In OPS235, you learned how to configure a virtual private network for your '''centos1vm1''', '''centos2vm2''' and '''centos3vm3''' virtual machines. You were required to configure a static network connection for your VMs. In OPS335, you will also be setting up a static network connection for all of your VMs (which all VMs will be text-based). All of the services that we install and configure for this course '''require a working network connection'''; therefore, it is very important that you know how to configure a network connection for your VMs, whether via command line for trouble-shooting purposes, or to create a persistent (permanent) network connection that uses static IP address (as opposed to DHCP).

In OPS235, you have used the deprecated '''ifconfig''' and '''route''' commands. In this course we'll use the '''ip''' command instead. You may , so that you'll be familiar with the deprecated ifconfig and route both sets of commands, but you are expected to know the newer ip command as well.

<ol><li value="2">Run the '''ifconfig''' command on your '''c7hosthost''' machine. Check and record the IPADDR for your default (dhcp) network interface card (possibly eno1) and the virtual bridge.</li><li>Issue the '''ip''' command on your '''c7hosthost''' machine to determine the IPADDR and GATEWAY information (refer to above chart). How are the result similar or different than the ifconfig command?</li><li>Issue the ifconfig command on your VMs. what happened?</li><li>Use the '''ip''' command for your VMs to list the IPADDR and GATEWAY information.</li><li>Refer to the man pages or refer to following article [http://www.tecmint.com/ip-command-examples/ 10 Useful ip Commands] to see how to issue the above commands to create a <u>temporary</u> connection to your existing network.</ol>

For the IP address, subnet mask, default gateway, and DNS server you edit that file is contained in a directory called: '''network-scripts'''.

# From Change to the ''network-scripts'' directory (see your ''OPS335''/''OPS235''/''ULI101'' notes, issue a command to provide the full path-name of the directory: ''network-scripts''. If that command or utility does not exist, simply install it).

<li value="7">Edit the '''ifcfg-''interfacename''''' (most likely ifcfg-eth0) file for each of your VMs to use a static IP address (refer to previous OPS235 lab on networking: [ [httphttps://zenitwiki.senecaccdot.onsenecacollege.ca/wiki/index.php/OPS235_Lab_6_-_CentOS7OPS235_Lab_6#Part_4Part_3:_Configuring_VM_Network_Setup_via_Command_Line_.28centos328centos3_and_centos2.29 Network Config - CLI] ].<br> You should be configuring the BOOTPROTO ('''static''' instead of dhcp), IPADDR, PREFIX (or NETMASK), GATEWAY, HWADDR, and DNS1 for this file. Note the following information for this setup:<ul><li>Set your IPADDR for each VM with the following rules:<ol type="a"><li>Your IPADDR's third octet will use the last 2 digits in your student number.</li><li> Make certain that the 4th octet for your VMs does not start with '''1''' since that is reserved for the '''GATEWAY''' or '''DNS'''by your host machine.<br>For example, Use the forth recommended fourth octets: '''2 for vm1''', '''3 for vm2''', and '''4 for vm3'''.</li></ol></li><li>Don't forget to set the default gateway and DNS server for your VMs. You can use your host's IP address as a gateway and DNS server<br>(''libvirt'' will proxy the requests to the real DNS server).</li><li> You can refer to your previous lab to obtain information for setup of these options: [ [httphttps://zenitwiki.senecaccdot.onsenecacollege.ca/wiki/index.php/OPS335_Installation_Lab#Configuring_a_VM_host Configuring a VM Host] ]<br><br></li></ul><li>Make note of the files used and entries required and note them in your lab log-book.</li><li>Save your editing session, and then restart each VM and run the following command to ensure they still have the network configuration you set:<ul><li>'''ping''' (what is the purpose of this command?). Try to ping matrix and google from your host machine.<br>Try to ping matrix and google from each of your VM's to ensure you can reach the outside world.</li><li>'''ssh''' (into another server, like Matrix) </li></ul></li><li>After setting the network configuration for EACH VM, then either the the ifdown and ifup commands or reboot each VM, to verify that you can connect to the Internet with the new static IP network configuration. If you cannot connect to the Internet, then check the network configuration file and make corrections until you have a workable network connection for each VM from boot-up.</ol>

# '''IS THE NETWORK ENABLED?''' This is a problem more common with virtual networks than physical networks. Check in your :<br> '''VirtManager'''->'''ConnectionDetails'''->'''VirtualNetworks''' that your network is active.

==== "Run Script to Break My Network" script Connection for Troubleshooting ====

#Test your connectivity (including after a reboot of your vm1.)

<ol><li value="2">Launch your '''vm2''' machine, login to the machine, and open a shell terminal.</li><li>Use one of the commands above to check the status of your SSH server (i.e. service: ''sshd'').</li><li>Issue one of the above commands to stop of the ssh server and run a command to verify that the ssh server is no longer running.</li><li>Issue another one of the above commands to start the SSH server and to verify that it is running.</li><li>Issue a command (not listed above) to confirm that the ssh service will run upon when the vm2 server restarts(i.e. "enabled").</li></ol>

A common (if somewhat blatant ) way) to try to hack into a machine is to try to ssh as '''root''' and brute-force root's password. The root user always exists, meaning the attacker doesn't need to try guessing what user names are on your system. If they can get access to root, they can do anything. To prevent this, we will edit the configuration file for the ssh service to prevent root from ssh'ing into your host machine.

#Login to your Centos '''host ''' machine for the following steps.

#The option '''permitRootLoginPermitRootLogin''' for '''all of your VMs''' for both labs and assignments MUST be set to '''yes'''. The reason for this is that you have created a virtual network, so you have protected the host from root login, so you don't have to do the same for your VMs. Also, by allowing root login for your VM's will allow you to automatically backup your VMs to your host machine (via a crontab entry) without being prompted for a root password for each VM.

'''Note: ''' Configuration files for most services follow a very similar format. Some use an = between the parameter and its value, some require you to group certain parameters together, and most use # to be a comment. You will get lots of experience working with the configuration files for services in this course.

=== Generating a Public/Private Key Pair &amp; Sharing the Public Key ===

The public/private key pair needs to be generated on and used on your '''host''' machine (i.e. the user/machine you're connecting '''from'''). The private key is the equivalent of a <u>''password''</u> (that it is why it is considered to be <u>''private''</u> - only to be used by ''<u>one</u>'' owner). That is why the private key is stored in the owner's '''~/.ssh/''' directory.

One very common mistake that students make is to either generate the key pair for the WRONG wrong account, or copy the public key to the WRONG wrong account on the intended remote machine.

# Make certain you are in your '''host ''' machine.

# You generate Make certain you are logged on as '''root''' on your host machine.# Generate the key-pair by issuing the command:<br><source lang="bash">ssh-keygen -t rsa</source>When issuing this command, you will end up with the files: '''~/.ssh/id_rsa''' and '''~/.ss/id_rsa.pub''' (private and public keys) 

=== Sharing your Public Key on a Remote server === '''NOTE:''' When issuing this command, you will end up with the files: '''~/.ssh/id_rsa''' and '''~/.ssh/id_rsa.pub''' (private and public keys). So far, this topic is generally a repeat of OPS235 lab7.  What you may '''<u>not</u>''' know is that by using a '''"trick"''' (the ''magic'' of public key cryptography), you can SSH to a Linux machine without using a password!<br>Learning to perform this trick is <u>'''essential'''</u> in this course and in the industry in general. SSH keys are used everywhere that Linux servers are used.

A full backup is backup represents backing up of all of the files on of a systemcomputer machine (in our case, a VM). Since it may take a long time, this A full backup is NOT should be performed on a daily basisat the end of each lab or assignment working session.

In OPS235, you learned to use the command '''gzip''', '''gunzip''', and (plus'''virsh dumpxml''' / '''virsh define''' commands if backing up to external storage device like a usb key) to backup your virtual machines and the '''tar''' command as an archiving tool. In this lab, we We will expose you to use the '''dump''' and '''restore''' utilities in order same method to perform a full backups of your VMs. You should be using this utility to perform full backups of all of your VMs (both lab backup for these labs and assignment) prior to leaving your OPS335 lab sessionassignments.

#Make certain that you are logged in as '''root ''' user on your host machine.#From Refer to OPS235 lab2 on backing up your vm1 machine, make a cloned virtual machine called VMs using the '''backup-testgzip'''#On your host machine, run the following commandscommand [https:<br><source lang=bash>mkdir -p /backup/fulldump -z100 -f wiki.cdot.senecacollege.ca/backup/fullwiki/backupOPS235_Lab_2_-test /var/lib/libvirt/images/backup_CentOS7_-test.qcow2</source>_HD2#When the backup operation has been completed, issue the following command to determine the file-typePart_1:<br><source lang=bash>file /backup/full/backup_Backing_Up_Virtual_Machines OPS235 Lab2 -test</source>Backing up VMs]#What is type of file is this? Use the Make certain that you have performed a full backup for '''vm1''', '''vm2''', and '''ls -lhvm3''' command . It is recommended to create a Bash shell script to determine automate the size backing up of ALL your VMs in sequence. You can do this by running a for loop using a list for vm1, vm2, and vm3 image filepathnames.#Remove the vm you just created by issuing the follow command:<br><source lang=bash>rm /var/lib/libvirt/images/backup-test.qcow2</sourceol>#Try launching the backup-test VM from the virtual machine manager. Did it work?#Issue the following command to restore the backup-test VM by issuing the following command:<source langli value=bash"5">restore -x -f /backup/full/backup-test</source>#After restoration is complete, try launching the backup-test VM from your virtual machine manager. Were you successful?#Create the sub-directory '''/root/bin/'''</li>#<li>You should know how to create full backups of your VMs in your OPS235 course. Create a Bash shell script called :<br>'''/root/bin/mybackupfullbackup.bash''' that will backup all of your other vms (i.e. vm1, vm2, and vm3) one at a time using the '''dumpgzip''' command to your host machine into the respective directory path-namesname: '''/backup/full/vm1''', '''</backup/full/vm2''', and '''/backup/full/vm'''li>#<li>Set execute permissions, and run the shell script to verify that you shell script works.</li>#You can '''undefine the <li>It is also recommended to backup-test''' VM in the virtual machine manager to your USB key as well (qcow2 images and remove the image file for that VM in the '''xml config files).</varli></lib/libvirt/images''' directory.ol>

 An incremental backup is a backup of only files that have changed since the last backup. In your case, it may be a good idea to perform incremental backups of your '''/etc/ ''' directory for your VMs upon startup. We will be using the '''rsync''' command to perform incremental backups for all of your VMs.

<source lang=bash>mkdir -p /backup/incremental/vm1

'''NOTE:''' This command will '''NOT ''' work if '''permit root access is deniedfor your VMs''' for your sshd service configuration, so keep it off for now...

Since your host machine and VMs are '''Cronnot continuously running''' is a , ''daemon'you are not required to schedule to perform your FULL BACKUPS periodically''' (i.eeg. a program that runs in the backgroundevery week at 2:00 AM). The term ''"Cron"'' is short for '''Chronograph''' which was an old fashioned term for a '''stop watch''' Instead, it will be YOUR responsibility to run your full backup script when you complete each of your OPS335 labs, or '''timer'''when you finish your OPS335 assignment working session. The role of On the other hand, '''Cronyou will use cron to perform incremental backups''' is to run tasks periodically(eg. It can run tasks for copy updated files from the system (as rootVMs/ /etc/ directory) or for a user (including regular users).

'''Cron''' is a ''daemon'' (i.e. a program that runs in the background). The term ''"Cron"'' is short for '''Chronograph''' which was an old fashioned term for a '''stop watch''' or '''timer'''. The role of '''Cron''' is to run tasks periodically. It can run tasks for the system (as root) or for a user (including regular users). Every user has a crontab (Cron Table) which is a list of tasks they want to run periodically. You do not edit this file manually: instead, you edit this table using the command '''crontab -e'''. Once you run the command, you will get an empty file where you have to insert a line like this:

<pre>10 * * * * echo "Cron ran this job at: "`date` >> /tmp/cron.log</pre> This tells cron to run the command '''echo "Cron ran this job atPerform the following steps: "`date` > /tmp/cron.log''' at the 10th minute of every hour of every day of every month. [[crontab tutorial]]

# In {{Admon/important |Backup your host machine as root, edit your crontab and enter the line above. Modify the setting so it will run that echo command every 2 minutes.# Wait for two minutes to pass, and check the VMs!|You MUST perform a '''/tmp/cron.logfull backup''' file to see if it was created with the expected contents.<br>(You can also check of ALL of your VMs whenever you complete your '''/var/log/cronOPS335 labs''' file to see what jobs were run).# Edit or when working on your crontab to '''make automatic backupsOPS335 assignments''' of . You should be using the '''/etc''' directory from '''vm1''', '''vm2'''gzip command, and '''vm3''' into '''/backup/vm1''', '''/backup/vm2''', and '''/backup/vm3''' every hour and overwrite you should use the previous Bash shell script that you were adviced to create in order to backupall of your VMs. }}

Follow the instructions for lab 1 on blackboard. <!--===In Class SubmissionAndrew's sections===[[ImageYou may choose to:lab1_signoff.png|thumb|right|300px|Students should be prepared with * Submit screenshots of your work on Blackboard, in which case you don'''all required commands (system information) displayed in a terminal (or multiple terminals) prior t need to come to calling the instructor for signoff'''lab.]]'''Arrange evidence (command output) for each of these items on * Or come to the lab, show me your screenwork, then ask your instructor and talk to me about it. I want to review them hear what you've learned and sign off on answer any questions you have. You'll get the same grade regardless of how you choose to submit your work. Expected results of this lab's completionare:'''

::<span style="color:green;font-size:1.5em;">&#x2713;</span> FULL Display contents of backup script called: '''/root/bin/fullbackup.bash'''::<span style="color:green;font-size:1.5em;">&#x2713;</span> Full and INCREMENTAL incremental backups of your 3 VMs.::<span style="color:green;font-size:1.5em;">&#x2713;</span> You have notes in your labbook lab-book about what you've learned in this lab.::<span style="color:green;font-size:1.5em;">&#x2713;</span> Run a shell script to submit your lab:<br>:::'''Steps:''' :::*Issue the following command to download the bash shell script:<br>'''wget http://matrix.senecac.on.ca/~murray.saul/ops335/labcheck_network_backup.sh''':::*Assign execute permissions, and run the script to check your work:<br--> '''labcheck_network_backup.sh''':::*'''NOTE:''' When prompted for the network interface, use the '''virtual interface'''.