Configure FreeIPA Client on Ubuntu / CentOS 7

Once the installation of client package is complete. Add hostname and IP address of your IPA Server to /etc/hosts file:

$ sudo vim /etc/hosts
# Add FreeIPA Server IP and hostname
192.168.58.121 ipa.ownyourlife.com.ng ipa

Replace:

192.168.58.121 IP address of your FreeIPA replica or master server.
ipa.ownyourlife.com.ng with its hostname:

Then configure IPA client on this server so that users can start authenticating against it:

$ sudo ipa-client-install --hostname=`hostname -f` 
--mkhomedir 
--server=ipa.ownyourlife.com.ng 
--domain ownyourlife.com.ng 
--realm COMPUTINGFORGEEKS.COM

Autodiscovery of servers for failover cannot work with this configuration.
If you proceed with the installation, services will be configured to always access the discovered server for all operations and will not fail over to other servers in case of failure.
Proceed with fixed values and no DNS discovery? [no]: yes
Client hostname: node-01.ownyourlife.com.ng
Realm: COMPUTINGFORGEEKS.COM
DNS Domain: ownyourlife.com.ng
IPA Server: ipa.ownyourlife.com.ng
BaseDN: dc=learnhowto,dc=com

This will start configuring FreeIPA Client on your server:

Synchronizing time
No SRV records of NTP servers found and no NTP server or pool address was provided.
Using default chrony configuration.
Attempting to sync time with chronyc.
Time synchronization was successful.
User authorized to enroll computers: admin
Password for admin@COMPUTINGFORGEEKS.COM: 
Successfully retrieved CA cert
Subject: CN=Certificate Authority,O=COMPUTINGFORGEEKS.COM
Issuer: CN=Certificate Authority,O=COMPUTINGFORGEEKS.COM
Valid From: 2018-06-30 08:27:06
Valid Until: 2038-06-30 08:27:06

Enrolled in IPA realm COMPUTINGFORGEEKS.COM
Created /etc/ipa/default.conf
New SSSD config will be created
Configured sudoers in /etc/nsswitch.conf
Configured /etc/sssd/sssd.conf
Configured /etc/krb5.conf for IPA realm COMPUTINGFORGEEKS.COM
trying https://ipa.ownyourlife.com.ng/ipa/json
.......................

If everything went as expected, you should get a successful message like below:

The ipa-client-install command was successful

Step 4: Enable mkhomedir ( For Ubuntu only)

By default, sssd service will not create a home directory for the user on the first login, we need to enable this feature by modifying PAM configuration file.

sudo bash -c "cat > /usr/share/pam-configs/mkhomedir" <<EOF
Name: activate mkhomedir
Default: yes
Priority: 900
Session-Type: Additional
Session:
required pam_mkhomedir.so umask=0022 skel=/etc/skel
EOF

Then run:

sudo pam-auth-update

Select <OK>

How To Configure FreeIPA Client on Ubuntu / CentOS 7 2

Ensure “activate mkhomedir” is selected, it should have [*]

How To Configure FreeIPA Client on Ubuntu / CentOS 7 3

Then Select <Ok> to save changes.

Step 4: Testing FreeIPA Client ( Ubuntu & CentOS 7)

Now that we have everything we need to be configured, let’ create test user account on FreeIPA Server and try ssh to the client with the added user account. You can add an account to FreeIPA server from UI or CLI

Add user account from CLI:

$ kinit admin
Password for admin@COMPUTINGFORGEEKS.COM:

Enter admin password when prompted. Confirm that you have an active ticket using the command:

$ klist 
Ticket cache: KEYRING:persistent:0:0
Default principal: admin@COMPUTINGFORGEEKS.COM

Valid starting Expires Service principal
06/30/2018 09:33:40 07/01/2018 09:33:37 krbtgt/COMPUTINGFORGEEKS.COM@COMPUTINGFORGEEKS.COM

Add user to FreeIPA:

Set default shell to /bin/bash for all accounts:

sudo ipa config-mod --defaultshell=/bin/bash

Create user

$ ipa user-add jmutai --first=Josphat 
--last=Mutai --email=jmutai@ownyourlife.com.ng --password
Password: 
Enter Password again to verify: 
-------------------
Added user "jmutai"
-------------------
User login: jmutai
First name: Josphat
Last name: Mutai
Full name: Josphat Mutai
Display name: Josphat Mutai
Initials: JM
Home directory: /home/jmutai
GECOS: Josphat Mutai
Login shell: /bin/bash
Principal name: jmutai@COMPUTINGFORGEEKS.COM
Principal alias: jmutai@COMPUTINGFORGEEKS.COM
Email address: jmutai@ownyourlife.com.ng
UID: 32200001
GID: 32200001
Password: True
Member of groups: ipausers
Kerberos keys available: True

root@node-01:~# id jmutai
uid=32200001(jmutai) gid=32200001(jmutai) groups=32200001(jmutai)

You can confirm the existence of a user with ID 32200001

root@node-01:~# ssh jmutai@localhost
The authenticity of host 'localhost (<no hostip for proxy command>)' can't be established.
ECDSA key fingerprint is SHA256:y4GzK0NLDHF+g8pKNstpPq0Z6Gui+4jq/0WjtqKf5CE.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'localhost' (ECDSA) to the list of known hosts.

Password: 
Password expired. Change your password now.
Current Password: 
New password: 
Retype new password: 
Creating directory '/home/jmutai'.
Welcome to Ubuntu 18.04 LTS (GNU/Linux 4.15.0-23-generic x86_64)

* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
System information as of Sat Jun 30 10:04:49 UTC 2018

jmutai@node-01:~$ id
uid=32200001(jmutai) gid=32200001(jmutai) groups=32200001(jmutai)

Add the user account to FreeIPA from UI:

To add an account on Web UI, login to FreeIPA web interface and navigate to:

Identity > Users > Active users > Add

How To Configure FreeIPA Client on Ubuntu / CentOS 7 4

Click Add button to add the user.

Enable Passwordless Authentication using Private Key

If you would like to authenticate to a server without a password, copy your Public key to FreeIPA Server:

How To Configure FreeIPA Client on Ubuntu / CentOS 7 5

How To Configure FreeIPA Client on Ubuntu / CentOS 7 6

Click the Add button under “SSH public keys“, paste your public key into the box and save.

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Learn how to – How To Configure FreeIPA Client on Ubuntu / CentOS 7