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OPS245 Lab 3 dev

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Main Objectives

*Learn to boot your ~~CentOS~~ RHEL VM into '''Single User mode''' for rescue purposes

*Create and extract '''archive''' files ('''tar''' and '''tar.gz''')

*Install applications using various methods:

'''A few common problems are:'''

*I Can't boot into Graphical Mode on my '''~~c7host~~r9host''' machine

*I Forgot My '''Regular User''' Password

*I Forgot My '''root''' Password

#Launch the VMware application.

#Select Open Virtual Machine, and select the VM called ~~c7host~~ r9host on your Solid State Drive.#Launch your '''~~c7host~~r9host''' machine, and login as as a regular user.#Boot-up your '''~~centos1~~rhel1''' VM. ''' When the Grub Boot menu appears''', press the letter <code>e</code> (for "edit").

#Using your arrow keys, scroll to next screen to '''linux''', or '''linux16''', or '''linux-efi''' command and type the word <code>single</code> as an argument after '''quiet''' (see diagram for reference) and then press <code>ctrl-x</code> to boot.

#The system should boot into text-based mode. Enter your '''root''' password.

#The procedure to reset root's password is different than shown above.

#Make certain that your ~~centos1~~ rhel1 VM that you used in Part 2 has been shutdown.#Start your ~~centos1~~ rhel1 VM and press <code>e</code> at the Grub boot menu.

#Using your arrow keys, move to '''linux''' or '''linux-efi''' command and replace the argument '''ro''' with the argument <code>rw init=/sysroot/bin/sh</code> (see diagram for reference) and then press <code>ctrl-x</code> to boot.

#The system should boot into text-based mode without prompting for root's password.

===Catastrophic Boot Problems===

:Not being able to start your '''~~c7host~~r9host''' due to '''Kernel Panic''' or some sort of '''catastrophic disk failure''' is not as easy to fix. You might be able to boot from ~~your~~ a '''~~Centos~~ LIVE DVD, open a terminal and mount the partition''' via command line and look for possible problems (setup files like '''/etc/fstab'''). '''Lab5''' will discuss more about mounting and the /etc/fstab file. The "worst-case scenario" would be to purchase a new hard disk, '''perform lab1 completely, perform lab2 to install and set-up virtualization software''', then '''restore your VM image and xml file backups''' (eg. decompressing images, issuing virsh define commands for .xml files). That is why consistently '''performing backups of ALL of your VMS at the end of each lab is absolutely essential! You have been warned!'''

'''Answer INVESTIGATION 1 observations / questions in your lab log book.'''

'''Perform the following steps:'''

#Boot up your '''~~centos3~~rhel3''' VM.

#Change your working directory to '''/usr/share/doc/sudo*'''

#Use the tar (tape archiver) command to create an archive file named "/tmp/archive1.tar" by issuing the following command: <code>tar cvf /tmp/archive1.tar .</code>

'''Perform the following steps:'''

#Remain in your '''~~centos3~~rhel3''' VM.

#Create the directory '''/tmp/extract1'''

#Change to the '''/tmp/extract1''' directory.

{| width="40%" align="right" cellpadding="10"

|- valign="top"

|colspan="2"|{{Admon/note|Internet Connection|In order for the '''~~yum~~ dnf install''' command to work you require a connection to the Internet.}}

|}

=== Part 1: Managing Software and Repositories with ~~Yum~~ DNF ===We will learn how to install software packages with the '''~~yum~~dnf''' utility. This command is useful for installing software since it automatically resolves software dependencies prior to installing the software. Upon your ~~Centos~~ RHEL OS installand registration, a link to a software repository is automatically made to allow for easy software updates.

Unfortunately, there is no guarantee that a particular software package is contained on the default repository. In order to overcome this problem, you can add other repositories that may contain the application that you wish to install.

'''Perform the following steps:'''

#Make certain that you are in your '''~~c7host~~r9host''' machine.#Issue the command: <code>sudo ~~yum~~ dnf install elinks</code>#Now issue the command: <code>~~yum~~ dnf info elinks</code>

#How can you tell if the elinks package has been installed?

#To remove the elinks package issue the command: <code>sudo ~~yum~~ dnf remove elinks</code>

# Verify that the elinks package has been removed. Also verify that the application called: '''xchat''' is not installed.

# Use the wget command to download the xchat rpm binary from the following URL:

::<code>http://mirror.centos.org/centos/7/os/x86_64/Packages/xchat-2.8.8-25.el7.x86_64.rpm</code>

::What do you think is the purpose of the numbers also contained in the filename?

<ol><li value="8">Issue the command: <code>sudo ~~yum~~ dnf localinstall xchat-2.8.8-25.el7.x86_64.rpm</code></li>

<li>Verify that the '''xchat''' command has been installed.</li>

<li>Run the xchat application.</li></ol>

<ol>

<li value="11">We will now look at how we can add different repositories to our '''~~c7host~~r9host''' machine.</li><li>Issue the following command: <code>~~yum~~ dnf repolist</code></li><li>Take a few moments to review the output. Do you see which repositories are used by the '''~~yum~~dnf''' command? Write down the repositories in your lab logbook.</li><li>View the following link to see a general listing of repositories: [ [http://wiki.centos.org/AdditionalResources/Repositories Available Repositories for Centos] ].</li><li>To add the epel repository, issue the command: <code>sudo ~~yum~~ dnf install epel-release</code></li><li>To verify that you have added the repository, you can issue the command: <code>~~yum~~ dnf repolist</code></li><li>Unused and unneeded software can present a security risk and ties up disk space needlessly. Find '''at least 4 other packages''' to remove on your ~~c7host~~ r9host machine(for example: '''sound & video''', '''games''', etc) that you're not using on your system. '''Be careful ''' to ensure that removing those packages does not also remove other software that you do need.</li>

</ol>

===Part 2: Compiling Source Code from a Downloaded Archived File===

Sometimes, some software may not be available on repositories to install with the '''~~yum~~dnf''' command. They may be available from web-pages to download, and compile. Now that you know how to create and decompress "zipped tarball archives", we will demonstrate how to install applications from websites containing these types of archives. Although this method is not as "user-friendly" as using the yum command, this method is useful if the application is NOT contained in regular software repositories...

In order to build software from source code, you must have the appropriate software development tools (such as make and gcc) and libraries (such as GTK) installed. The required tools will vary depending on the computer languages used in the software being built.

'''Perform the following steps:'''

# Remain in your '''~~c7host~~r9host''' VM, but make certain that you are logged in as a regular user (i.e. NOT root!).# Issue the command: <code>which ~~lbreakout2~~lbreakouthd</code> Is there a program called '''lbreakout2''' on your system?# Perform an Internet search for the pattern: <code>~~lbreakout2~~ lbreakouthd tar.gz</code># Go to an appropriate webpage and download a "zipped tarball" (compressed source code) for the '''~~lbreakout2~~lbreakoutHD''' game (filename should be something like: '''lbreakout2-2.6.5.tar.gz''')

#Change to the directory where you downloaded that file (most likely ''~/Download''s).

# Use the '''tar''' command to decompress the "zipped tarball" called something like (not may be exactly): '''~~lbreakout2~~lbreakouthd-21.61.51.tar.gz'''.# Change to the directory that contains that ''~~lbreakout2~~lbreakouthd'' source code.

{| width="40%" align="right" cellpadding="10"

|- valign="top"

<ol>

<li value="8">Issue the following command: <code>./configure && make</code> Most likely, you will get an '''ERROR!''' What do you think the error is telling you? </li>

<li>Issue the following command to install the files for application development by issuing the command: <code>sudo ~~yum~~ dnf groupinstall "Development Tools"</code></li>

<li>Issue the command in step 7. You should get another ERROR! What dependency is missing?</li>

<li>Issue the following command to install the library files for SQL by issuing the command: <code>sudo ~~yum~~ dnf install SDL-devel libpng-devel zlib-devel</code></li>

<li>Reissue the <code>./configure && make</code> command. Were you successful?</li>

<li>Run the command <code>~~lbreakout2~~lbreakouthd</code>. Were you successful?</li>

<li>You need to run a command to make this program available regardless of your current directory (as opposed to running command in the directory that contains the program). So, issue the command: <code>sudo make install</code></li>

<li>Run the command: <code>~~lbreakout2<~~lbreakouthd/span></code>. Did it work? Issue the command: <code>which lbreakout2</code>. What do you think that the '''make install''' command did?</li>

</ol>

'''Perform the following steps:'''

<ol>

<li> Use your '''~~c7host~~r9host''' VM for this section.</li>

<li>Open a Bash terminal and run the command:

'''Perform the Following Steps:'''

# Make certain that your '''~~c7host~~r9host''' and '''~~centos3~~rhel3''' VMs are running.# Switch to your '''~~c7host~~r9host''' machine, open a shell terminal as a regular user, and change to the directory: '''~/bin'''

# Download the Lab 3 check script: <code>wget https://raw.githubusercontent.com/OPS245/labs/main/lab3-check.bash</code>

# Give the '''lab3-check.bash''' file execute permissions (for the file owner).

# Run the shell script with <code>sudo</code>, and if any warnings appear, fix the issues noted by the script and rerun the check until you receive the "Congratulations!" message.

# Arrange proof of the following on the screen: ✓ '''~~centos3~~rhel3''':<blockquote><ul><li> Archived files '''created'''</li><li>Archive files '''restored'''</ul></blockquote>✓ '''~~c7host~~r9host''':<blockquote><ul><li> '''One repository added''' for ~~yum~~dnf</li><li>Run the '''lab3-check.bash''' script (must have all <code> OK </code> messages)</li></ul></blockquote>✓ '''Lab 3''' logbook pages filled out.

# Upload a screen of the proof from the previous step, along with the file generated by '''lab3-check.bash''', your log book, and your '''tarchiver.py''' script to blackboard.

#What does yum do that compiled source code does not?

#Other than running an installed package, what commands can you issue to verify that the package was installed?

#List the steps to remove a package via ~~yum~~ dnf command.#List the steps to install a package using the ~~yum~~ dnf command.#List the steps to add a repository to be used with ~~yum~~dnf.#What is the command to list all repositories associated with the ~~yum~~ dnf command?

#What is the command to view all repositories that have been added to-date?

#How do you use the '''sed''' command to modify text?

Jason Michael Carman

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OPS245 Lab 3 dev

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