#REDIRECT [[OPS235_Lab_1_-_CentOS7_-_SSD2]]
[[Category:OPS235]]
=LAB PREPARATION=
[[Image:vmware-1a-alt.png|thumb|right|550px|If you have a removable hard drive (as opposed to a solid state drive), you will be creating a Linux host machine first to support virtual machines that you will create later in lab 2. ]]
===Purpose of Lab 1===
In order to save money and resources when learning to install, to manage, and to connect Linux machines to form networks, we will be using '''Virtual Machines''' for this course.
:*'''lab1:''' Create a Centos7 Host machine ('''c7host''') on your removable hard drive.
:*'''Lab2:''' Install a Virtual package on your host machine called '''KVM''' which will be used to create 3 remaining Virtual Machines (VMs) that will be used to learn about Linux system administration for the remainder of this course.
It is ESSENTIAL to have a '''removable hard drive with a minimum storage capacity of 240 GB''' to perform your lab sessions and provide a host for your other Centos7 host and other VMs that you will create in lab2. '''Due to space requirements, you are <u>NOT</u> permitted to share this removable hard drive with any other course material than our OPS235 course'''.
<span style="font-size:16px;font-weight:bold">Main Objectives<br></span>
* '''Correctly install the CentOS 7 FULL INSTALL DVD (c7host)''' on your removable hard drive.
* Note common Linux commands and record them in your lab1 logbook.
* Use '''Shell scripts''' to generate a post-install report for your Centos7 host VM.
* '''Disable Linux Kernel security enhancements''' to allow easier internal networking connections (to be reactivated in a later lab).
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|colspan="3" style="font-size:16px;font-weight:bold;border-bottom: thin solid black;border-spacing:0px;"|Minimum Required Materials<br>
|colspan="3" style="font-size:16px;font-weight:bold;border-bottom: thin solid black;border-spacing:0px;padding-left:15px;"|Linux Command Reference<br>
|- valign="top" style="padding-left:15px;"
| [[Image:blank-cd.png|thumb|left|75px|<b>CentOS7</b>FULL INSTALL DVD]]
| [[Image:harddrive.png|thumb|left|75px|<b>Removable SATA Hard Disk</b>]]
| [[Image:log-book.png|thumb|left|70px|<b>Lab Log Book</b><br>(lab 1)]]
| style="padding-left:15px;" |Package Management
[https://linux.die.net/man/8/rpm rpm]<br>
[http://man7.org/linux/man-pages/man8/yum.8.html yum]<br>
System Information<br>
[http://man7.org/linux/man-pages/man1/hostname.1.html hostname]<br>
[http://man7.org/linux/man-pages/man1/uname.1.html uname]<br>
[http://man7.org/linux/man-pages/man1/ps.1.html ps]<br>
[http://man7.org/linux/man-pages/man8/lsblk.8.html lsblk]<br>
Networking<br>
[http://man7.org/linux/man-pages/man8/ifconfig.8.html ifconfig]<br>
[http://man7.org/linux/man-pages/man8/route.8.html route]<br>
[http://linux.math.tifr.res.in/manuals/man/nslookup.html nslookup]<br>
| style="padding-left:15px;"|Miscellaneous
[http://man7.org/linux/man-pages/man1/grep.1.html grep]<br>
[http://man7.org/linux/man-pages/man1/wc.1.html wc]<br>
[http://man7.org/linux/man-pages/man1/pwd.1.html pwd]<br>
[http://man7.org/linux/man-pages/man1/ls.1.html ls]<br>
[http://man7.org/linux/man-pages/man1/more.1.html more]<br>
[http://man7.org/linux/man-pages/man1/file.1.html file]<br>
[http://man7.org/linux/man-pages/man1/wget.1.html wget]<br>
[http://man7.org/linux/man-pages/man1/chmod.1.html chmod]<br>
[https://ss64.com/vi.html vi]
| style="padding-left:15px;"|Matrix on-line tutorials<br><ul><li>Linux Basics:<br>'''/home/murray.saul/linux-basics'''</li><li>Using the vi Text Editor:<br>'''/home/murray.saul/vi-tutorial'''</li><li>Shell Scripting - Part I (Scripting Basics):<br>'''/home/murray.saul/scripting-1'''</li></ul>
|}
=INVESTIGATION 1: CREATE AND INSTALL HOST MACHINE (c7host)=
In this lab, you will learn how to install your '''Centos Full Install DVD''' as a host machine.
Make certain to record your observations in your '''lab1 logbook'''.
===Part 1: Using KVM to Create a New Virtual Machine (VM) ===
'''<u>c7host Machine Details:</u>'''
*'''Name:''' c7host
*'''Boot media / Installation:''' CentOS7 Full Install DVD
:::*Download at Seneca College: CentOS 7 Full Install DVD (image file): http://mirror.csclub.uwaterloo.ca/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-1708.iso
:::*Download outside Seneca College: http://mirror.csclub.uwaterloo.ca/centos/7/isos/x86_64/CentOS-7-x86_64-DVD-1708.iso
*'''Disk space:''' 240GB
*'''CPUs:''' 1
'''Perform the following steps:'''
[[Image:installation_summary.png|thumb|right|400px|The '''Installation Summary''' screen provides flexibly when configuring to install on your computer. ]]
# Although the images may be a little out of date (i.e. not exact), you can refer to this listing of installation screenshots for general reference:<br>[[http://matrix.senecac.on.ca/~murray.saul/ops235/ssd2/ installation screen-shots] ]<br>
# Insert your '''removable SATA hard disk''' into the drive tray.
# Set your computer's drive selector switch to '''external''' (a.k.a ''position #4'').
# Power up the computer and insert the '''CentOS 7 Installation DVD''' into the DVD drive, then power-off computer.
<ol> <li value="5">Power on the computer again, press the '''F9''' key a few times upon boot, and select '''SATA5''' near the bottom on the menu to boot from your DVD. After booting from the DVD, select from the installation menu: '''Install Centos7'''.<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>Next, 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>The '''Install Summary''' should now appear. This screen allows the installer to customize their Centos7 system prior to installation.</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-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 left-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-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-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>
</ol>
===Part 2: Creating Partitions ===
The next step is to perform a custom installation for your Centos7 virtual machine using the Centos7 Full DVD. Upon creation of your c7host virtual machine, The VMware Workstation application will automatically simulate a "boot" to allow you to complete the installation process to create the Centos7 operating system on that virtual machine.
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{{Admon/note|Mount Points and Linux File System Types|Similar to other Operating Systems like windows '''fat''' / '''vfat''' / '''ntfs''' file system types, it is good to know a few common file system types in Linux for comparison:<br><ul><li><b>xfs:</b> Newer filesystem (fast transfer rates for large files, Journaling)</li><li><b>ext4:</b> Newer filesystem supporting large files and Journaling (used in for this lab)</li><li><b>ext2:</b> Stable filesystem popular for databases (no journaling)</li></ul>|
}}
|-
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[[Image:partition_verification.png|thumb|right|550px|Carefully verify partition mount-names and sizes prior to proceeding with install. Check [http://matrix.senecac.on.ca/~murray.saul/ops235/installation/ installation screenshots] link for verification.]]
|}
:'''Perform the Following Steps:'''
# From the installation summary screen, click '''Installation Destination'''.
# In the installation destination screen, select the destination option: '''I will configure partitioning''' and then click '''Done'''.
# The manual partitioning screen should appear.
# If you have used your hard disk for previous Linux (Centos) distributions, you should remove them. Click on the distribution, and for each partition, select the partition and click the remove button (minus sign) and confirm deletion.
::Remember that the sizes are recorded in MB (eg. 30 GB = 30000 MB) and you should multiply GB by a factor of 1024 to get the correct size. (eg. '''30 GB x 1024 = 30720 MB''')<br><br>
<ol><li value="5">We will now create some mount points under the root (/) partition. '''Click on the add button (plus) sign'''.<br></li>
<li>In the '''Add a New Mount Point''', click the drop-down button and select '''/boot/efi''' (or '''/boot''' if ''/boot/efi'' is not present) for the mount point and type '''2954''' as the desired capacity, and then click '''Add mount point'''.</li>
<li>When you return to the main screen, make certain that this mount point is a '''Standard Partition''' and <u>not</u> ''LVM''.</li>
<li>Add another mount point, but in the '''Add a New Mount Point''' screen, 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.</li>
<li> 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 LVM</span>.</li>
<li>Repeat the same steps above for the '''/home''' partition (calculate the equivalent size for '''40GB''' ('''ext4''' file-system type and LVM as device type).</li>
<li>Add a mount point '''/var/lib/libvirt/images''' (type yourself, check spelling!) for size '''100GB''' (file-system type ext 4 and device type '''LVM''').</li><li>Recheck each of the created partitions, and make certain that the file-system type is set to '''ext4''' and the Device Type should be '''LVM'''.</li>
<li>Finally, add a swap partition (Mount Point: swap) for '''16 GB'''.</li>
<li>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></li>
<li>A Summary of Changes screen will appear to show the partitioning operations that will be created. Click the '''Accept Changes''' and click '''Begin Installation''' in the Installation Summary screen to proceed with the installation.</li>
</ol>
=== Part 3: Completing the Installation ===
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|[[Image:completed.png|thumb|right|500px|This screen indicates that installation is complete. You should remove the install DVD and confirm Centos7 boots from your removable hard drive. ]]
|}
:'''Perform the Following Steps:'''
#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 strong password).
#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 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).
<br><br>
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|{{Admon/important|Keep the root password the same for Host and VMs|In order to simplify running the lab checking scripts in future labs, using the same root password for ALL machines (c7host and virtual machines). Also use the same username and passwords for all of your machines (c7host and virtual machines). <b>Do not do this in a production environment!</b>}}<br><br>
|}
<ol><li value="4">When installation is complete, you will notice a message at the bottom of the screen stating: '''CentOS is now successfully installed and ready for you to use!'''</li>
<li>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.</li>
<li>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, Click on '''License Not Accepted''' and graphically accept the license and then click '''FINISH CONFIGURATION''' to finish the installation process.<br><br>'''NOTE:''' If you have an older version of Centos7, you must perform the alternative steps:<br>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></li>
<li>The system should then graphically prompt the user to login with their regular user account. Click on your '''regular user account name''' and '''enter your regular user password'''.<br><br></li>
<li>The last phase of the installation process should now run:<ul><li>Confirm English as the default input source and click '''Next'''.</li><li>Skip the creation of online accounts by clicking '''Next'''.<li>Start using your installed Linux system by clicking '''Start Using CentOS Linux'''.</li></ul><br></li>
<li>Open a web-browser and check to see if you can connect to the Internet. '''It is essential that your Host machine can connect to the Internet in order to download checking scripts, installing software and performing software updates'''.</li>
</ol>
{{Admon/important|Can't connect to Internet on your Host Machine with Removable Hard Drive|Sometimes, you may not be able to connect to the Internet when booting your Host machine from your removable hard disk drive. If that is the case, you should notice on the top right hand side of your desktop two square brackets containing dots. To fix that problem, you need to perform the following steps to temporarily place your NIC card into hibernation:<br><br><ol><li>'''Press the power button for two - three seconds'''. This should put it in suspend mode. You can confirm it is in suspend mode if the blue power light is flashing.</li><li>'''Wait a few seconds, then press the power button again'''. This will go out of suspend mode. You can confirm is is not in suspend mode if blue power light is solid (not flashing).</li><li>'''Within 30 seconds, the symbol on the top right-hand side should appear like a solid box''' (it means that you can now connect to the Internet).</li></ol>}}
'''Answer Investigation 1 observations (all parts and questions) in your lab log book.'''
=INVESTIGATION 2: COMMON POST-INSTALL TASKS=
===Part 1: Turning Off Locked Screen-saver===
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. Turning-off the locked screen-saver for this (and other) virtual machine can be useful when waiting for your instructor to come over to "sign-off" your computer lab without having to re-issue user passwords.
'''To Disable the Locked Screen-saver, Perform the following steps:'''
#Click on the '''power button at the top right-hand corner of the window'''.
#Click the '''Settings''' icon (bottom left-hand side of menu - looks like a screw-driver and wrench icon.
#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.
===Part 2: Accessing Administrative Privileges===
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{{Admon/note|Accessing the Administration Account (root)| Many administrative tasks require the root administrative account. There are many ways to access this administration account:<ul><li>Login: '''root''' (enter root password)</li><li>Switch User to root (without login):<ul><li>'''su''': Remains in regular user's directory, does not run root's startup script(s).</li><li>'''su -''' : Changes to root's home directory (/root) and runs root's start script(s).</li></ul></li></ul>}}
|}
:'''Perform the following steps:'''
#Refer to the Information box regarding how to access the admin account from the command line.
#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. When finished logout of this account.
#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. What do you notice are the 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/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.
# You can make use of this file to determine how many packages have been installed: complete the following command to count the number of packages that are labelled "Installing" in the installation log file:
:: <b><code><span style="color:#3366CC;font-size:1.2em;">grep -i packaging /var/log/anaconda/packaging.log | wc -l'''</span></code></b>
===Part 3: Disable SELinux and Perform Software Updates===
{{Admon/important|Never disable SELinux in the real world| It is highly discouraged and unsafe to disable SELinux on a public-facing server. Some applications may require tedious steps to setup SELinux rules. Disabling SELinux is never the correct way to solve an issue.}}
SELinux stands for '''Security-Enhanced Linux'''. It is a component that helps to better secure the system to protect against intrusion (hackers). SELinux is enabled upon the default install of CentOS. SELinux can be a good thing, if you take care of it and know how it works. For this course it is strongly recommended that you '''disable SELinux by default''' because we won't have the time to reconfigure it every time the labs make it necessary.
:'''Perform the following Steps:'''
# Disabling SELinux is quite simple.
# Edit the file '''/etc/selinux/config'''
# In the editing session, set SELINUX to '''disable<u>d</u>''' (from ''enforcing'') and save your editing session.
'''Answer Investigation 2 observations (all parts and questions) in your lab log book.'''
=== Part 4: Using Shell Scripting to Generate System Information Reports ===
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{{Admon/note|Bash Shell Scripting Reference Guide:|<br>'''<u>She-bang Line</u>'''<ul><li>Forces shell script to run in a specific Shell</li><li>Must be at beginning of first line (eg. '''#!/bin/bash''')<br><br></li></ul>'''<u>Variables</u>'''<blockquote>'''Environment'''<ul><li>System-wide or "global" variable</li><li>Usually appear in UPPERCASE letters</li><li>Can view with command: '''set | more'''</li><li>'''$''' in front to expand variable to value<li>Examples: '''USER''', '''PATH''', '''HOME''', '''SHELL'''</li></ul></blockquote><blockquote>'''User-defined''' <ul><li>Variable created by user (command line, scripting)</li><li>Examples:<br>''myVar="my value"; readonly myVar; export myVar''<br>''read -p "enter value: " myVar''</li></ul></blockquote><blockquote>'''Positional parameters'''<ul><li>Assign values with set command or shell script arguments</li><li>These variables are numbered (eg. $1, $2 ... $10}</li><li>Special parameters: $*, $@, $#, $$, $?<br></li></ul></blockquote>'''<u>Command Substitution</u>'''<ul><li>Useful method to expand output from a command to be used as an argument for another command.</li><li>Examples:<br>''file $(ls)''<br>''set $(ls);echo $#;echo $*''<br>''echo "hostname: $(hostname)"''<br><br></li></ul>'''<u>if / elif / else statements</u>'''<ul><li>If a command runs (even pipeline command like to grep to match) will be true (0); otherwise, false (non-zero), thus can use with logic statements.</li>Example:<br>''if echo $myVar | grep "match"''<br>''then''<br>''echo "Match"''<br>''fi''<br></li><li>The '''test''' command is used to test conditions. Square brackets '''[ ]''' is short-cut for test command (args contained inside with spaces). The '''exit''' command can be used to terminate the shell script with a false value.<br>Example:<br>''if [ $USER = "root" ]''<br>''then''<br> ''echo "You must be root" ''<br> ''exit1''<br>''fi''<br></li><li>For numberic comparison, use the '''test options''': '''-gt''','''-ge''', '''-lt''', '''-le''', '''-eq''', '''-ne'''<br>Example:<br>''if [ $grade -gt 79 ]''<br>''then''<br> ''echo "You get Good Mark"''<br>''elif [ $grade -gt 49 ]''<br>''then''<br> ''echo "You pass"''<br>''else''<br> ''echo "You fail"''<br>''fi''<br></li><li>For testing for file information, you can use '''-d''' to test if directory pathname exists, and '''-f''' if the file pathname exists. You can use '''!''' for negation.<br>Examples:<br>''if [ -d directory-pathname ]''<br>''then''<br> ''echo "directory exists"''<br>''fi''<br><br>''if [ ! - f file-pathname ]''<br>''then''<br> ''echo "File does not exist"''<br>''fi''</li></ul>}}
|}
It is very common for System Administrators to keep records regarding their installed computer systems. For example, it is necessary to have a record of all the hardware information for each machine in order to help fix computer hardware problems, and to assist when purchasing additional consistent computer hardware.
Therefore, it makes sense to also have a record of the installed computer software as well. This can contain information regarding the Linux operating system, installed software, and network connectivity information.
:'''Perform the Following Steps:'''
# Study the Linux commands and their purpose to note computer software information for your installed c7hostVM. You should take time to issue each of these commands to view the output, and record this chart in your lab1 logbook.<br><br>
# Login to your c7hostVM, open a Bash Shell terminal, and login as root by issuing the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">su -</span></code></b><br><br>
# Make certain to '''<u>record output</u>''' from these commands (except for the '''ps -ef''' output) in your lab1 logbook.
<table cellspacing="0" cellpadding="5" width="50%" style="border-top: thin solid black;margin-left:60px;">
<caption>'''Linux/Unix System Information Utilities'''</caption>
<tr valign="top>
<td style="border-bottom: thin solid black;font-weight:bold;background-color:#ffffff;">Command(s)</td>
<td style="border-bottom: thin solid black;font-weight:bold;background-color:#ffffff;">Purpose</td>
</tr>
<tr valign="top">
<td width="20%" style="border-bottom: thin solid black;"><b><code><span style="color:#3366CC;font-size:1.2em;">uname -rv</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">hostname</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">ps -ef</span></code></b></td>
<td width="20%" style="border-bottom: thin solid black;">Basic Linux OS information such as '''kernel''' version, '''host-name''' of Linux server, and all '''processes''' that are running on the system after installation.</td>
</tr>
<tr valign="top">
<td width="20%" style="border-bottom: thin solid black;"><b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a | wc -l'''</span></code></b><br><b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a -l | wc -l'''</span></code></b><br><b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">rpm -q -l gedit | wc -l</span></code></b></td>
<td width="20%" style="border-bottom: thin solid black;">Obtain number of installed packages in the rpm database. Option '''-q''' is to "query" informationo, option '''-a''' means for all installed packages, option '''-l''' means all files installed as opposed to just the application.</td>
</tr>
<tr valign="top">
<td width="20%" style="border-bottom: thin solid black;"><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">ifconfig</span></code></b><br><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">route -n</span></code></b><br><b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">nslookup</span> (at prompt, enter command: server) </code></b></td>
<td width="20%" style="border-bottom: thin solid black;">Obtain network connectivity confirmation including: '''IP ADDRESS''', '''Netmask''', '''routing''' (default gateway), and the default '''Domain Name Server'''.</td>
</tr>
</table>
:You may have learned about creating and running Bash Shell Scripts in your ULI101 course. Shell scripts help Linux users and system administrators to 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.
<ol><li value="4">Refer to the Bash Shell Scripting Reference Guide on the right-hand side prior to proceeding with this section. As you continue, you are required to make Bash Shell scripting notes in your lab1 logbook.</li>
<li>Create a directory called bin in your root home directory to store your shell scripts by issuing the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">mkdir /root/bin</span></code></b></li>
<li>Change to that newly-created '''bin''' directory</li>
</ol>
:'''NOTE:''' Although it is possible to copy and paste, is it highly recommended to manually enter the following Bash Shell scripting content to become familiar with writing Bash Shell scripting code. Remember: you will be required to create a Bash Shell script on your final exam, so you need the practice!
<ol>
<li value="7">Launch a text editor (such as <b><code><span style="color:#3366CC;font-size:1.2em;">vi</span></code></b> or <b><code><span style="color:#3366CC;font-size:1.2em;">nano</span></code></b>) to create a Bash Shell script called: <b><code><span style="color:#3366CC;font-size:1.2em;">myreport.bash</span></code></b> in your current directory.</li>
<li>Copy and paste the text below into your vi editing session for your file report.bash<br> (how do you copy and paste efficiently in Linux?)<br></li></ol>
<code style="color:#3366CC;font-family:courier;font-size:.9em;margin-left:20px;font-weight:bold;">
<br>
#!/bin/bash<br>
<br>
# Author: *** INSERT YOUR NAME ***<br>
# Date: *** CURRENT DATE ***<br>
#<br>
# Purpose: Creates system info report<br>
#<br># USAGE: ./myreport.bash<br>
<br>
if [ $USER != "root" ] # only runs if logged in as root<br>
then<br> echo "You must be logged in as root." >&2<br>
exit 1<br>
fi<br>
</code>
<br>
<ol><li value="9">Save your editing session, assign the '''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 work?</li><li>Reopen your text-editing session for '''/root/bin/myreport.bash''' and add the following lines of code to the bottom of the shell script file:</ol>
<br>
<code style="color:#3366CC;font-family:courier;font-size:.9em;font-weight:bold;">
# Create report title<br>
<br>
echo "SYSTEM REPORT" > /root/report.txt<br>
echo "Date: $(date +'%A %B %d, %Y (%H:%M:%p)')" >> /root/report.txt<br>
echo >> /root/report.txt<br>
</code>
<br>
<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 > is used at the beginning of the report, and then the other redirection symbol >> 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>
<br>
<code style="color:#3366CC;font-family:courier;font-size:.9em;font-weight:bold;">
echo >> /root/report.txt<br>
echo "Hostname: $(hostname)" >> /root/report.txt<br>
echo >> /root/report.txt<br>
echo "Kernel Version: $(uname -rv)" >> /root/report.txt<br>
echo >> /root/report.txt<br>
</code>
<br>
<ol><li value="10">Save, run the script, and view the ''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><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:<br><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><br><br></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>
'''Answer Investigation 2 observations (all parts and questions) in your lab log book.'''
= LAB 1 SIGN-OFF (SHOW INSTRUCTOR) =
[[Image:lab1_signoff.png|thumb|right|450px|Students should be prepared with '''all required commands (system information) displayed in a terminal (or multiple terminals) prior to calling the instructor for signoff'''.]]
Shell scripting is <u>so essential</u> for Linux administration that this course has created a shell script for every lab for this course that a student must download and run in order to check their work.
If you have performed the lab correctly, then you will get a series of <b><span style="color:#66cc00;border:thin solid black;font-size:1.2em;"> OK </span></b> messages and you can proceed with the SIGN-OFF for lab1. On the other hand, if there were errors, then a <b><span style="color:#ff0000;border:thin solid black;font-size:1.2em;"> WARNING </span></b> message will appear with general suggestions that you will need to fix on your c7hostVM in order to have your OPS235 sign-off in this lab in order to proceed to the next lab.
:'''Perform the Following Steps:'''
# Make certain that your '''c7host''' VM is running, open the Bash Shell terminal and issue the command: <b><code><span style="color:#3366CC;font-size:1.2em;">su -</span></code></b> and enter root's password.<br><br>
# Change to the '''/root/bin''' directory.<br><br>
#Download the checking script by issuing the following Linux command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">wget http://matrix.senecac.on.ca/~murray.saul/ops235/lab1-check.bash</span></code></b><br><br>
# Give that downloaded shell script file execute permissions (for the file owner).<br><br>'''FYI:''' Your this checking script will not work unless you issued "'''su -'''" instead of just "'''su'''".<br><br>
# Run the shell script and if any warnings, make fixes and re-run shell script until you receive "congratulations" message.<br><br>
#Arrange evidence (command output) for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:
::<span style="color:green;font-size:1.5em;">✓</span> Output of '''lsblk''' command showing correct partition names and sizes
::<span style="color:green;font-size:1.5em;">✓</span> Run the '''lab1-check.bash''' script in front of your instructor (must have all <span style="color:#66cc00;border:thin solid black;font-size:1.2em;"> OK </span> messages)
::<span style="color:green;font-size:1.5em;">✓</span> '''Lab1 logbook''' containing the values for:
:::* '''IP address''', '''MAC address''', '''Default route (gateway)''' and<br>'''DNS name server IP Address'''
= Practice For Quizzes, Tests, Midterm & Final Exam =
# Why do you need to create a host machine before using a virtual machine?
# List the major screens (steps) in the installation of Centos7 full install DVD.
# List the steps for disabling SELinux.
# List 2 ways that you can access your root account
# What is the difference between the commands '''su''' and '''su -''' ?
# What is the home directory for the user "root"?
# How do you determine the host name of your GNU/Linux workstation?
# What command can display the NIC's MAC address?
# What command is used to get a list of running processes on your newly-installed system?
# Write the Linux command to download the on-line file: http://linux.server.org/package.tar.gz
# Write a Bash Shell Script to prompt the user for a directory, and then display the file types for all files in that specified directory (hint: use the '''read''' command and then use the '''file''' command and '''command substitution''' with the '''ls''' command). Test the Bash Shell script by adding execute permissions and run the Bash Shell Script.
# Modify the previously created shell script to perform error checking after prompting for a directory to test if the specified directory does not exist. If it does NOT exist (i.e. true), display an error message indicating that the directory does NOT exist, and issue the command exit 1 to terminate the Bash Shell Script. Test the Bash Shell script by adding execute permissions and run the Bash Shell Script.
[[Category:OPS435]]
[[Category:OPS435 Labs]]
