Install and Configure FreeIPA Server on CentOS 8 / RHEL 8

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Welcome to our guide on how to install and configure FreeIPA server on RHEL 8 / CentOS 8. FreeIPA is a free and open source identity management tool sponsored by Red Hat and it is the upstream for the Red Hat Identity Manager(IdM). In this guide, we will discuss on how to install and configure FreeIPA Server on CentOS 8 / RHEL 8 Linux server.

For CentOS 7: How to Install FreeIPA Server on CentOS 7

FreeIPA Identity management system aims to provide an easy way of centrally managing Identity, Policy, and Audit for users and services. It is designed to provide an integrated identity management service for a wide range of clients, including Linux, Mac, and even Windows.

Benefits of using FreeIPA

  • Central Authentication Management – Centralized management of users, machines, and services within large Linux/Unix enterprise environments.
  • Fine-grained Access Control: Provides a clear method of defining access control policies to govern user identities and delegation of administrative tasks.
  • One Time Password (OTP): Provides a popular method for achieving two-factor authentication (2FA).
  • Direct Connect to Active Directory: You can retrieve information from Active Directory (AD) and join a domain or realm in a standard way.
  • Active Directory Cross-Realm Trust: As System Administrator, you can establish cross-forest Kerberos trusts with Microsoft Active Directory. This allows external Active Directory (AD) users convenient access to resources in the Identity Management domain.
  • Integrated Public Key Infrastructure (PKI) Service: This provides PKI services that sign and publish certificates for hosts and services, Certificate Revocation List (CRL) and OCSP services for software validating the published certificate, and an API to request, show, and find certificates.

Components of FreeIPA Server

FreeIPA Server is composed of the following Open Source Projects.

  • 389 Directory Server – Main data store and provides a full multi-master LDAPv3 directory infrastructure.
  • MIT Kerberos KDC – Provides Single-Sign-on authentication.
  • Dogtag Certificate System – Provides CA & RA for certificate management functions.
  • ISC Bind DNS server – for managing Domain names.
  • Web UI / ipa Command Line tool – Used to centrally manage access control, the delegation of administrative tasks and other network administration tasks.
  • NTP Server

FreeIPA Server installation requirements

  • Server with 4gb ram – I got failed installations for 1GB and 2GB RAM
  • Fresh installation of RHEL / CentOS 8 server
  • 2 vCPUs
  • Port 443 and 80 not used by another application
  • FQDN – Resolvable over the public or private DNS server
  • 10 GB Disk space

See my server details below.

$ free -h
              total        used        free      shared  buff/cache   available
Mem:          3.7Gi       185Mi       3.3Gi       8.0Mi       196Mi       3.3Gi
Swap:         2.0Gi          0B       2.0Gi


$ lscpu
 Architecture:        x86_64
 CPU op-mode(s):      32-bit, 64-bit
 Byte Order:          Little Endian
 CPU(s):              2
 On-line CPU(s) list: 0,1
 Thread(s) per core:  1
 Core(s) per socket:  1
 Socket(s):           2
 NUMA node(s):        1
 Vendor ID:           GenuineIntel
 CPU family:          6
 Model:               94
 Model name:          Intel Core Processor (Skylake, IBRS)
 Stepping:            3
 CPU MHz:             1800.000
 BogoMIPS:            3600.00
 Hypervisor vendor:   KVM
 Virtualization type: full
 L1d cache:           32K
 L1i cache:           32K
 L2 cache:            4096K
 L3 cache:            16384K
 NUMA node0 CPU(s):   0,1
 Flags:               fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology cpuid tsc_known_freq pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves arat umip

$ df -h | grep root
/dev/mapper/rhel-root   17G  2.3G   15G  14% /

The next section will discuss the steps you need to install and configure FreeIPA Server on RHEL / CentOS 8.

Step 1: Set timezone and hostname

You need to have correct timezone and hostname on your server before you can proceed. The FreeIPA server will also run NTP service and correct timezone will ensure you have correct time on the server.

Step 2: Install FreeIPA Server on RHEL 8 / CentOS 8

RHEL IdM is an integrated solution to provide centrally managed Identity (users, hosts, services), Authentication (SSO, 2FA), and Authorization (host access control, SELinux user roles, services).

I had failed installation with SELinux in enforcing mode, I recommend you set it to permissive or disabled.

sudo setenforce 0
sudo sed -i 's/^SELINUX=.*/SELINUX=permissive/g' /etc/selinux/config

FreeIPA Server and client packages are distributed through AppStream repository in RHEL / CentOS 8. You can check IdM modules available.

$ sudo yum module list idm
 Updating Subscription Management repositories.
 Updating Subscription Management repositories.
 Last metadata expiration check: 0:16:51 ago on Sat 29 Dec 2018 09:52:44 AM EAT.
 Red Hat Enterprise Linux 8 for x86_64 - AppStream Beta (RPMs)
 Name         Stream             Profiles                                          Summary
 idm          DL1                adtrust, client, dns, server, default [d]         The Red Hat Enterprise Linux Identity Management system module
 idm          client [d]         default [d]                                       RHEL IdM long term support client module
 Hint: [d]efault, [e]nabled, [x]disabled, [i]nstalled

From the output, you can see we have DL1 and client streams. For more information about the Server module, run:

sudo yum module info idm:DL1

Since this is FreeIPA Server installation, install DL1 stream and then freeipa-server.

sudo yum -y install @idm:DL1
sudo yum -y install freeipa-server

If you want to include DNS service, also install ipa-server-dns,  bind  and bind-dyndb-ldap:

sudo yum install ipa-server-dns bind-dyndb-ldap

Other streams used as dependencies by this installation are:

  • 389-ds
  • httpd
  • pki-core
  • pki-deps

Step 3: Setup IPA Server on RHEL / CentOS 8

The initial configuration of the FreeIPA server is interactive and you only need to answer a few questions and all the dirty work is done via a script. You will be asked to provide:

  • Integrated DNS – if your DNS zone and SRV records are properly set on your system, you may proceed by selecting the default value “no”.
  • Host name – by default obtained using reverse DNS
  • Domain name – by default based on the host name
  • Realm name – by default based on the host name
  • Password for Directory Manager – an administrator account for Directory Server
  • Password for IPA administrator – a superuser for the IdM Server

If you don’t have DNS server to resolve server hostname, modify /etc/hosts file to include hostname and IP address.

$ sudo vi /etc/hosts
192.168.122.198 ipa.example.com

Confirm

[[email protected] ~]$ ping -c 2 ipa.example.com
 PING ipa.example.com (192.168.122.198) 56(84) bytes of data.
 64 bytes from ipa.example.com (192.168.122.198): icmp_seq=1 ttl=64 time=0.040 ms
 64 bytes from ipa.example.com (192.168.122.198): icmp_seq=2 ttl=64 time=0.113 ms
 --- ipa.example.com ping statistics ---
 2 packets transmitted, 2 received, 0% packet loss, time 30ms
 rtt min/avg/max/mdev = 0.040/0.076/0.113/0.037 ms

Configure server hostname to match above name:

export HNAME="ipa.example.com"
sudo hostnamectl set-hostname $HNAME --static
sudo hostname $HNAME

Don’t forget to replace ipa.example.com with your Valid hostname.

Then run ipa-server-install command to configure IPA server. Run as a user with sudo privileges or as a root user.

sudo ipa-server-install

If you want to configure DNS service as well, include  –setup-dns  option:

sudo ipa-server-install --setup-dns

Sample output:

$ sudo ipa-server-install
 The log file for this installation can be found in /var/log/ipaserver-install.log
 This program will set up the IPA Server.
 Version 4.7.1
 This includes:
 Configure a stand-alone CA (dogtag) for certificate management
 Configure the NTP client (chronyd)
 Create and configure an instance of Directory Server
 Create and configure a Kerberos Key Distribution Center (KDC)
 Configure Apache (httpd)
 Configure the KDC to enable PKINIT 
 To accept the default shown in brackets, press the Enter key.
 Do you want to configure integrated DNS (BIND)? [no]: >
 Enter the fully qualified domain name of the computer
 on which you're setting up server software. Using the form
 .
 Example: master.example.com.
 Server host name [ipa.example.com]: 
 The domain name has been determined based on the host name.
 Please confirm the domain name [example.com]: 
 The kerberos protocol requires a Realm name to be defined.
 This is typically the domain name converted to uppercase.
 Please provide a realm name [EXAMPLE.COM]: 
 Certain directory server operations require an administrative user.
 This user is referred to as the Directory Manager and has full access
 to the Directory for system management tasks and will be added to the
 instance of directory server created for IPA.
 The password must be at least 8 characters long.
 Directory Manager password: 
 Password (confirm): 
 The IPA server requires an administrative user, named 'admin'.
 This user is a regular system account used for IPA server administration.
 IPA admin password: 
 Password (confirm): 
 The IPA Master Server will be configured with:
 Hostname:       ipa.example.com
 IP address(es): 192.168.122.198
 Domain name:    example.com
 Realm name:     EXAMPLE.COM
 The CA will be configured with:
 Subject DN:   CN=Certificate Authority,O=EXAMPLE.COM
 Subject base: O=EXAMPLE.COM
 Chaining:     self-signed
 Continue to configure the system with these values? [no]: yes
 The following operations may take some minutes to complete.
 Please wait until the prompt is returned.
.....

This will:

  • Configure a stand-alone CA (dogtag) for certificate management
  • Configure the NTP client (chronyd)
  • Create and configure an instance of Directory Server
  • Create and configure a Kerberos Key Distribution Center (KDC)
  • Configure Apache (httpd)
  • Configure the KDC to enable PKINIT

A successful installation should give output similar to below.

....
Restarting the KDC
Configuring client side components
This program will set up IPA client.
Version 4.7.1

Using existing certificate '/etc/ipa/ca.crt'.
Client hostname: ipa.example.com
Realm: EXAMPLE.COM
DNS Domain: example.com
IPA Server: ipa.example.com
BaseDN: dc=example,dc=com

Configured sudoers in /etc/nsswitch.conf
Configured /etc/sssd/sssd.conf
Systemwide CA database updated.
Adding SSH public key from /etc/ssh/ssh_host_ed25519_key.pub
Adding SSH public key from /etc/ssh/ssh_host_ecdsa_key.pub
Adding SSH public key from /etc/ssh/ssh_host_rsa_key.pub
Could not update DNS SSHFP records.
SSSD enabled
Configured /etc/openldap/ldap.conf
Configured /etc/ssh/ssh_config
Configured /etc/ssh/sshd_config
Configuring example.com as NIS domain.
Client configuration complete.
The ipa-client-install command was successful
Setup complete

Step 4: Configure Firewalld for FreeIPA

It is recommended to run firewall service and allow access to ports used by FreeIPA server services.

sudo firewall-cmd --add-service=http,https,dns,ntp,freeipa-ldap,freeipa-ldaps --permanent
sudo firewall-cmd --reload

Step 5: Access FreeIPA Web interface

Your FreeIPA server installation is ready. Access the web UI on https://ipa.example.com.

install-freeipa-server-rhel-centos-8-login-1024x500

Login with admin username and IPA admin password provided during installation.

install-freeipa-server-rhel-centos-8-dashboard-1024x263

FreeIPA Administrative dashboard should be presented to you. Administration of the FreeIPA server can be done from the web UI or from the command line.

install-freeipa-server-rhel-centos-add-users-1024x480

Step 6: Secure FreeIPA Server With Let’s Encrypt SSL

After installation we recommend using secure SSL on your FreeIPA Server. If running on a public instance follow our guide in the next link:

Step 7: Using FreeIPA CLI

To use ipa command, you need to first get a Kerberos ticket.

$ sudo kinit admin
Password for [email protected]:

Check ticket expiry information using klist.

$ sudo klist 
Ticket cache: KCM:0
Default principal: [email protected]
Valid starting       Expires              Service principal
03/24/2019 11:48:06  03/25/2019 11:48:04  krbtgt/[email protected]

Set user’s default shell to /bin/bash.

$ sudo ipa config-mod --defaultshell=/bin/bash 
   Maximum username length: 32
   Home directory base: /home
   Default shell: /bin/bash
   Default users group: ipausers
   Default e-mail domain: example.com
   Search time limit: 2
   Search size limit: 100
   User search fields: uid,givenname,sn,telephonenumber,ou,title
   Group search fields: cn,description
   Enable migration mode: FALSE
   Certificate Subject base: O=EXAMPLE.COM
   Password Expiration Notification (days): 4
   Password plugin features: AllowNThash, KDC:Disable Last Success
   SELinux user map order: guest_u:s0$xguest_u:s0$user_u:s0$staff_u:s0-s0:c0.c1023$unconfined_u:s0-s0:c0.c1023
   Default SELinux user: unconfined_u:s0-s0:c0.c1023
   Default PAC types: MS-PAC, nfs:NONE
   IPA masters: ipa.example.com
   IPA CA servers: ipa.example.com
   IPA CA renewal master: ipa.example.com
   IPA master capable of PKINIT: ipa.example.com

Test by adding a user account and listing accounts present:

$ sudo ipa user-add test \
  --first=Test --last=User \
  --email=[email protected] --password

Password: 
Enter Password again to verify: 
-------------------
 Added user "test"
-------------------
   User login: test
   First name: Test
   Last name: User
   Full name: Test User
   Display name: Test User
   Initials: TU
   Home directory: /home/test
   GECOS: Test User
   Login shell: /bin/bash
   Principal name: [email protected]
   Principal alias: [email protected]
   User password expiration: 20190324085532Z
   Email address: [email protected]
   UID: 1201400001
   GID: 1201400001
   Password: True
   Member of groups: ipausers
   Kerberos keys available: True

To list user accounts added, run:

$ sudo ipa user-find
---------------
2 users matched
---------------
  User login: admin
  Last name: Administrator
  Home directory: /home/admin
  Login shell: /bin/bash
  Principal alias: [email protected]
  UID: 1201400000
  GID: 1201400000
  Account disabled: False

  User login: test
  First name: Test
  Last name: User
  Home directory: /home/test
  Login shell: /bin/bash
  Principal name: [email protected]
  Principal alias: [email protected]
  Email address: [email protected]
  UID: 1201400001
  GID: 1201400001
  Account disabled: False
----------------------------
Number of entries returned 2
----------------------------

Try to login as testuser. On your first log in, you’ll be asked to change your password:

$ ssh [email protected]
Password: 
Password expired. Change your password now.
Current Password: 
New password: id
uid=1201400003(test1) gid=1201400003(test1) groups=1201400003(test1) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

Uninstall FreeIPA Server on RHEL / CentOS 8

To uninstall FreeIPA Server, run:

$ sudo ipa-server-install --uninstall
This is a NON REVERSIBLE operation and will delete all data and configuration!
It is highly recommended to take a backup of existing data and configuration using ipa-backup utility before proceeding.
Are you sure you want to continue with the uninstall procedure? [no]: yes

If this server is the last instance of CA, KRA, or DNSSEC master, uninstallation may result in data loss.

Are you sure you want to continue with the uninstall procedure? [no]: yes
Shutting down all IPA services
Unconfiguring CA
Unconfiguring web server
Unconfiguring krb5kdc
Unconfiguring kadmin
Unconfiguring directory server
.......

You have successfully installed FreeIPA Server on CentOS / RHEL 8. Next reading is on

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Ben Bennett - https://www.thetodaypost.net
A systems engineer with excellent skills in systems administration, cloud computing, systems deployment, virtualization, containers, and a certified ethical hacker.