RHEL 8 New Features for Experienced Linux Administrators

Log in to serverb then become the root user.

[student@workstation ~]$ ssh root@serverb
[student@serverb ~]$ sudo -i
[root@serverb ~]# 

Create a new lab-profile Authselect profile based on the existing sssd profile.

[root@serverb ~]# authselect create-profile lab-profile \
> -b sssd --symlink-meta
New profile was created at /etc/authselect/custom/lab-profile

Identify the correct time zone for Suriname/South America.

[root@serverb ~]# tzselect
Please identify a location so that time zone rules can be set correctly.
Please select a continent, ocean, "coord", or "TZ".
 1) Africa
 2) Americas
...output omitted...
#? 2
Please select a country whose clocks agree with yours.
...output omitted...
 9) Brazil            27) Guyana             45) St Vincent
10) Canada            28) Haiti              46) Suriname
11) Caribbean NL      29) Honduras           47) Trinidad & Tobago
...output omitted...
#? 46

The following information has been given:

  Suriname

Therefore TZ='America/Paramaribo' will be used.
Selected time is now:	Tue Feb 19 18:51:03 -03 2019.
Universal Time is now:	Tue Feb 19 21:51:03 UTC 2019.
Is the above information OK?
1) Yes
2) No
#? 1

You can make this change permanent for yourself by appending the line
	TZ='America/Paramaribo'; export TZ
to the file '.profile' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you
can use the /usr/bin/tzselect command in shell scripts:
America/Paramaribo

Change the time zone to America/Paramaribo.

[root@serverb ~]# timedatectl set-timezone America/Paramaribo

Configure chronyd to synchronize the time on serverb with classroom.example.com. Edit /etc/chrony.conf to include the following configuration file excerpt:

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
# pool 2.rhel.pool.ntp.org iburst
server classroom.example.com iburst
...output omitted...

Restart and enable the chronyd service.

[root@serverb ~]# systemctl restart chronyd
[root@serverb ~]# systemctl enable chronyd

Enable NTP synchronization on serverb.

[root@serverb ~]# timedatectl set-ntp true

Verify the clock synchronization status.

[root@serverb ~]# timedatectl
...output omitted...
System clock synchronized: yes
...output omitted...

Confirm that classroom.example.com is the time source for clock synchronization on serverb.

[root@serverb ~]# chronyc sources -v
210 Number of sources = 1

  .-- Source mode  '^' = server, '=' = peer, '#' = local clock.
 / .- Source state '*' = current synced, '+' = combined , '-' = not combined,
| /   '?' = unreachable, 'x' = time may be in error, '~' = time too variable.
||                                                 .- xxxx [ yyyy ] +/- zzzz
||                                                /   xxxx = adjusted offset,
||         Log2(Polling interval) -.             |    yyyy = measured offset,
||                                  \            |    zzzz = estimated error.
||                                   |           |
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^* classroom.example.com         8   6    37    51   -25ns[-703us] +/-  128us

Use Yum to install Python 2.7 using the python27 module.

[root@serverb ~]# yum module install python27
...output omitted...
Is this ok [y/N]: y
...output omitted...

Verify that Python 2.7 is available.

[root@serverb ~]# python2 -V
Python 2.7.15

Use Yum to install Python 3.6 using the python36 module.

[root@serverb ~]# yum module install python36
...output omitted...
Is this ok [y/N]: y
...output omitted...

Verify that Python 3.6 is available.

[root@serverb ~]# python3 -V
Python 3.6.8

Use the alternatives command to point /usr/bin/python to /usr/bin/python3.

[root@serverb ~]# alternatives --config python
There are 3 programs which provide 'python'.

  Selection    Command
-----------------------------------------------
*+ 1           /usr/libexec/no-python
   2           /usr/bin/python2
   3           /usr/bin/python3

Enter to keep the current selection[+], or type selection number: 3

Verify that the python command uses Python 3.6.

[root@serverb ~]# python -V
Python 3.6.8

Log off from serverb.

[root@serverb ~]# exit
[student@serverb ~]$ exit
[student@workstation ~]$