1. Review Security Hardening IPTables SELinux

2. Today Installations and updates – Rpm command and packages Apache “Issue Ownership”

3. Installing Items Several Different Ways – Build from source works on all systems – Download source code, unzip it, run ‘make file’ – Compiles it on your system – Annoying, time consuming, etc… Different distributions have ‘package managers’ – Debian/Ubuntu – Apt-Get / dpkg – SuSE - YaST

4. CentOS/RHEL Online (aka, requires internet connection) – yum – yum install # or update or…. – VERY easy, very nice, I highly recommend it Offline (aka, no internet connection) – Must know package name – rpm (RedHat Package Manager) – Flags will then lead us to install, uninstall, update, etc…

5. RPM Usage Simple installation – rpm -i – rpm -ivh List installed programs – rpm -qa #optional: Uninstall program – rpm -ev Notice difference between filename and package

6. RPM File Names An RPM filename will end in.rpm The name will usually contain package, version, OS version, and architecture CentOS 6 Apache installation file httpd-2.2.15-26.el6.x86_64.rpm – Package: httpd – Apache version: 2.2.15-26 – OS version: ‘Enterprise Linux’ 6 (el6) – Architecture: x86_64 (Intel, 64-bit)

7. Complex Installations Some packages will require a ‘depdency’ A dependency is another install package – Possibly another program, possibly a library For example, to run the GNU C++ Compiler (g++), you have to have the GNU C Compiler installed (gcc) g++ has a dependency of gcc rpm -R

8. Failures Dependencies 2 packages, 2 libraries Packages will most likely appear with that name Libraries will have to be Google’d for

9. Library Packages libapr-1.so.0 – library package In an offline install this will not show up as libapr.rpm or any variation

10. Libapr-1.so.0 Easily handled - apr package and apr-util packages contain the libapr and libapr-util libraries Go through each dependency from the top, install all the ones you can easily Then try to install the main packages and Google anything left over

11. Successful Install rpm -ivh apr-util-1.3.9-3.el6_0.1.x86_64.rpm

12. So We Can Use It We can see it in the output of rpm -qa httpd Even more, we can use it

13. What Is A Web Server? “The hardware or software that delivers web content” –wikipedia Thanks, wikipedia, that’s helpful Web server is a computer running – Windows OS & IIS application – Linux OS & Apache application – There are others, those are the big ones They hold the code files that make up web pages (facebook, Amazon, ESPN, etc…)

14. Apache Web Server “LAMP Stack” – Linux, Apache, MySQL, PHP – Everything you need to build a ‘feature-rich’ website (ESPN.com) Config file in /etc/httpd/conf/httpd.conf Contains ‘modules’ that help develop web site Code files in /var/www – Expected to be ‘feature rich’

15. Apache Details Service named httpd (so we can control it by the services command & see it in ps) – What would that command be? Starts about 8 processes named httpd Sits “on top” of our networking scripts, opens port 80 to “listen” for incoming web (http) connections, etc…

16. Apache Config So when we browse to the IP

17. Quick Aside – Regular Tasks Starting out in IT, expect: Programmers: documenting code – Possibly minor bug fixes Networking: monitoring – I actually know the least about what entry-level networking is Sysadmin: Password resets, low-level user calls – Aka, help desk

18. Help Desk Help desk isn’t a bad place to be But it’s hard to move out into ‘sysadmin’ work – Easier to move up to L2/L3 support – Internships are the way to go Regardless, you’ll usually have a ‘script’

19. Help Desk In that script you won’t have too much freedom, which means you won’t have too much opportunity to show off skills Sometimes you do, and sticking with something (especially the really annoying things) are what managers look for They call it “issue ownership” – Do you take the next step when it’s not in your script?

20. Example Apache is not installed on our VM’s

21. Or You Might Get A Ticket “User X Can’t Log In” – Login to what?! – Obviously not the ticketing system This is why I structure our class this way – This is also the least-favorite assignment of many students “Scope” the problem Outline the fix Implement Write-up

22. Your Homework and Practical Install Apache on our vm’s – Using rpm, not using yum Turn in a short write-up of what you did and how Documentation is necessary – 1) tells you where you are – 2) tells you what you’re doing – 3) covers your behind

23. Tickets IDS was owned by ‘Enterasys’ (now Dell) Awful support, except for 2/3 guys Used their tickets to show their mgmt they weren’t responding (many times) Got 2 of the “good” responders dedicated to our account I’m sure they were chewed out after the 4 th /5 th /6 th time we escalated through our mgmt

24. Own Study Installations and updates – Rpm command and packages – http://www.thegeekstuff.com/2010/07/rpm- command-examples/ http://www.thegeekstuff.com/2010/07/rpm- command-examples/ Apache – http://www.centos.org/docs/5/html/Cluster_Adm inistration/s1-apache-inshttpd-CA.html http://www.centos.org/docs/5/html/Cluster_Adm inistration/s1-apache-inshttpd-CA.html