[[Category:OPS235]]
{{Admon/caution|THIS IS AN OLD VERSION OF THE LAB|'''This is an archived version. Do not use this in your OPS235 course.'''}}
=LAB PREPARATION=
==Purpose / Objectives of Lab 1==
[[Image:hostmachine.png|thumb|right|300px|The c7host Linux server will run virtualization software to install and run 3 virtual machines (installed in lab2). ]]
You need to install a Linux OS to be a host or "platform" to install and use other Linux VMs (Virtual Machines) during this course.
The Linux OS you will be installing in this lab will be a Host Machine (''hostname''==Purpose / Objectives of Lab 4=={| width="40%" align="right" cellpadding="10"|- valign="top"|[[Image: '''c7host''') that will allow you users.png|thumb|right|150px|System administrators are required to run '''Virtualization Software''' add, remove and modify user accounts.]]|[[Image:on-off.png|thumb|right|135px|In order to create 3 separate virtual machines (perform maintenance, system administrators need to be performed in lab2). It is important know how to install this host machine correctly since other labs will depend on the stability of this host machinestop and start services for a Linux system. ]]|}
<u>Main objectives</u>:<br>:* '''Correctly install the CentOS 7 FULL INSTALL DVD''' (not LIVE DVD) on your removable hard diskThere are many other tasks that a Linux system administrator must perform other than installing Linux and installing software.
:* '''Record installation characteristics of CentOS 7 FULL INSTALL''' in a chart (contained in lab2 logbook chart) to compare with other installation methods performed in lab2A few additional tasks are user management and managing services.
:* '''Verify correct settings''' prior to proceeding with host installation stages.
<u>Main Objectives</u>:<br>:* Administer '''(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.:* '''Obtain Start and Stop services''' on a Linux server information after installationsystem.:* Display the ''' to create status of running services''' on a software asset report for later accessLinux system.
:* '''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'''.
==Minimum Required Materials==
{|cellpadding="15" width=Minimum Required Materials=={|"40%"
|- valign="top"
| [[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="40%" |{{Admon/tip|Access to Instructions for Lab1|Since you will performing a full install on your computer, you cannot use that computer to simultaneously view instructions while you perform the full install. Here are some suggestions to make this process easier:<ul> <li>'''Printout Lab1 instructions''' at home prior to performing Lab1</li> <li>'''Use a smart-phone, notebook, or netbook computer to view lab instructions''' (highly recommended)</li><li>If lab space availability is not an issue, '''use another computer termimal to view lab instructions''' while performing install</li><li>'''Follow step-by-step instructions from your OPS235 instructor''' (if demonstrated by instructor)</li></ul>|
}}
|}
==My Toolkit (CLI Reference)==
{| width="10050%" cellpadding="15"
|- valign="top"
|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 ==
Make certain to record your observations of this install in the comparison chart for '''c7host''' in your lab2 logbook.
#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.
'''Answer the Part 2 observations / questions in your lab log book.'''
== Part 3: Managing Groups ==
#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>
== Part INVESTIGATION 2: Custom Partitioning =Managing System Services and Run-levels=
{|width="40%" align="right" cellpadding="10"|- valign="top"|{{Admon/tip|Mount Points and Linux File System Types|Similar to other Operating Systems like windows '''fat''' / '''vfat''' / '''ntfs''' file system types, it Many students may think that the following topic 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 small and Journaling (used in for this lab)</li><li><b>ext2:</b> 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.senecac.on.ca/~murray.saul/ops235/installation/ installation screenshots] link for verification.]]|}#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.#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)a big deal".#Before you proceed with creating partitionsThose students may say, let's see the partitions that we need to create for our host computer:<ul><li>Primary Partitions (ext4):<ul><li>'''30GB''' for '''/''' (i.e. "root")</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 in MB (eg. 30 GB = 30000 MB) and you should multiply GB by a factor of 1024 to get the correct size.<br> (eg. '''30 GB x 1024 = 30720 MB''')<br><br>#We will now create the root (/) partition. '''Click on the add button (plus) sign'''.<br>#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.#Repeat the same steps above for the '''/home''' partition and '''/var/lib/libvirt/images''' partition. You need to type the ''/var/lib/libvirt/images'' partition since it does not appear in the drop-down menu.#Select each of the created partitions, and make certain that the file-system type How hard is changed from '''xfs''' to '''ext4'''.#Finally, add a swap partition (Mount Point: swap) for '''16 GB'''.#Check that your partition settings are correct (you can ask your instructor or lab monitor to confirm), running and then click '''Done''' to proceed.#A Summary of Changes screen will appear to show the partitioning operations that will be created. Click the '''Accept Changes''' and click stopping services?"'''Begin Installation''' in the Installation Summary screen to proceed with the installation.#Start timing your host machine installation.
The process may not be hard, but knowing how to stop, start, restart and check the status of services is absolutely critical to a Linux server. '''Aside from learning to trouble-shoot problems''' by checking the status of running services, '''understanding how to manage services is critical to help protect a Linux server from penetration''' (this term is referred to as "'''Hardening a system'''"). Sometimes it is "what we don't know" that can harm us. One key element in hardening a computer system is to disable non essential networkng services to allow IDSs ('''Intrusion Detection Systems''') to focus on a narrower range of policy violations. A Debian-based penetration testing distribution called '''Kali''' (formerly referred to as '''"BackTrax"''') allows sysadmins and security professionals to identify vulnerabilities in their computer systems, and thus improve (harden) their systems against penetration. Learning to monitor the status, enable and disable networking services underlies the '''Backtrax''' motto:<br><br>'''''"The quieter you are, then more you will hear..."'''''<br><br>
=== Part 31: Completing the Installation How do we Manage System Services? ===
{|width="40%" align="right" cellpadding="10"|- valign="top"|[[Image:completed.png|thumb|right|500px|This screen indicates We have seen that installation is complete. You should remove the install DVD and confirm Centos7 boots from your removable hard drive. ]]|}#During the installation process, you will required to create a maintaining unneeded '''root password''' (for administration access) and create packages can be a security risk'''regular user account'''. Click on '''Root Password''' and enter your root password. Think due to the unnecessary increase in the complexity 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 Similarly, it is better to log into a regular user accountalso unnecessarily hazardous, 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'''even more so, and an appropriate '''password''' (and confirm password). Click '''Done''' to finish (click twice if password is not considered to be a strong password)leave unneeded services running.#Remember to record In this host installation information in the '''installation comparison chart''' in the lab2 logbook.#When installation is completeinvestigation, you we will notice a message at the bottom of the screen stating: '''CentOS is now successfully installed and ready for you learn how to use!'''#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 appearcontrol services, then prompt the user to accept the License Information (what is the purpose of accepting the license?).#Click on '''License Information''' and '''click turn off those services that you agree to the license agreement''', click '''Done''' and then click '''Finish Configuration'''.#Click Forward we think are not necessary to enable Kdump (what is the purpose of this application?).#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>#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>#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 Internet.<br><br>#Your system automatically enables a '''screen-saver''' application which is a useful help reduce 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:<ol type="a"><li>Click on your '''username at the top right-hand screen'''</li><li>Select '''Settings''' from the drop-down menu</li><li>Click the '''Power''' icon located in the ''Settings'' Dialog Box</li><li>Change the amount of time in the '''Power Saving''' section to '''Never''' or a risks'''longer period of time'''</li><li>Close the ''Settings'' Dialog box.<br><br></li></ol>#Proceed to Investigation 2 to obtain basic information from your newly installed Centos Host machine.
#Use your '''centos2''' VM for this part.<ol> <li value="2">Use the '''man''' pages to learn about the '''service''Answer Investigation ' command.</li><li>Issue the following Linux command: <ul> <li><b><code><span style="color:#3366CC;font-size:1 observations .2em;">service --status-all</span></code></b></li> </ul> </li> <li>Note the services that are currently running.</li> <li>Use the command <b><code><span style="color:#3366CC;font-size:1.2em;">service iptables stop</span></code></b> to stop the service named '''iptables'''</li> <li>Run a command to verify that the '''iptables''' service has stopped.<br><br>'''NOTE:''' Although the service command seems to work, it is <u>'''deprecated'''</u> (all parts i.e. "out-dated:). It has been replaced by using the [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd#systemd_Command_Usage systemctl] command. This is a command based upon a newer method of starting and questionsmanaging system services called [http://zenit.senecac.on.ca/wiki/index.php/Init_vs_systemd systemd] (which replaces init - the "initialization table"). This method allows services to run more independently of each other, so that a service may be stopped without other dependent services to be stopped as well.<br><br>The most common '''systemctl''' commands are shown below (it is optional to include the filename extension '''.service''' after the service-name) :<ul><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl list-units --all'''</span> (get a listing of all service names. Can pipe to grep to list service you are interested in your lab log book)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl status service-name'''</span> (Confirm status of a service - running or not-running)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl stop service-name'''</span> (stop a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl start service-name'''</span> (start a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl restart service-name'''</span> (restart a service)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl enable service-name'''</span> (enable service so service runs upon system startup)</li><li><span style="font-family:courier;font-size:1.2em;font-weight:bold;">'''systemctl disable service-name'''</span> (disable service so it does NOT run upon system startup)<br><br></li></ul></li> <li>If you reboot now - the iptables service will be turned back on. We don't want it on though, it causes students headaches.<br>To turn it off permanently we need to use the '''systemctl''' command:<b><code><span style="color:#3366CC;font-size:1.2em;">systemctl disable iptables</span></code></b><br>(the '''chkconfig''' command used to be the way to enble/disable services, but is now deprecated).</li> <li>Use the '''systemctl''' command to verify that the '''iptables''' service is no longer running ('''hint:''' issue command, and pipe to grep "'''iptables'''"). <li>Reboot and confirm that it's no longer running.</li></ol>
'''Answer Part 1 observations / questions in your lab log book.'''
=INVESTIGATION ==Part 2: OBTAINING HOST MACHINE SYSTEM INFORMATIONHow do we Manage Runlevels?===
Running servers in graphical mode will make your system most likely to be penetrated. The X-windows framework can be vulnerable to attacks when these servers are connected to the Internet. This is why when you install server versions of Linux, they work in text-based mode only. Desktop versions of Linux are then installed on workstations (working in graphical mode) that connect to the server (for security reasons).
==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.
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{{Admon/important|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>}}
|}
Navigate through your Graphical CentOS system, '''locate and run a terminal program (in order to issue Linux commands). Issue and record the commands used and the output generated in each of the following steps:'''
#With older (ancient) versions of Linux, a user once may have been allowed to login to their graphical Linux system using '''root''' as their user-name and their root password. This has been determined to be a security risk and that option has been removed with many or all Linux operating systems.
#Therefore, from this point onwards, you will be logging into your regular user account instead and issuing a command to login as the ''root'' user.
#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/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 installing /var/log/anaconda/anaconda.packaging.log | wc -l'''</span></code></b>
<ol>
<li value="8">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>
</ol>
::<b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a'''</span></code></b>
::<b><code><span style="color:#3366CC;font-size:1.2em;">rpm -q -a | wc -l'''</span></code></b>
::<b><code><span style="color:#3366CC;font-size:1.2em;">rpm -qa | wc -l'''</span></code></b>
<ol>
<li value="10">The <code>'''-q'''</code> option means query, and the <code>'''-a'''</code> option means all (in other words, query all installed software packages). Did you get the same number of packages from the above two methods?</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>install.log</code>), you can list all the files that were installed from the package by using the following command:</li>
</ol>
::<b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">rpm -q -l gedit</span></code></b>
<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>
<ol>
<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>
</ol>
==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.'''
= INVESTIGATION 3: LOOKING AHEAD =
==Part 1: Disable SELinux and Perform Software UpdatesAutomating Routine Tasks (Shell Scripting)==
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{{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> 1) echo "You win a car!" ;;<br> 2) echo "You win a good thing, if you take care bag of it dirt!" ;;<br> *) echo "Not a valid entry"<br> exit 1 ;;<br>esac''<br><br>''read -p "enter a single digit: " digit<br>case $digit in<br> [0-9]) echo "Your single digit is: $digit" ;;<br> *) echo "not a valid single digit"<br> exit 1 ;;<br>esac''<br><br></li><li>'''The getopts function:'''<br><br></li></ul>The getopts function allows the shell scripter to create scripts that accept options (like options for Linux commands). This provides the Linux administrator with scripts that provide more flexibility and know how it worksversatility. A built-in function called '''getopts''' (i.e. For this course it get command options) is strongly recommended that you used in conjunction with a '''while''' loop and a '''case'''disable SELinux by defaultstatement to carry out actions based on if certain options are present when the shell script is run. The variable '''$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> case $name in<br> a) echo "Action for option \"a\"" ;;<br> b) echo "Action for option \"b\"" ;;<br> c) echo "Action for option \"c\""<br> echo Value is: $OPTARG" ;;<br> :) echo "Error: You need text after -c option"<br> exit 1 ;;<br> \?) echo "Error: Incorrect option"<br> exit 1 ;;<br>esac''<br>done<br><br>}}
|}
# Disabling SELinux is quite simple, just edit the file '''/etc/selinux/config''' and set SELINUX to disabled.
# Add additional text regarding disabling SELinux.
#The CentOS software is updated frequently to add features, fix bugs, and upgrade security. Perform a system update to get the latest versions of the packages installed: Start the Firefox web browser, turn off popup window blocking (select '''Edit''', '''Preferences''', then select the '''Content''' tab and uncheck the box to '''Block Popups'''), then return to your web-browser, load a page, and when prompted, login to SeneNET.
#Make certain that you have at least 30 minutes available in your lab-time prior to performing a system update. Never abort a system update since it may damage your system files and render your host mahcine inoperable!
#Open a terminal and type <b><code><span style="color:#3366CC;font-size:1.2em;">su</span></code></b> to start a shell as root. Enter the command <b><code><span style=" pointer-events:none;cursor:default;color:#3366CC;font-size:1.2em;">yum update</span></code></b> This will download and install all of the packages that have been updated since the installation DVD image was created. If you complete this command at Seneca it should run quite fast as Seneca College hosts a CentOS Repository mirror (a copy of all of the current CentOS packages, on a local web server).
We will now use shell scripting to help automate the task for a Linux adminstrator to create regular user accounts.
==Part 2: Automating Routine Tasks (Shell Scripting)==
{|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 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: using your '''ENVIRONMENTc7host''' (egmachine for this section. $USER)#Download, '''user-defined''' ($varName)study, and '''positional parameters''' (eg. $1, $2... containing arguments after run the following shell script or by using set command (eg. '''set $(ls)''' ). Using dollar sign ('''$''') in front of variable expands Issue the value assigned.command:<br><brb></licode><li>'''Command Substitutionspan style=" pointer-events:'''<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 $USER = "root") . The '''$?''' special shell variable stores the result (zero if true, non-zero if false)on. 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/ '''ifuser-else''' / '''if-elif-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 = "root" ]''<br>''Try to understand what these Bash Shell scripts do, and then''<br> ''echo "You must be run the script as root" >&2''<br> ''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 ]'/home'<br>''then''<br> ''echo "retire"''<br>''else''<br> ''echo "don't retire"''<br>''fi''<br><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></ul>}}|}You may have learned about creating and running Bash Shell Scripts in your ULI101 course. Shell scripts help Linux users and system administrators directory 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 to view Shell Scripting Tips which are located on the right-hand sideconfirm.
If you require <u>'''additional practice'''</u> in creating shell scripts and using the vi text editor, run the commands in your '''Matrix''' account: <ul><li>'''/home/murray.saul/vi-tutorial'''</li><li>'''/home/murray.saul/scripting-1'''</li></ul>
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.
# Make certain to log out of your root account and remain as a regular user.
# Open a Shell terminal and use 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.
# 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>
<ol><li value="3">Open a Bash shell terminal and login as root.</li><li>Use the wget command to download the input file called user-data.txt by issuing the command:<br><b><code><span style="color:#3366CC;font-size:1.2em;">wget https://scs.senecac.on.ca/~murray.saul/user-data.txt</span></code></b></li><li>View the contents on the user-data.txt file to confirm there are 3 fields (username, fullname, and e-mail address)which are separated by the colon (:) symbol.<li><li>Use 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;">createUsers.bash</span></code></b> in /root's home directory.</li><li>Enter the following text content into your text-editing session:</li></ol>
<code style="color:#3366CC;font-family:courier;font-size:.9em;margin-left:20px;">
<br>
#!/bin/bash<br>
<br>
# createUsers.bash<br>
# Purpose: Generates a batch of user accounts (user data stored in a text file)<br>
#<br># USAGE: /root/createUsers.bash [-i {input-path}] <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 [ $USER PWD != "/root" ] # only runs if logged in as root's home directory<br>then<br> echo "You must be logged in as root's home directory." >&2<br>
exit 1<br>
fi<br>
if [ "$#" -eq 0 ] # if no arguments after command<br>
then<br>
echo "You must enter an argument" >&2<br>
echo "USAGE: $0 [-i {input-path}]" >&2<br>
exit 2<br>
fi<br>
</code>
<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>
<br>
<code style="color:#3366CC;font-family:courier;font-size:.9em;">
# Create report title<br>
<br>
echo outputFlag="SYSTEM REPORTn" <br>while getopts i: name<br> /root/report.txtdo<br> case $name in<br> i) inputFile=$OPTARG ;;<br> :) echo "DateError: $(date +'%A %B %d, %Y (%H:%M:%p)')You need text after options requiring text" <br> exit 1 ;;<br> /root/report.txt \?) echo "Error: Incorrect option"<br>echo exit 1 ;;<br> esac<br> /root/report.txtdone<br>
</code>
<ol><li value="6">Save your editing session, but remain in the text editor.</li><li>The code displayed below uses logic to exit the script if the input file does not exist. Command substitution is used to store each line of the input file as a positional parameter. There is one subtle problem here: The full names of the users contain spaces which can create havoc when trying to set each line as a separate positional parameter. In this case the sed command is used to convert spaces to plus signs (+), which will be converted back later. Finally, a '''for''' loop is used to create each account ('''useradd''') and mail the user their account information ('''mail'''). Add the following code:</li></ol>
<br>
<code style="color:#3366CC;font-family:courier;font-size:.9em;">
<br>
if [ ! -f $inputFile ]<br>
then<br>
echo "The file pathname \"$inputFile\" is empty or does not exist" >&2<br>
exit 2<br>
fi<br>
<br>
set $(sed 's/ /+/g' $inputFile) # temporarily convert spaces to + for storing lines as positional parameters<br>
<br>
for x<olbr>do<li valuebr> userPassWd=$(date | md5sum | cut -d"8"-f1)<br>Save and run the bash shell script. View the contents of the file called useradd -m -c "$(echo $x | cut -d":" -f2 | sed 's/+/ /g''report.txt''' that was generated )" -p $userPassWd $(I hope you are using the up arrow key to issue previously issued commands in order to save time!echo $x | cut -d":" -f1). Notice how the redirection symbol <br>>nbsp; is used at the beginning of the report, and then the other redirection symbol >nbsp;> is used to help mail -s "Server Account Information" $(echo $x | cut -d"grow:" the report with the other content.-f3) <<+</libr> Here is your server account information:<libr>The only remaining content of the report would be the system information servername: myserver. We can use a shell scripting trick called "command substitution" $( senecac.on. ) in order place results from an command to be used by another command ca<br> username: $(like echo$x | cut -d":" -f1). Re-edit the shell script and add the following code at the bottom of the shell script file<br> password:$userPassWd<br> Regards,<br> IT Department<br>+</libr>done</olbr>
<br>
<code style="color:#3366CC;fontecho -family:courier;font-size:.9em;e ">echo >> /root/report.txt<br>echo \n\nAccounts have been created\n\n"Hostname: $(hostname)" >> /root/report.txt<br>echo >> /root/report.txt<br>echo "Kernel Version: $(uname -rv)" >> /root/report.txt<br>echo >> /root/report.txtexit 0<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:<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>
<ol>
<li value="8">Save, set permissions, and then run that shell script for the input text file '''user-data.txt'''. Did it work? Try running the script without an argument - What did it do? </li><li>You have completed lab4. Proceed to Completing The Lab, and follow the instructions for "lab sign-off".</li></ol>
'''Answer Investigation 3 observations / questions in your lab log book.'''
'''Answer the Investigation 3 observations = LAB 4 SIGN-OFF (SHOW INSTRUCTOR) ={{Admon/ questions in important|If you have successfully completed this lab, make a new backup of your lab log bookvirtual machines as well as your host machine.'''|}}
'''Arrange proof of the following on the screen:'''
<ol><li><span style= LAB 1 SIGN"color:green;font-OFF (SHOW INSTRUCTOR) =[[Imagesize:lab1_signoff1.png|thumb|right|500px|Students should be prepared with a5em;">✓</span> '''centos1''' VM:<blockquote><ul><li>Account created on '''centos1''ll required commands ' VM</li><li> List contents of '''/etc/group''' file (system informationops235 group) displayed in a terminal </li><li>List contents of '''/etc/passwd''' file (or multiple terminalscreated accounts) prior to calling the instructor for signoff</li></ul></blockquote><li><span style="color:green;font-size:1.5em;">✓</span> '''centos2''' VM:<blockquote><ul><li>Display current run-level status on '''centos2'''VM</li></ul></blockquote></li></li><li><span style="color:green;font-size:1.]]5em;">✓</span>'''c7host'Arrange evidence (command output) for each '' machine<blockquote><ul><li>Creation of these items on your screen, then ask your instructor to review them and sign off on the labbash shell script called '''createUsers.bash'''s completion</li></ul></blockquote></li><li><span style="color:green;font-size:1.5em;">✓</span> '''Lab4''' log-book filled out.</li></ol>
::<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> Contents of '''/etc/fstab''' file confirming partitions file types are '''ext4'''
::<span style="color:green;font-size:1.5em;">✓</span> Correct '''IP address''' and '''MAC address'''
::<span style="color:green;font-size:1.5em;">✓</span> '''Default route (gateway)'''
::<span style="color:green;font-size:1.5em;">✓</span> '''DNS name server IP Address'''
::<span style="color:green;font-size:1.5em;">✓</span> Contents of your '''report.bash''' shell script
::<span style="color:green;font-size:1.5em;">✓</span> proof of '''yum update''' performed on c7host
::<span style="color:green;font-size:1.5em;">✓</span> '''lab1 notes''' <u>and</u> '''first column of Comparison Chart in lab2'''.
= ADDITIONAL PRACTICE = Practice For Quizzes, Tests, Midterm & Final Exam ==
# 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?
[[Category:OPS235]]
[[Category:OPS235 Labs]]