Changes

The There are many other tasks that a Linux OS you will be system administrator must perform other than installing in this lab will be a Host Machine (''hostname'': '''c7host''') that will allow you to run '''Virtualization Software''' to create 3 separate virtual machines (to be performed in lab2)Linux and installing software. It is important to install this host machine correctly since other labs will depend on the stability of this host machine A few additional tasks are user management and managing services.

:* Administer '''Correctly install (add, remove, modify) users''' on a Linux system.:* Save time while adding new users using a template of '''start-up files'''.:* Create and manage '''groups''' on a Linux system.:* '''Start and Stop services''' on a Linux system.:* Display the CentOS 7 FULL INSTALL DVD''' (not LIVE DVD) status of running services''' on your removable hard diska Linux system.

{|cellpadding="15" width=Minimum Required Materials=={|"40%"

| [[Image:blank-cd.png|thumb|left|75px|<b>CentOS 7</b>FULL INSTALL DVD]] width="10%" | [[Image:harddrive.png|thumb|left|75px85px|<b>Removable Hard Disk Pack</b> (SATA)]]

|width="10%" | [[Image:ubs-key.png|thumb|left|75px85px|<b>USB key</b><br>(for backups)]]

|width="10%" | [[Image:log-book.png|thumb|left|60px70px|<b>Lab Lab4 Log Book</b><br>(labs 1 & 2)]]

{| width="10050%" cellpadding="15"

|width="10%" |<u>Package User Management:</u>[http://unixhelp.ed.ac.uk/CGI/man-cgi?useradd+8 useradd]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?userdel+8 userdel]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?usermod+8 usermod]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?groupadd+8 groupadd]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?groupdel+8 groupdel]|width="10%" |<u>Managing Services</u>[http://unixhelp.ed.ac.uk/CGI/man-cgi?chkconfig+8 chkconfig]<br>[http://unixhelp.ed.ac.uk/CGI/man-cgi?service+8 service]<br>[http://www.rpmdsm.fordham.edu/cgi-bin/man-cgi.pl?topic=systemctl systemctl]<br>|width="10%" |<u>Miscellaneous</u>[http://man7.org/maxlinux/man-rpmpages/man5/rpmpasswd.85.html rpm/etc/passwd]<br>[http://man7.org/linux/man-pages/man8man5/yumgroup.85.html yum/etc/group]<br>|[http://man7.org/linux/man-pages/man5/shadow.5.html /etc/shadow]<ubr>System Information[http://archive.linuxfromscratch.org/blfs-museum/1.0/BLFS-1.0/postlfs/skel.html /etc/skel]<br>[http://u>zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd init vs systemd]|}  = INVESTIGATION 1: User/Group Management =

[http://man7.org/linux/man-pages/man1/hostname.1.html hostname]<br>[http://man7.org/linux/man-pages/man1/unameUser account management is a very important operation that a Linux sysadmin does on a consistent basis.1The sysadmin not only needs to add or remove user accounts by issuing commands, but may need to automate user account creations a large number (batch) of potential employees.html uname]<br>[httpThere are many features with the Linux command to create new users including://man7.org/linux/manspecification of a home directory, type of shell used, name, password and time-pages/man1/ps.1limit (referred to as "aging") for a new user account.html ps]<br>[http://man7.org/linux/manRemove user accounts also have options such as removing the user account but keeping the home directory for reference or evidence of "wrong-pages/man8/lsblk.8.html lsblk]<br>|<u>Networking</u>doing"

[http://man7In your ULI101 course, you learned to change permissions for directories and files relating to user, same group members and other group members.org/linux/man-pages/man8/ifconfigIn this course, since you are the sysadmin with root privileges, you can create or remove groups as well as change the ownership of directories and files! We will now learn to perform key user account management operations in this section.8.html ifconfig]<br>[http://man7.org/linux/man-pages/man8/netstat.8.html netstat]<br>[http://man7.org/linux/man-pages/man8/route.8.html route]<br>[http://linux.die.net/man/1/nslookup nslookup]<br>|<u>Miscellaneous</u>

[http://unixhelp.ed.ac.uk/CGI/man-cgi?grep 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.== Part 1.html more]<br>[http:The /etc/man7.org/linux/man-pages/man1/passwd 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>[http://man7.org/linux/man-pages/man1/scp.1.html scp]<br>[http://ss64.com/vi.html vi]==

|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 ULI101 as well as essential shell scripting skills. Login to your '''Matrix''' account, and issue # Look at the pathnames to run the online tutorial in Matrix:<brb><ulcode><li>Using the vi Text Editorspan style="color:#3366CC;font-size:<br1.2em;">'''/homeetc/murray.saulpasswd</vi-tutorial'''span><br/code><li/b>Linux Basicsfile.# Make note of the contents of that file.# Read about the file: http:<br>'''/home/murrayman7.saulorg/linux-basics'''</li><li>Shell Scripting man- Part I (Scripting Basics):<br>'''pages/homeman5/murraypasswd.saul/scripting-1'''</li></ul>|5.html # Make sure you know what information each field contains.# Why do you think there are so many users?# Look at the names of the users. What do you think these user names represent? Are they people?}}# What is the numeric user ID (UID) of the root user?|}# The user IDs of real users (people) are different from the user IDs of system accounts. What is the pattern?

=INVESTIGATION '''Answer the Part 1: CREATE HOST MACHINE (c7host)=observations / questions in your lab log book.'''

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== Part 2:<ul><li>'''/''' (The "root" partition)</li><li>'''/home''' (Store regular user accounts)</li><li>'''/var/lib/libvirt/images''' (store virtual machine images to be created in lab2)</li><li>'''swap''' partition (Virtual Memory)</li></ul>Adding users ==

#Perform this part in your '''centos1''' VM.# Read the man page for the <b><code><span style="color:#3366CC;font-size:1.2em;">useradd</span></code></b> command.# Create three fictitious users (make-up their userids and full names. Give each of these newly-created users a password.# Grep the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/passwd</span></code></b> file for each of the new users.#* What is the '''home''' directory of each user?#* What '''group''' is each user in?#* What other information can you provide regarding these users?#* Where are the '''passwords''' stored?# Look at the man page for '''/etc/shadow''' using the command: <b><code><span style="color:#3366CC;font-size:1.2em;">man 5 shadow</span></code></b>#* Grep the <b><code><span style="color:#3366CC;font-size:1.2em;">/etc/shadow</span></code></b> file for each of the new users.#* Make note of this information. # Create two new dummy users, <b><code><span style="color:#3366CC;font-size:1.2em;">ops235_1</span></code></b> and <b><code><span style=Part "color:#3366CC;font-size:1.2em;">ops235_2</span></code></b>.# Investigate the home directory of one of your new users.#* What files are there? Be sure to include hidden files.#* What do you think these files are used for?#* How does the operating system determine which files are created in a new home account? The answer can be found here: Start Installation <br>http://www.linuxhowtos.org/Tips%20and%20Tricks/using_skel.htm#* Look at the files (including hidden files) in the template directory referred to in the article. Compare them to what is in a home directory for a new user. What do you notice?#* Create a new file in this directory with the following command: <b><code><span style="color:#3366CC;font-size:1.2em;">touch foo</span></code></b>#* Create a new user named <b><code><span style="color:#3366CC;font-size:1.2em;">foobar</span></code></b>, with the option to automatically create a home directory.#* Look at the contents of foobar's home directory. What do you notice?# Be sure to record your observations in your lab notes.#Issue the man pages for the '''useradd''' command. Explain the purpose of using the '''-e''' option for the ''useradd'' command. Try to think what would be the purpose for a Linux sysadmin to use this option when creating new users.

#Remain in your '''centos1''' VM for this section.# Read the man page for the <b><code><span style="color:#3366CC;font-size:1.2em;">groupadd</span></code></b> and <b><code><span style="color:#3366CC;font-size:1.2em;">groupdel</span></code></b> commands.# Note which option allows you to set the Group ID number ('''GID''') when you create a new group.# Examine the file <ub>Host Machine Details<code><span style="color:#3366CC;font-size:1.2em;">/etc/group</span></ucode></b>#* Which values of GID are reserved for system accounts?#* Which values of GID are reserved for non-system user accounts?#* What is the lowest available GID number for non-system users?#* What is the default group name of a new user?#* Add a new group named <b><code><span style="color:#3366CC;font-size:1.2em;">ops235</span></code></b> with a GID of <b><code><span style="color:#3366CC;font-size:1.2em;">600</span></code></b>.#* The management at your organization have concerns regarding some irresponsible users on your system.#** Add a new group named '''investigation'''.#** Look at '''/etc/group''' and note the GID of group called '''investigation'''.#** What GID is given to a new group if you do not specify it?#** In the file, add those users to the end of the concerned group (separate each user-name with a comma).#** Those individuals have explained their actions to management and the crisis has been resolved. Delete the '''investigation''' group.#** Look at '''/etc/group'''again and note the change.

::*'''Name:''' c7host::*'''Boot media Answer the Part 3 observations / Installation:''' CentOS7 Full Install DVD::*'''Memory:''' 8GB::*'''Disk space:''' 250GB (or higher)::*'''CPUs:questions in your lab log book.''' 1

{| width="40%" align="right" cellpadding="10"|- valignPart 4: Deleting / Modifying Users ="top"|colspan="2"|{{Admon/important |You're supposed to use this hard drive only for this course| But if you really need to use it for two courses, and the professor for the other (probably windows) course will allow it - ask your professor for help with partitioning.}}|- valign="top"|[[Image:lab2-logbook.png|thumb|right|100px|'''comparison chart''' in lab2 logbook.]]|[[Image:installation_summary.png|thumb|right|400px|The '''Installation Summary''' screen provides flexibly when configuring to install on your computer. ]]|}

# Refer to this listing of installation screenshots if you need a reference:<br>[ [http://matrix.senecac.on.ca/~murray.saul/ops235/installation/ installation screenshots] ]<br># Insert Remain in your '''removable SATA hard diskcentos1''' into the drive trayVM for this section.# Set your computer's drive selector switch to Read the man page for the '''externaluserdel''' (acommand.k.a ''position #4'')Note which option automatically removes the users home directory when that user is deleted.# Power up the computer and insert Delete the user '''CentOS 7 Installation DVDops235_1''' into the DVD drive, then power-off computer.# Determine if your computer is using the command <ub>newer</ucode> or <uspan style="color:#3366CC;font-size:1.2em;">olderuserdel ops235_1</uspan> model. '''Newer computer models''' are labelled '''HP Z230'''.<br/code><br/b># Delete the user '''NOTE:ops235''' If _2 using the same command with the option which removes the home directory of the user.# Check the contents of the /home directory. What do you are using notice?# Check the contents of the '''<ub>newer</ucode>''' model, allow the computer to boot up (<uspan style="color:#3366CC;font-size:1.2em;">without/etc/group</uspan> pressing F10 key) to boot from DVD. For <u/code>'''older'''</ub> models, press F10, press ENTER file. What do you notice?# Read the man page for password, and select the DVD driveusermod command. Refer to Note which options change the comparison chart in lab2 lab logbook, and fill in various installation information for user'''c7host''' while you perform the installation (such as time it took to perform a s full installname, installation optionsprimary group, supplementary groups, etc)and shell.<br><br># Create a new user account called '''WARNING:noobie''' Only use for the same type of computer (only the <u>employee: '''newer"Really Green"'''</u> computer or only . Assign a password for that newly created user.# Management has indicated that this employee be on on probation for 3 months. Use the <u>'''olderusermod'''</u> computer) when working in command to set the Seneca labs account for noobie to expire in 3 months from this day as part of the duration security policy of this course!<br>organization.# Add each of your new users to the group ops235 (in other words, add ops235 to each user as a supplementary group).# Examine <brb><olcode> <li valuespan style="6color:#3366CC;font-size:1.2em;">Select /etc/group</span></code></b>. What has changed?# Use the option '''Test this Media & Install Centos7usermod'''. Your DVD will be checked for defects.</li> <li>If command to change the check is successful, you will be prompted for a language. In full name of the first screen, select language user account '''Englishnoobie''' with subselection from '''English-Canada"Really Green"''' and then click the to '''Continue"Outstanding Employee"''' button on . Examine the result of running that command in the bottom right<b><code><span style="color:#3366CC;font-hand screensize:1.2em;">/etc/passwd</span></licode></b> file. What has changed?# Use the '''usermod''' command to extend the use of their account for 5 years as of today.# Be sure to record your observations in your lab notes.

<li>The '''Install Summary''' should now appear. This screen allows Answer 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<Part 4 observations /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 questions in your settings, then click the <b>DONE</b> button at the top-left corner to finish and return to the Installation Summary screenlab log book.</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>

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/tip|Mount Points and Linux File System Types|Similar The process may not be hard, but knowing how to other Operating Systems like windows '''fat''' / '''vfat''' / '''ntfs''' file system typesstop, start, it restart and check the status of services is good absolutely critical to know a few common file system types in Linux for comparison:<br><ul><li><b>xfs:</b> &nbsp; Newer filesystem (fast transfer rates for large files, Journaling)</li><li><b>ext4:</b> &nbsp; Newer filesystem supporting large files and Journaling (used in for this lab)</li><li><b>ext2:</b> &nbsp; Stable filesystem popular for databases (no journaling)</li></ul>|}}|-|[[Image:partition_verification.png|thumb|right|550px|Carefully verify partition mount-names and sizes prior to proceeding with install. Check [http://matrix.senecacserver.on.ca/~murray.saul/ops235/installation/ installation screenshots] link for verification.]]|}#From the installation summary screen, click '''Installation DestinationAside from learning to trouble-shoot problems'''.#In by checking the installation destination screenstatus of running services, 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 understanding how to manage services is critical to help protect a 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.#Change the option '''New mount points will use the following partition scheme''' server from penetration'''LVM''' (this term is referred to as "'''<u>Standard Partition</u>Hardening a system''' (you will not be using LVM for your c7host machine").#Before you proceed with creating partitions, let's see the partitions that Sometimes it is "what we need to create for our host computer:<ul><li>Primary Partitions (ext4):<ul><li>don'''30GB''' for '''/''' (i.e. "roott know")</li><li>'''40GB''' for /home</li><li>'''100GB''' for '''/var/lib/libvirt/images''' </li></ul> </li><li>Swap Partition:<ul><li>'''16GB''' (Note: "swap" must be selected from the drop down menu)</li></ul></li></ul><br>'''NOTE:''' Remember that the sizes are recorded can harm us. One key element in MB (eg. 30 GB = 30000 MB) and you should multiply GB by hardening a factor of 1024 computer system is to disable non essential networkng services to get the correct size.<br> allow IDSs (eg. '''30 GB x 1024 = 30720 MBIntrusion Detection Systems''')<br><br>#We will now create the root (/) partitionto focus on a narrower range of policy violations. '''Click on the add button A Debian-based penetration testing distribution called Kali (plus) sign'''.<br>#In the '''Add a New Mount Point''' screen, select formerly referred to as '''/BackTrax''' as the mount-point (either by typing or selecting from drop-down menu), allows sysadmins and enter '''30720''' security professionals to identify vulnerabilities in for partition size their computer systems, and click '''Add Mount Point''' button.#Repeat the same steps above for the '''/home''' partition and '''/var/lib/libvirt/images''' partitionthus improve (harden) their systems against penetration. You need Learning to type monitor the ''/var/lib/libvirt/images'' partition since it does not appear in the drop-down menu.#Select each of the created partitionsstatus, enable and make certain that disable networking services underlies the file-system type is changed from '''xfs''' to Backtrax'''ext4'''.#Finally, add a swap partition (Mount Pointmotto: swap) for <br><br>'''16 GB'''.#Check that your partition settings "The quieter you are correct (you can ask your instructor or lab monitor to confirm), and then click '''Done''' to proceedmore you will hear..#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.#Start timing your host machine installation.<br><br>

== Part 3: Completing We have seen that maintaining unneeded '''packages can be a security risk''' due to the Installation ==unnecessary increase in the complexity of your system. Similarly, it is also unnecessarily hazardous, and even more so, to leave unneeded services running. In this investigation, we will learn how to '''control services, and turn off those services that we think are not necessary to help reduce security risks'''.}}

{|width="40%" align="right" cellpadding="10"|- valign="top"|[[Image:completed.png|thumb|right|500px|This screen indicates that installation is complete. You should remove the install DVD and confirm Centos7 boots from #Use your removable hard drive. ]]|}#During the installation process, you will required to create a '''root passwordcentos2''' (VM for administration access) and create a '''regular user account'''this part. Click on <ol> <li value="2">Use the '''Root Passwordman''' and enter your root password. Think of an appropriate password and record that password somewhere in case you forget! An indicator will appear pages to show you how secure your password is. Retype your root password and click learn about the '''Doneservice''' (you may have to click Done command.<u/li>twice</uli> 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 Issue the following 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). <ul> <li><b><code><span style="color:#Remember to record this host installation information in the '''installation comparison chart''' in the lab2 logbook.#When installation is complete, you will notice a message at the bottom of the screen stating3366CC;font-size: '''CentOS is now successfully installed and ready for you to use!'''#Click the Reboot button1. Your DVD will 2em;">service --status-all</span></code><u/b>briefly</uli> 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 (what is the purpose of accepting the license?). </ul>#Click on '''License Information''' and '''click that you agree to the license agreement''', click '''Done''' and then click '''Finish Configuration'''. </li>#Click Forward to enable Kdump (what is <li>Note the purpose of this application?)services that are currently running.</li>#The system should then graphically prompt <li>Use the user to login with their regular user account. Click on your '''regular user account name''' and '''enter your regular user password'''.command <brb><brcode><span style="color:#The last phase of the installation process should now run3366CC;font-size:1.2em;">service iptables stop</span><ul/code><li/b>Confirm English as to stop the default input source and click service named '''Nextiptables'''.</li> <li>Skip Run a command to verify that the creation of online accounts by clicking '''Nextiptables'''service has stopped.</li>Start <li>A newer method of managing services is by using your installed Linux system by clicking '''Start Using CentOS Linuxsystemd'''.</li></ul><br>#Stop timing your installation and note It has the amount of time that your installation took ability to perform. Also take the time manage dependent service in parallel and allow one service to fill in the c7host section of be stopped without disrupting the installation comparison chart in your lab2 logbookother services.#Open Here is a web-browser and check link that briefly explains how to see if you can connect use '''systemd''' (as opposed to tradition method: ''init'') and the Internet.<br><br>#Your system automatically enables a '''screen-saversystemctl''' application which is a useful security tool to prevent unauthorized viewing of information command: [http://zenit.senecac.on a terminal after a certain amount of inactivity. ca/wiki/index.php/Init_vs_systemd init vs systemd]</li> <li>If you find this feature annoying and reboot now - the iptables service will be turned back on. We don't want to it on though, it causes students headaches. To turn it off or adjust permanently we need to use the idle time perform the following steps'''chkconfig''' command:<ol typebr><b><code><span style="acolor:#3366CC;font-size:1.2em;">chkconfig iptables off<li/span>Click on your '''username at the top right-hand screen'''</licode><li/b>Select '''Settings''' from the drop-down menu</li> <li>Click Use the '''Powersystemctl''' icon located in command (from the ''Settings'' Dialog Box</li><li>Change the amount of time in link above - showing examples) to verify that the '''Power Savingiptables''' section to service is off ('''Neverhint:''' or a issue command, and pipe to grep "'''longer period of timeiptables'''"). </li><li>Close the Reboot and confirm that it''Settings'' Dialog boxs no longer running.<br><br></li></ol>#Proceed to Investigation 2 to obtain basic information from your newly installed Centos Host machine.

'''Answer Investigation Part 1 observations (all parts and / questions) in your lab log book.'''

=INVESTIGATION ==Part 2: OBTAINING HOST MACHINE SYSTEM INFORMATIONHow do we Manage Runlevels?===

==Part 1: Obtaining Package Management The Linux sysadmin can also change the run-level (or state) of a graphical Linux server to run in text-based mode and run the graphical mode by issuing a command when graphic mode is required. The run-level term is now deprecated in Fedora, and will likely be deprecated in RHEL/ Package Information==CentOS at some point as well, but for now this is what the industry is using.

<ol><li value="12">Issue the following command to obtain the total number of files installed for gedit:<br><br></li></ol>::<b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1Perform this part in both your '''centos2''' and '''centos3''' VMs.2em;">rpm -ql gedit | wc -l</span></code></b>

<li value="132">Using what you learned Issue the following Linux command: <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">runlevel</span></code></b></li> </ul> </li> <li>Note the difference in steps 3, 4, output between '''centos2''' and 7, get '''centos3'''.</li> <li>You can use the '''init''' command to change the current run-level. See a count list of runlevels [https://www.centos.org/docs/5/html/5.2/Installation_Guide/s2-init-boot-shutdown-rl.html here].</li><li> Use the '''man''' command to learn how to use the '''init''' command. Use this command to change the total number of files installed by all of current run-level in '''centos2''' to '''3'''. What happened?</li> <li>Issue the software packages on following Linux command: <ul> <li><b><code><span style="color:#3366CC;font-size:1.2em;">startx</span></code></b></li> </ul> </li> <li>What happens?</li> <li>Log-off your graphical system. You should return to your shell prompt.</li> <li>Using systemd requires a different method of setting text mode and graphical mode. You can refer to this link for future reference: [http://fedoraproject.org/wiki/Systemd#How_do_I_change_the_runlevel.3F How can to Change Run-Levels with Systemd]</li><li>Restart your centos2 machine, and make certain that it runs in '''graphical''' mode</li> </li>Why would you explain why this number is want to make a lot larger than the total number of packages installedgraphical Linux system run in text-based mode? Record your answer in your lab logbook.</li>

==Part2: Obtaining System Information== {|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/important|Pathname for USB Stick|The default mount location has been changed in linux distributions newer than CentOS. So while we will get '''/media/usb-device-name''', in newer distributions you'll see '''/run/media/userloginid/usb-device-name'''}}|}#To find out the name that you have assigned to your Linux system, enter the command: <b><code><span style="color:#3366CC;font-size:1.2em;">hostname</span></code></b>#To find out the kernel version of your GNU/Linux workstation and the date it was created, enter the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">uname -rv</span></code></b>#To find out all the system processes running on your GNU/Linux workstation, enter the command: <b><code><span style="color:#3366CC;font-size:1.2em;">ps -ef</span></code></b>#We will now collect networking information for your installed system.#To check the network configuration settings obtained from the DHCP server, run the following commands, describing the output in your log book:::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">ifconfig</span></code></b>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">route -n</span></code></b>:::<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''' and record the output. Type exit to leave nslookup).<ol><li value="8">Find the following information in the output of the above commands:</li></ol>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">MAC address</span></code></b> of the ethernet network interface:::<b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">Subnet mask</span></code></b>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">The IP address </span></code></b> (assigned to you by the DHCP server)::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">The default gateway</span></code></b>::: <b><code><span style="pointer-events: none;cursor: default;color:#3366CC;font-size:1.2em;">The DNS nameserver</span></code></b><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>  '''Answer the Investigation Part 2 observations / questions in your lab log book.'''

==Part 1: Disable SELinux and Perform Software UpdatesAutomating Routine Tasks (Shell Scripting)== 

{{Admon/importanttip|SELinuxBash Shell Scripting Tips:|SELinux stands for <br><ul><li>'''Security-Enhanced LinuxThe case statement:'''. It <br><br>The case statement is a component control-flow statement that helps to better secure works in a similar way as the system to protect against intrusion if-elif-else statement (but is more concise). This statement presents scenerios or "cases" based on values or regular expressions (hackersnot ranges of values like if-elif-else statements). SELinux After action(s) are taken for a particular scenerio (or "case"), a break statement (''';;''') is enabled upon used to "break-out" of the statement (and not perform other actions). A default install of CentOScase (*) is also used to catch exceptions. SELinux can be <br><br><u>'''Examples (try in shell script):'''</u><br><br>''read -p "pick a door (1 or 2): " pick<br>case $pick in<br>&nbsp; 1) echo "You win a car!" ;;<br>&nbsp; 2) echo "You win a good thing, if you take care bag of it dirt!" ;;<br>&nbsp; *) echo "Not a valid entry"<br>&nbsp;&nbsp;&nbsp;&nbsp; exit 1 ;;<br>esac''<br><br>''read -p "enter a single digit: " digit<br>case $digit in<br>&nbsp; [0-9]) echo "Your single digit is: $digit" ;;<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; *)&nbsp;echo "not a valid single digit"<br>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; exit 1 ;;<br>esac''<br><br></li><li>'''The getopts function:'''<br><br></li></ul>The getopts function allows the shell scripter to create scripts that accept options (like options for Linux commands). This provides the Linux administrator with scripts that provide more flexibility and know how it worksversatility. A built-in function called '''getopts''' (i.e. For this course it get command options) is strongly recommended that you used in conjunction with a '''while''' loop and a '''case'''disable SELinux by defaultstatement to carry out actions based on if certain options are present when the shell script is run. The variable '''$OPTARG'' because we won't have can be used if an option accepts text (denoted in the time to reconfigure it every time getopts function with an option letter followed by a colon. Case statement exceptions use the labs make it necessary''':)''' and '''\?)''' cases for error handling.<br><br>'''<u>Example of getopts</u>''' (try in script and run with options)<br><br>''while getopts abc: name<br>do<br>&nbsp; case $name in<br>&nbsp; &nbsp; a) echo "Action for option \"a\"" ;;<br>&nbsp; &nbsp; b) echo "Action for option \"b\"" ;;<br>&nbsp; &nbsp; c) echo "Action for option \"c\""<br>&nbsp; &nbsp; &nbsp; &nbsp; echo Value is: $OPTARG" ;;<br>&nbsp; &nbsp; :) echo "Error: You need text after -c option"<br>&nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>&nbsp; &nbsp; \?) echo "Error: Incorrect option"<br>&nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>esac''<br><br>}}

{|width="40%" align="right" cellpadding="10"|- valign="top"|{{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 shellDownload, study, it is recommended to force running and run the following 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 Issue 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><lib>'''Variables:'''<brcode><br> There are 3 types of variables that can be used in shell scripting: '''ENVIRONMENT''' (eg. $USER), '''userspan style=" pointer-defined''' ($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 Substitutionevents:'''<br><br>A very useful trick to take output from a command to be used as an argument for another command. Examples includenone;cursor:<br>'''file $(ls)'''<br>'''set $(ls)default;echo $color:#3366CC;echo $*'''<br>'''echo "hostnamefont-size: $(hostname)1.2em;"'''<br><br><li>'''Logic Control Flow Statementswget https:'''<br><br>The '''test''' command can be used to see if a condition is true or false<br>(i//scs.esenecac. test $USER &#61; "root") on. The '''$?''' 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<ca/u> the brackets (spaces separating brackets)~murray.Can use '''if''' saul/ '''if-else''' / '''if-elifuser-else''' statements with brackets. The '''exit''' command can be used to terminate the shell script with a false valuecreate.bash<br/span><br>'''<u/code>Examples</ub>'''<br><br>''if [ $USER &#61; "root" ]''<br>''Try to understand what these Bash Shell scripts do, and then''<br>&nbsp;''echo "You must be run the script as root" >&amp;2''<br>&nbsp;''exit1''<br>''fi''<br><br># For number comparison: use:<br># -gt. After running the shell script,-ge, -lt, -le, -eq, -ne<br><br>view the contents of the ''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>/home''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 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 directory to view Shell Scripting Tips which are located on the right-hand sideconfirm.

Perform Although the following steps in '''zenity''' command is a "user-friendly" way to run shell scripts, Linux administrators usually create shell scripts that resemble common Linux commands. In this lab, you will learn to create a shell script using the getopts function to make your shell script behave more like actual Linux commands (including the use of options). Refer to the notes section on the right-hand-side for reference about the '''case''' statement and the '''c7hostgetopts''' machine:function.

&#35;!/bin/bash<br>

if [ $USER PWD != "/root" ] # only runs if logged in as root's home directory<br>then<br>&nbsp;echo "You must be logged in as root's home directory." >&2<br>

<ol><li value="46">Save your editing session, assign but remain in 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;">text editor./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 code displayed below uses the Bash Shell Script?</li><li>Issue getopt function set the command <b><code><span style="color:#3366CC;font-size:1input file pathname or check for invalid options or missing option text.2em;">su -</span></code></b> and run Add the script 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></following 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>

echo outputFlag="SYSTEM REPORTn" <br>while getopts i: name<br> /root/report.txtdo<br>&nbsp;case $name in<br>&nbsp; &nbsp;i) inputFile=$OPTARG ;;<br>&nbsp; &nbsp;:) echo "DateError: $(date +'%A %B %d, %Y (%H:%M:%p)')You need text after options requiring text" <br>&nbsp; &nbsp; &nbsp; &nbsp;exit 1 ;;<br> /root/report.txt&nbsp; &nbsp;\?) echo "Error: Incorrect option"<br>echo &nbsp; &nbsp; &nbsp; &nbsp; exit 1 ;;<br>&nbsp;esac<br> /root/report.txtdone<br>

<ol><li valuecode style="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 &gtcolor:#3366CC; is used at the beginning of the report, and then the other redirection symbol &gtfont-family:courier;&gtfont-size:.9em; 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>

if [ ! -f $inputFile ]<br>then<code style=br>&nbsp; echo "The file pathname \"$inputFile\" is empty or does not exist"color:#3366CC>&2<br>&nbsp;font-family:courier;font-size:.9em;"exit 2<br>echo fi<br><br> set $(sed 's/root/report.txt+/g' $inputFile) # temporarily convert spaces to + for storing lines as positional parameters<br><br>for x<br>do<br>&nbsp; &nbsp; useradd -m -c "$(echo $x | cut -d"Hostname: " -f2 | sed 's/+/ /g')" -p $(hostnamedate | md5sum | cut -d" " -f1)$(echo $x | cut -d":" >> /root/report.txt-f1)<br>&nbsp; &nbsp; mail -s "Server Account Information" $(echo $x | cut -d":" -f3) <<+<br>&nbsp; &nbsp; Here is your server account information:<br> /root/report&nbsp; &nbsp; servername: myserver.senecac.on.txtca<br>&nbsp; &nbsp; username: $(echo $x | cut -d"Kernel Version:" -f1)<br>&nbsp; &nbsp; password: $(uname date | md5sum | cut -d" " -rvf1)" <br>&nbsp; &nbsp; Regards,<br>&nbsp; &nbsp; IT Department<br>+<br>done<br> /root/report.txt<br>echo -e "\n\nAccounts have been created\n\n"<br>> /root/report.txtexit 0<br>

'''Answer the Investigation 3 observations / questions in your lab log book.'''

= LAB 1 SIGN-OFF (SHOW INSTRUCTOR) =[[Image:lab1_signoff.png|thumb|right|500px|Students should be prepared with a'''ll required commands (system information) displayed in a terminal (or multiple terminals) prior to calling the instructor for signoff'''.]]'''Arrange evidence (command output) for each proof of these items the following on your the screen, then ask your instructor to review them and sign off on the lab's completion:'''

::<span style="color:green;font-size:1.5em;">&#x2713;</span> Output of Account created on '''lsblkcentos1''' command showing correct partition names and sizesVM.::<span style="color:green;font-size:1.5em;">&#x2713;</span> Contents List contents of '''/etc/fstabgroup''' file confirming partitions file types are (ops235 group) on '''ext4centos1'''VM.::<span style="color:green;font-size:1.5em;">&#x2713;</span> Correct List contents of '''IP address/etc/passwd''' and file (created accounts) on '''MAC addresscentos1'''VM.::<span style="color:green;font-size:1.5em;">&#x2713;</span> Display current run-level status on '''Default route (gateway)centos2'''::<span style="color:green;font-size:1VM.5em;">&#x2713;</span> '''DNS name server IP Address'''::<span style="color:green;font-size:1.5em;">&#x2713;</span> Contents Creation of your '''report.bash''' shell script::<span style="color:green;font-size:1.5em;">&#x2713;</span> proof of called '''yum update''' performed on c7host::<span style="color:green;font-size:1createUsers.5em;">&#x2713;</span> '''lab1 notes''' <u>and</u> bash'''first column of Comparison Chart in lab2'''.

= ADDITIONAL PRACTICE Preparing for the Quizzes =

# How many packages were installed?Describe all of the field in <code>'''/etc/passwd'''</code># How many files (correct What is the command to create a user? What option to the nearest hundred) were installedcreate a home directory for that user?# How many users were What is the command to change the full name of an already-created automatically on your system (regular, admin)user?# List 3 ways that you can access your root What is the command to delete a user account? What option allows for the user's home directory to be removed as well?# What is the difference between command to create a group? What is the commands command (or steps) to include a user in a newly-created group?# What is the purpose of <code>'''su/etc/shadow''' and </code>?# What is the purpose of <code>'''su -/etc/skel''' </code>?# What is does the home directory for the user "root"term run-level mean?# How do you determine to set the host name run-level of your GNU/a Linux workstationsystem to text-based only? How to set to graphical mode?# What is the command can display to view the NIC's MAC addressstatus of running services?# What is the command is used to get start a list of running processes on your newly-installed systemservice (like httpd, or sshd)?# What is the command to copy files to your USB keystart a service?# How can Shell Scripts Can a service be used to help automate a task performed in lab1stopped and started by issuing just one command?