Changes

:* '''Correctly install the CentOS 7 FULL INSTALL DVD''' (not LIVE DVD) on your removable hard disk. * '''Record installation characteristics of CentOS 7 FULL INSTALL''' in a chart (contained in lab2 logbook chart) to compare with other installation methods performed in lab2.

:* '''Verify correct settings''' prior to proceeding with host installation stages.

:* '''Obtain Linux server information after installation''' to create a software asset report for later access.

:* '''Disable Linux Kernel security enhancements''' to allow easier internal networking connections (to be reactivated in a later lab).

:* Observe that '''Bash Shell Scripts can automate routine tasks'''.

|width="40%"|{{Admon/tip|Online Hands-on Linux Tutorials (recommended)|The following online tutorial will allow you to practice Linux commands that you learned from ULI101as well as essential shell scripting skills. Login to your '''Matrix''' account, and issue the pathnames to run the online tutorial in Matrix:<br><ul><li>Using the vi Text Editor:<br>'''/home/murray.saul/vi-tutorial'''<br><li>Linux Basics:<br>'''/home/murray.saul/linux-basics'''</li><li>Shell Scripting - Part I (Scripting Basics):<br>'''/home/murray.saul/scripting-1'''</li></ul>|

For the next 3 investigations, you will learn how to install your Centos Full DVD onto your removable hard disk. You will customize your install to setup several separate partitions: <ul><li>'''/''' (The "root " partition)</li><li>'''/home''' (/Store regular user accounts), </home, li><li>'''/var/lib/libvirt/images ''' (to store virtual machine images to be created in lab2), and a </li><li>'''swap ''' partition. (Virtual Memory)</li></ul> Make certain to record your observations of this install in the comparison chart for '''c7host ''' in your lab2 logbook.

# Restart the '''Newer computer, and models''' are labelled '''press the function key F10, press ENTER, and specify the device to bootHP Z230''' (eg. DVD drive).:<br><br>'''NOTES:'''NOTE:<ul><li>If you are using the '''<u>newer</u>''' model, allow the computer to boot up (<u>without</u> pressing F10 key) to boot from DVD.</li><li>Refer to the comparison chart in lab2 lab logbook, and fill in various installation information for '''c7host''' while you perform the installation (such as time it took to perform a full install, installation options, etc).<br><br></li></ul>

<li value="56">Select Power on the option computer again, and after booting from the CD, select from the installation menu: '''Test this Media & Install Centos7'''. Your DVD will be checked for defects<br><br>Note: If you experience unreadable display after you boot into your installed system, you can redo the install, but select from the install menu: ''<u>Troubleshooting</u>'' and then select ''<u>Install in Basic Graphics Mode</u>''.<br><br></li> <li>If the check is successfulNext, you will be prompted for a language. In the first screen, select language '''English''' with subselection '''English-Canada''' and then click the '''Continue''' button on the bottom right-hand screen.</li>

<li>Configure the following installation settings from the ''Install Summary Screen'':<br><br><b>DATE & TIME:</b><ul><li>Click on the Map to select Toronto area (you may also select from the drop-down menu section)</li><li>Click the <b>DONE</b> button at the top-right left corner to finish and return to the Installation Summary screen.</li></ul><br><b>NETWORK & HOSTNAME:</b><ul><li>Select the default Ethernet connection and click the button on the top right-hand side to change the setting from <b>OFF</b> to <b>ON</b>.</li><li>At the bottom rightleft-hand corner type the hostname: <b>c7host</b> (all lowercase letters)</li><li>Review your settings, then click the <b>DONE</b> button at the top-right left corner to finish and return to the Installation Summary screen.</li></ul><br><b>SOFTWARE SELECTION:</b><ul><li>Select the software packages labelled: <b>Gnome Desktop</b></li><li>Click the <b>DONE</b> button at the top-right left corner to finish and return to the Installation Summary screen.</li></ul><br></li> <li>Although the Centos installtion program can provide suggestions on how to partition your hard disk, you will be customizing partitions for your hard disk. This custom partitioning is important since it will have consequences on future labs that you perform (especially for lab2!).<br><br>Proceed to '''Part 2''' to customize your partitions.</li>

#The manual partitioning screen should appear. Change the option '''New mount points will use the following partition scheme''' from '''LVM''' to '''<u>Standard Partition</u>''' (you will not be using LVM for your c7host machine).

#It is recommended to rescan <span style="background-color:yellow">Change the hard disks by clicking on option '''New mount points will use the rescan button following partition scheme''' from '''LVM''' to '''<u>Standard Partition</u>''' (loop symbolyou will not be using LVM for your c7host machine)</span>.

#We will now create the root (/) partition. '''Click on the add button (plus) sign'''.<br>#In the '''Add a New Mount Point''' screen, enter select '''/''' as the mount-point (either by typing or selecting from drop-down menu), and enter '''30720''' in for partition size and click '''Add Mount Point''' button.# You will return to the previous dialog box.<br><span style="background-color:yellow">For the '''/''' partition, change the file-system type from '''xfs''' to '''ext4''' and make certain that the Device Type is set to Standard Partition (<u>not</u> LVM). You need to repeat this procedure for the ''/home'' and ''/var/lib/libvirt/images partitions'' as well)</span>.

#Select Recheck each of the created partitions, and make certain that the file-system type is changed from set to ''ext4'xfs'and the Device Type is set to '' to Standard Partition''.#Finally, add a swap partition (Mount Point: swap) for '''ext416 GB'''.#Check that your partition settings are correct (you can ask your instructor or lab monitor to confirm), and then click '''Done ''' (possibly '''<u>twice</u>''') in order to proceed<br><br><span style="background-color:yellow">'''NOTE:''' If there is an error message associated with your created partitions, you may need to add a '''/boot/efi''' partition (as a new mount). The capacity should be: 2954MB (i.e.2,954 MB). Once finished, click '''Done'''.<span><br><br>#A Summary of Changes screen will appear to show the partitioning operations that will be created. Click the '''Accept Changes''' button and click '''Begin Installation''' in the Installation Summary screen to proceed with the installation.#Start timing your host machine installation.

#During the installation process, you will required to create a '''root password ''' (for administration access) and create a '''regular user account'''. Click on '''Root Password''' and enter your root password. Think of an appropriate password and record that password somewhere in case you forget! An indicator will appear to show you how secure your password is. Retype your root password and click '''Done''' (you may have to click Done <u>twice </u> if your password is not considered to be a strongpassword).#You need to create a regular user account. This account will be used to graphical log into your host machine. It is never recommended to graphically log into a graphical Linux/Unix system as root. It is better to log into a regualr regular user account, then run a command to login as root (you will learn how to do this later in this lab).#Click '''User Creation''' and enter your '''full name''', '''username''', and an appropriate '''password''' (and confirm password). Click '''Done''' to finish(click twice if password is not considered to be a strong password).#<span style="background-color:yellow">Remember to record this host installation information in the '''installation comparison chart ''' in the lab2logbook</span>.

#Click the Reboot button. Your DVD will <u>briefly </u> open in the DVD drive bay. Make certain to remove this installation DVD so that Centos will boot from your hard drive.#After the system reboots, a boot menu should briefly appear, then prompt the user to accept the License Information (this is only a one-time occurrence).<br> In order to accept the license agreement, issue the following keystrokes:<br><br>'''1''' followed by ENTER (to select the license agreement prompt<br>'''2''' followed by ENTER (to accept the license agreement)<br>'''c''' followed by ENTER (to save the selection)<br>'''c''' followed by ENTER (a second time to continue booting into the system)<br><br>#The system should then graphically prompt the user to login by clicking with their regular user account. Click on your '''regular user account name ''' and entering the '''enter your regular user password'''.<br><br>#The last phase of the installation process should now run:<ul><li>Click Accept to confirm you will abide by Confirm English as the License default input source and click Done'''Next'''.</li><li>Accept defaults to participate running KDump application that will report errors to developers for improvements to Centos7Skip the creation of online accounts by clicking '''Next'''.</li>Start using your installed Linux system by clicking '''Start Using CentOS Linux'''.</li>Select English as the default input source.</liul><libr>Quickly view Getting Started Resources, then close #Stop timing your installation and note the amount of time that your installation took to perform. Also take the time to fill in the c7host section of the installation comparison chart in your lab2 logbook.#Open a web-browser and check to see if you can connect to the help windowInternet.</libr></ulbr> === Turn-Off Screen Saver Lock === :Your system automatically enables a '''screen-saver''' application which is a useful security tool to prevent unauthorized viewing of information on a terminal after a certain amount of inactivity. :If you find this feature annoying and want to turn it off or adjust the idle time perform the following steps::*Click on your '''username at the top right-hand screen''':*Select '''Settings''' from the drop-down menu.:*Click the '''Power''' icon located in the ''Settings'' Dialog Box:*Change the amount of time in the '''Power Saving''' section to '''Never''' or a '''longer period of time''':*Close the ''Settings'' Dialog box.  <ol><brli value="14">#Proceed to Investigation 2 to obtain basic information from your newly installed Centos Host machine.</li></ol>

#Issue the following With older (ancient) versions of Linux, a user once may have been allowed to login to their graphical Linux command: <b><code><span style="color:#3366CC;fontsystem using '''root''' as their user-size:1name and their root password.2em;">login root</span></code></b>#Issue This has been determined to be a security risk and that option has been removed with many or all Linux command (learned in ULI101) to confirm the type of account you are currently usingoperating systems. What is the purpose of this account?#Exit Therefore, from this point onwards, you will be logging into your current regular user accountinstead and issuing a command to login as the ''root'' user. Which account are you now using?

#Issue the command <b><code><span style="color:#3366CC;font-size:1.3em;">su - </span></code></b> Issue the '''pwd''' and '''whoami''' commands to confirm your directory pathname. Remain in this account for What do you notice are the remainder of this lab.main differences between using '''su''' versus using '''su -''' ?# An installation log file called <b><code><span style="color:#3366CC;font-size:1.2em;">/var/log/anaconda/anaconda.packaging.log</span></code></b> has been created to record the installation of your c7host machine. This file is an ASCII file which can be viewed with the <b><code><span style="color:#3366CC;font-size:1.2em;">more</span></code></b> command.

:: <b><code><span style="color:#3366CC;font-size:1.2em;">grep ________________ ________________ -i packaging /var/log/anaconda/packaging.log | wc -l'''</span></code></b>

<li value="98">Issue that command displayed above. Does it work? If not, what account do you think you should be in? When you get the command working record this important information regarding commands and the admin account in your lab logbook.</li> <li>Using the <code>rpm</code> command: you can also use the following commands to list all the installed packages, and the total number of packages installed:</li>

<li>Some of the files on your system were installed with the software packages, and some were created by system activity (for example, by creating your Learn account and by logging in). If you know the package name (from the <code>installpackaging.log</code>), you can list all the files that were installed from the package by using the following command:</li>

::<b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">rpm -q -l package_namegedit</span></code></b> (where  <ol><li value="package_name12" represents >Issue the following command to obtain the name total number of the ''application'' or ''package'')files installed for gedit:<br><br></li></ol>::<b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">rpm -ql gedit | wc -l</span></code></b>

<li value="12">This combines the <code>'''-q'''</code> (query) option with the <code>'''-l'''</code> (list filenames) option</li> <li>You can pipe the outupt through <code>'''wc -l'''</code> to count the number of lines:</li></ol>::<b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">rpm -ql package_name| wc -l</span></code></b><ol> <li value="1413">Using what you learned in steps 3, 4, and 7, get a count of the total number of files installed by all of the software packages on your system.</li><li>How can you explain why this number is a lot larger than the total number of packages installed? Record your answer in your lab logbook.

#We will now collect networking information for your installed system. Your system may not be automatically connected to Seneca's network. Locate the network icon (on top right-hand panel). Click on that icon, and select: '''system eth0'''# Open a web-browser and log into Seneca's wired network. You will need to perform this set every time you start a new session with your computer to perform future labs.#Open a shell terminal.

:::<b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">nslookup</span></code></b> (at the > ''nslookup'' prompt, enter the word "'''server" (do not type the quotes) ''' and record the output. Type exit to leave nslookup).

<ol><li value="9">Run the commands <b><code><span style="color:#3366CC;font-size:1.2em;">hostname</span></code></b>, <b><code><span style="color:#3366CC;font-size:1.2em;">uname -rv</span></code></b>, <b><code><span style="color:#3366CC;font-size:1.2em;">ps -ef</span></code></b>, <b><code><span style="color:#3366CC;font-size:1.2em;">ifconfig</span></code></b>, and <b><code><span style="color:#3366CC;font-size:1.2em;">route -n</span></code></b> redirecting the output to add to a file in root's home directory called <b><code><span style="color:#3366CC;font-size:1.2em;">system.txt</span></code></b>.</li><li>Copy the installation log file <code>'''/var/log/anaconda/anaconda.packaging.log'''</code> and the file '''system.txt''' to a USB memory key, or '''scp''' to your matrix account as a backup.</li></ol>

# Disabling SELinux is quite simple, just edit the file '''/etc/selinux/config''' and set SELINUX to disabled'''disable<u>d</u>'''.

{{Admon/tip|Bash Shell Scripting Tips:|<br><ul><li>'''She-bang line: #!/bin/bash'''<br><br>Shell scripts have evolved of the past 40 years. To avoid running a newer shell script on an older shell, it is recommended to force running the shell script in the correct shell. In order to do this, on the first line at the very beginning of the shell script, you add the '''#!''' ('''# as in "shhhh" - a comment''', and''' ! is referred to as "bang" run a commmand''': in this case, '''run the command: /bin/bash'''). You can issue the Linux command '''which bash''' to get the correct location. If there is no bash shell on that machine, the shell script will not run (as a precaution - the Linux admin will know how to make a fix to the shell script if required).<br>. </li><li>'''Variables:'''<br><br> There are 3 types of variables that can be used in shell scripting: '''ENVIRONMENT''' (eg. $USER), '''user-defined''' ($varName), and '''positional parameters''' (eg. $1, $2... containing arguments after shell script or by using set command (eg. '''set $(ls)''' ). Using dollar sign ('''$''') in front of variable expands the value assigned.<br><br></li><li>'''Command Substitution:'''<br><br>A very useful trick to take output from a command to be used as an argument for another command. Examples include:<br>'''file $(ls)'''<br>'''set $(ls);echo $#;echo $*'''<br>'''echo "hostname: $(hostname)"'''<br><br><li>'''Logic Control Flow Statements:'''<br><br>The '''test''' command can be used to see if a condition is true or false<br>(i.e. test $USER &#61; "root") . The '''$?''' special shell variable stores the result (zero if true, non-zero if false). Square brackets '''[ ]''' can be used to represent the test command with the condition <u>inside</u> the brackets (spaces separating brackets).Can use '''if''' / '''if-else''' / '''if-elif-else''' statements with brackets. The '''exit''' command can be used to terminate the shell script with a false value.<br><br>'''<u>Examples</u>'''<br><br>''if [ $USER &#61; "root" ]''<br>''then''<br>&nbsp;''echo "You must be root" >&amp;2''<br>&nbsp;''exit1''<br>''fi''<br><br># For number comparison: use:<br># -gt,-ge, -lt, -le, -eq, -ne<br><br>''if [ $age -gt 65 ]''<br>''then''<br>&nbsp;''echo "retire"''<br>''else''<br>&nbsp;''echo "don't retire"''<br>''fi''<br><br>''if [ $grade -gt 79 ]''<br>''then''<br>&nbsp;''echo "You get Good Mark"''<br>''elif [ $grade -gt 49 ]''<br>''then''<br>&nbsp;''echo "You pass"''<br>''else''<br>&nbsp;''echo "You fail"''<br>''fi''<br></li></ul>}}

You may have learned about creating and running Bash Shell Scripts in your ULI101 course. Shell scripts help Linux users and system administrators to automatic automate repetitive tasks to become more efficient and to help them save time. You will be reviewing and building a basic Bash Shell script to generate information reports for your newly-installed Linux host machine. Take time to view Shell Scripting Tips which are located on the right-hand side. If you require <u>'''additional practice'''</u> in creating shell scripts and using the vi text editor, and run the online commands in your '''Matrix''' account: <ul><li>'''/home/murray.saul/vi-tutorial to learn how to create simple shell scripts'''</li><li>'''/home/murray.saul/scripting-1'''</li></ul> Perform the following steps in your '''c7host''' machine:

<ol><li value="4">Save your editing session, assign your reportthe '''myreport.bash ''' file read and execute permissions (at least for the owner) and run by typing: <br><b><code><span style="color:#3366CC;font-size:1.2em;">./myreport.bash</span></code></b></li><li>Did it run? If not what do you think you need to do in order to run the Bash Shell Script?</li><li>Issue the command <b><code><span style="color:#3366CC;font-size:1.2em;">su-</span></code></b> and run the Bash shell againscript from the regular user's home directory (not root's home directory):<br><b><code><span style="color:#3366CC;font-size:1.2em;">~regularuserid/myreport. bash</span></code></b></li><li> Did it work?</li><li>Reopen your text-editing session for '''~regularuserid/myreport.bash ''' and add the following lines of code to the bottom of the shell script file:</ol>

<ol><li value="8">Save and run the bash shell script. View the contents of the file called "'''report.txt" ''' that was generated (I hope you are using the up arrow key to issue previously issued commands in order to save time!). Notice how the redirection symbol &gt; is used at the beginning of the report, and then the other redirection symbol &gt;&gt; is used to help "grow" the report with the other content.</li><li>The only remaining content of the report would be the system information. We can use a shell scripting trick called "command substitution" $( .. ) in order place results from an command to be used by another command (like echo). Re-edit the shell script and add the following code at the bottom of the shell script file:</li></ol>

<ol><li value="10">Save, run the script, and view the resulting file ''report.txt'' contents (are you using tip that was given to save time?).</li><li>Edit the shell script and include output from the <b><code><span style="color:#3366CC;font-size:1.2em;">ps aux</span></code></b> and <b><code><span style="color:#3366CC;font-size:1.2em;">ifconfig</span></code></b> commands (with appropriate titles). Remember to redirect that output to add to the bottom of the file!</li><li>Save, run and confirm that the shell script is working correctly.</li><li>What would be the use of keeping this shell script as a Linux system administrator?</li></ol><ol><li value="14">Here are some more "complex" Bash Shell scripts, that perform the same task. Although you are not require to understand some of these other tricks, it is recommended that you view the contents of the scripts and save them for future consideration or exmaples.</li><li>The <b><code>wget</code></b> command can be used to quickly download files from the Internet. Issue the following command:<br><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">wget https://scs.senecac.on.ca/~murray.saul/text-report.bash</span></code></b></li><li>Verify that the file '''text-report.bash''' was downloaded to your current directory.</li><li>Assign read and execute permissions for this file by issuing the command: <b><code><span style="color:#3366CC;font-size:1.2em;">chmod u+rx text-report.bash</span></code></b></li><li>Run this Bash Shell script by issuing the command: <b><b><code><span style="color:#3366CC;font-size:1.2em;">./text-report.bash</span></code></b></li><li>Check to see if it created a report in your current directory. What is the purpose of the report?</li><li>Use the <b>vi</b> text editor to view the contents of the file <b>text-report.bash</b>. Can you understand how this script works?<br><br></li><li>Use the <b><code>wget</code></b> command to download, study, and run the following shell scripts on-line:<blockquote><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">https://scs.senecac.on.ca/~murray.saul/report.bash<br>https://scs.senecac.on.ca/~murray.saul/report3.bash</span></code></b></blockquote></li><li>Try to understand what these Bash Shell scripts do.</li><li>You have completed lab1. Proceed to Completing The Lab, and follow the instructions for "lab sign-off".</li></ol>

[[Image:lab1_signoff.png|thumb|right|500px|Students should be prepared with a'''ll all required commands (system information) displayed in a terminal (or multiple terminals) prior to calling the instructor for signoff'''.]]

::<span style="color:green;font-size:1.5em;">&#x2713;</span> Contents of your '''reportmyreport.bash''' shell script::<span style="color:green;font-size:1.5em;">&#x2713;</span> proof of '''yum update''' performed on c7host::<span style="color:green;font-size:1.5em;">&#x2713;</span> '''SELinux''' is disabled on '''c7host'''

= ADDITIONAL PRACTICE = Practice For Quizzes, Tests, Midterm &amp; Final Exam ==

# List 3 2 ways that you can access your root account