Featured

Linux Cloud Technologies 2013

  Build the cloud on Linux!  This year looks very promising for Linux when it comes to building your private cloud using open source technologies.  Finally, Linux-based software and application

Read More
Linux Cloud Technologies 2013

Join CentOS 6 to Active Directory Domain

11
by on October 1, 2013 at 4:03 pm

Joining CentOS 6 or Red Hat Enterprise Linux 6 to an Active Directory Domain is relatively simple.  While Active Directory is proprietary software developed by Microsoft, it’s fairly ubiquitous in medium and large environments, thus integrating Linux and Windows services is very common in this day and age.  DNS has to be working properly.  You should be able to resolve mydomain.com using DNS.

First, we need to install winbind.  This is the Samba service that integrates users, passwords, and other important functions with Active Directory.

yum install samba-winbind

That command should install any and all dependencies necessary.  Another step is to install software necessary for initializing Kerberos tickets.  While not strictly necessary to join the Domain initially (I believe), it makes troubleshooting a little easier.

yum install krb5-workstation

After those two packages are installed, you can run authconfig-tui to automatically setup pam and other important config files.  See the screen shots below for example settings.

authconfig-tui

The above selections are appropriate.  Use fingerprint reader is not needed unless your workstation has a fingerprint reader.

authconfig-tui

This stage is very important.  Security model should be set to ADS.  Domain should be the name of the domain without the top level domain.  If your domain looks like my.domain.com, then you should put “MY” in this field.  Domain controllers are the FQDN for each domain controller you wish your system to use.  Unlike Windows, these are not automatically discovered by CentOS or RHEL 6.  Separate each domain controller by a space.  ADS REALM should be the full name of your Domain in ALL CAPS.  Template shell can be whichever you choose.  If you want to enable domain users the ability to log in by default, select one of the shells.  If you want to disable ssh/local login by default, select /sbin/nologin.

Next, select Join Domain and enter your Domain Admin username and password in the boxes provided.  You should enter just the username, do not enter any domain information here.

, , , , ,

How to RDP from CentOS 6 using Network Level Auth

0
by on October 1, 2013 at 3:22 pm

Connecting from CentOS 6 to Windows Server 2008 R2 used to be impossible if you had Network Level Authentication required on your Windows Servers. However, the latest version of rdesktop (1.8 as of this writing) finally integrates NLA. Unfortunately, if you’re using CentOS 6 or Red Hat Enterprise Linux 6, the newest version is not currently available from the EPEL or base repos.   In this article I’m going to show you how to build and install the software so it works correctly.

(more…)

in CentOS, How-To, Red Hat

, , , , , ,

Ad goes here

Join Fedora 19 to Active Directory Domain using realmd

18
by on September 23, 2013 at 4:24 pm

For years, Linux administrators have been successfully using Samba winbind to integrate Linux with Active directory.  While configuring a Linux host to join an Active Directory Domain is pretty simple, it still involves editing a few configuration files manually in most cases.  The new software, realmd, changes all of that, and makes joining a Linux host to an Active Directory Domain easier than ever before!

(more…)

, ,

Install OpenStack Grizzly on Fedora 19 with Quantum Networking

0
by on August 14, 2013 at 7:35 pm

I recently registered for an watched a Red Hat online seminar, Taste of Training for the upcoming Red Hat Open Stack course.  Up until very recently, Red Hat OpenStack was only a technology preview, but now Red Hat is offering full support for OpenStack as part of it’s Red Hat Cloud Infrastructure product suite.

If you’re already familiar with OpenStack and/or Fedora, you can refer to this ’3 step’ guide from Red Hat:  http://openstack.redhat.com/Quickstart  Since you’re using Fedora 19, you’re not likely going to actually be able to complete the install in 3 steps as the guide suggests.  I have found there are numerous steps that must/should be modified for a smooth installation, and I have compiled those steps here for my readers.

What I’m going to outline here are some of the necessary tips and methods I gleaned from hours of frustration.  I also hope to include pretty screen shots for your convenience :).

I also intend to use Quantum networking, and (coming soon) GlusterFS as cinder storage.

(more…)

, , , , , , ,

SQL Server insert with sub queries

0
by on July 9, 2013 at 1:51 pm

Extremely awesome SQL query I wrote.


use my_db

INSERT INTO
 dbo.my_archive

select
ltrim(rtrim(str(b.my_id)))+ltrim(rtrim(str(b.date))) pid_date,
b.my_id,
b.date,
p.column1+p.column2 ssdd,
p.last_name,
p.first_name,
COUNT (*) Amount,
(
select COUNT(*) from amounts b1
where b1.flags = '1'
and b1.my_id = b.my_id
and b1.date = b.date
) Deleted,
(
select SUM(m.count1)
from mail_counts m
where m.my_id = b.my_id
and m.date = b.date
) Counts

 from amounts b

inner join pusers p
on b.my_id = p.my_id

where (b.date < '20130701' and b.date >= '20120101')
and not exists (
select *
FROM dbo.my_archive mt
where mt.pid_date = ltrim(rtrim(str(b.my_id)))+ltrim(rtrim(str(b.date)))
)
and p.column1 != 'TS'

group by b.date, b.my_id, p.first_name, p.last_name, p.column1+p.column2

in Uncategorized

,

Connect to SQL Server with Python

0
by on July 5, 2013 at 2:23 pm

Recently I was tasked to rewrite some Perl cgi scripts.  My time is valuable to me, so I rewrote them in Python!  One of the functions of the cgi scripts was to connect to a Microsoft SQL Server 2008 r2 instance.  A quick glance at the perl scripts showed me we were using ODBC to connect to SQL Server.  After a few hours of reading online, I settled upon what I believe is the best method, using pyodbc.

pyodbc is an open source library for python, available at https://code.google.com/p/pyodbc/  Installation is pretty straight forward, but I will outline the steps here and help you connect to SQL Server as well.

(more…)

in How-To, Red Hat

, , , ,

Ajax script with python backend

0
by on June 10, 2013 at 3:07 pm

At my day job, I’m a Linux System Administrator.  This roughly translates to “Everything System Administrator” as I work in a lot of other capacities as well.  One of my duties is maintaining an internal web portal that runs on a RHEL 6 system.  A good portion of our portal runs on Python and Perl CGI scripts.  I wanted to dynamically update part of a page and I needed to make an Ajax call to a Python script instead of a normal PHP or ASP (etc).  I ran into a problem with a not so obvious solution compared to how people make calls to PHP backends.

(more…)

in How-To

, , , , ,

Centos 6 Apache Kerberos AD SSO

14
by on May 21, 2013 at 7:22 pm

I recently setup a RHEL / Centos 6 Apache websever at work that integrates with Active Directory (AD) and Kerberos for a single sign on (SSO) web resource.  This took me a lot more time than I thought it would, but that’s because the tutorials I was reading were either wrong, or didn’t apply to my situation.  I am outlining the steps I took below to help others who may wish to have a similar setup.

(more…)

in CentOS, How-To, Red Hat

, , , , , , ,

Install vSphere CLI in CentOS 6

0
by on May 7, 2013 at 4:04 pm

I recently installed VMware’s vSphere CLI 5.1 tools on a CentOS 6 x86_64 VM.  Despite the rather reassuring documentation released by VMware, installing these tools was no simple task.  I will outline the steps that I took for a successful installation of the vSphere CLI software, as some of it is not very obvious, especially for beginners.

(more…)

, , , ,

Top 10 useful linux cli tools

3
by on April 11, 2013 at 3:42 pm

Here are some tools I use on a fairly frequent basis, which may or may not be installed by default in your distribution.  I highly recommend installing these tools during the provisioning stage of your system/environment because repositories aren’t always reachable on production systems.  Furthermore, installing software on a running critical production system is often a tightly controlled process.

(more…)

in Uncategorized

Categories