Difference between revisions of "OPS335 Lab 5"

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[[Category:OPS335]][[Category:OPS335 Labs]]
 
[[Category:OPS335]][[Category:OPS335 Labs]]
  
== OBJECTIVE & PREPARATION==
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==OBJECTIVE & PREPARATION==
  
In this lab, we will look at several separate technologies that are used with the Apache web server to install, configure and run web applications.
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According to the samba.org website:
  
The basic purpose of the Apache web server is to serve text pages, images, and other static files. You can format those web-pages to appear nice, but they would lack dynamic functionality (i.e. the ability to change colors or font-size when the mouse moves over a link, button, etc). In other words using Apache web-server as a sole application would not make your web-pages more interesting.
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''"Samba is the standard Windows interoperability suite of programs for Linux and Unix. Samba is Free Software licensed under the GNU General Public License, the Samba project is a member of the Software Freedom Conservancy."''
  
If we want to add more features for our web-page (eg. dynamic functionality, security, e-commerce, etc), your webserver would need additional help. To provide additional help requires several resources - more than just the web server itself. A popular acronym to represent these foundations and servers is referred to as '''LAMP'''. It stands for '''Linux''', '''Apache''', '''MySQL''', and '''PHP''' (or ''Python'').
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Although a Samba server can provide many features such as printer sharing and backups, this lab's primary focus is to set up a Samba server on a Linux server in order to allow MS Windows users to share common files from the Linux's Samba server.
  
In your previous OPS235 course, your second assignment may have required you setup a similar series of services in order to run a Wiki on one of your virtual machines. In this lab, we will set up another example of a '''"LAMP solution"''' that will allow the user to run webmail in a web-browser to send and receive e-mail messages.
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This lab will first install, setup, and enable a Samba server. Then users will access files on the Linux Samba server from Linux and Windows client machines (both graphically and command line).
  
[[Image:lamp.png|thumb|right|300px|To provide additional help make your web resource more dynamic (for web apps such as webmail) several services are also required. A popular acronym to represent these foundations and servers is referred to as '''LAMP'''. It stands for '''Linux''', '''Apache''', '''MySQL''', and '''PHP''' (or ''Python'').<br><br>Image by Shmuel Csaba Otto Traian,<br>https://commons.wikimedia.org/w/index.php?curid=28224098)<br>(via: [http://creativecommons.org/licenses/by-sa/3.0 Commons Attribution-Share Alike 3.0]) ]]
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=== Online Resources===
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* (Course Notes on Samba Server)
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*[http://www.tomsitpro.com/articles/linux-server-configuration-guide-book-excerpt,2-777-2.html Samba Server Setup] (Simple setup guide for samba server]
  
=== Online Resources===
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==INVESTIGATION 1: INSTALLING &amp; CONFIGURING A SAMBA SERVER==
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 +
In this investigation, we will set up a '''Samba server''' on our '''VM2''' machine. We will first install, configure and enable the samba server on our virtual machine, and then we will quickly test to see if the Samba server works.
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 +
 
 +
'''Perform the following steps:'''
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 +
#Make certain that both your '''VM1''' and '''VM2''' machines are running.
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#Switch to your '''VM2''' machine as the '''root''' user.
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#Issue the following Linux command to install Samba server utlity:<br>'''yum install samba samba-client'''<br>
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#Copy the file '''/etc/samba/smb.conf''' to another filename by issuing the following command:<br>'''cp /etc/samba/smb.conf /etc/samba/smb.conf.original'''
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#Clear the contents of the configuration file by running '''cat /dev/null >  /etc/samba/smb.conf'''
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#Edit '''/etc/samba/smb.conf''' so that the file that contains the following lines:
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[global]
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workgroup = WORKGROUP
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server string = "put your real name here without the quotes"
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encrypt passwords = yes
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security = user
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passdb backend = tdbsam
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[home]
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comment = "put your real name here without the quotes"
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path = /home/<yourSenecaID>
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public = no
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writable = yes
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printable = no
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create mask = 0765
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 +
[homes]
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comment = automatic home share
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public = no
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writable = yes
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printable = no
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create mask = 0765
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browseable = no
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<ol><li value="3">Append (add) the following parameter to the bottom of the '''[global] section''' that will limit access to the share so that only machines in your virtual network will be able to access it:</li></ol>
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hosts allow = 192.168.x. 127.0.0.1
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<ol><li value="4">Append (add) the following parameter to the '''[home] section''' so that only your user account can access that share:</li></ol>
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valid users = <yourSenecaID>
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<ol><li value="5">Create a Samba account and password for yourSenecaID by issuing the following command:<br>'''smbpasswd -a <yourSenecaID>'''</li></ol>
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{{Admon/tip|Changing Existing Samba Account Passwords|If you need to change a user's existing Samba account password, you can issue the following command as root: '''smbpasswd username'''.}}
  
* (Course Notes on the Apache Web Server)
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<ol><li value="6">Confirm the user you created has been added using the following command:<br>'''pdbedit -L -v'''</li><li>Test and review your configuration with the command:<br>'''testparm'''</li><li>Use the '''systemctl''' command to start the smb.service and enable the service to run on boot-up</li><li>Since we set SELinux to enforcing, we will need to tell it to allow samba access to home directories: '''setsebool -P samba_enable_home_dirs 1'''</li><li>Use the '''ss -nautp''' command to see with port Samba is running on.</li><li>Use the information in the previous step to modify the firewall on VM2 machine to allow samba traffic.</li><li>Test to see that you can connect to your Samba server (locally) by issuing the following command:<br>'''smbclient -U <yourSenecaID> -L 127.0.0.1'''</li><li>When prompted, enter your Samba account password.</li><li>The output from that issued command show appear similar to example displayed below:</li></ol>
* [http://www.hitmill.com/computers/apache.htm Apache Resources]
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* [http://www.liquidweb.com/kb/how-to-install-apache-on-centos-7/ Installing Apache Webserver on Centos7]
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Sharename      Type      Comment
* [http://www.w3schools.com/php/default.asp PHP Tutorial] (w3schools.com)
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---------      ----      -------
* [http://www.w3schools.com/sql/ MySQL / SQL Language Resources] (w3schools.com)
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home            Disk      Your Name
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IPC$            IPC      IPC Service ("Your Name")
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Domain=[WORKGROUP] OS=[Windows 6.1] Server=[Samba 4.2.3]
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Server                Comment
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------                -------
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WorkGroup            Master
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---------            ------
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<ol><li value="13">To access the Samba client shell on your local Samba share, issue the following command:<br>'''smbclient '\\127.0.0.1\home' -U <yourSenecaID>'''</li><li>Enter your Samba account password.</li><li>Issue the help command to note common commands (''dir'', ''cd'', ''ls'', ''put'', ''get''). Note how similar they are to ''sftp'' commands.</li><li>Enter '''exit''' to terminal your local Samba session.</li></ol>
  
== INVESTIGATION 1: SETTING UP A LAMP SOLUTION ==
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You can use smbclient to access, browse and share files within other Linux and Windows servers using a variety of tools which will be demonstrated in Investigations 2 and 3.
  
=== Install, Configure & Run a Webserver (Apache) ===
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'''Record steps, commands, and your observations in INVESTIGATION 1 in your OPS335 lab log-book'''
  
Next we need to install, configure and run a webserver on one of our Linux VMs.
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==INVESTIGATION 2: CONNECTING TO A LINUX SMB SERVER FROM A LINUX CLIENT==
  
{{Admon/tip |Apache Webserver Resources|Apache web-server configuration can be a very complex topic (covering an entire course!). Although this lab focuses only on one small application of a web-server, you can refer to the following link to refer to additional configuration help: [http://www.hitmill.com/computers/apache.htm Apache Resources].}}
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In this investigation you will explore some of the different ways to access a shared directory from a Linux client machine (VM1).
  
'''Perform the following steps:'''
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=== Installing and Using smbclient ===
  
#Make certain you are in your '''VM1''' machine.
 
#Install the Apache package (the name of the package is: '''httpd''').
 
#Start the httpd service, and enable this service to start automatically upon system startup.
 
#Using a text browser such as lynx on vm1 go to localhost. You should get the "Fedora Test Page" which indicates your web server is running on the local virtual machine.
 
#Make certain to configure your firewall to allow access to the httpd service (i.e. the Apache serves HTTP traffic which goes over TCP port '''80''') and to update the firewall_restore script to include it.
 
#Open a web-browser in your '''host''' machine and enter the following URL: '''vm1.youruserid.org'''.<br />If you setup your Apache webserver correctly, you should be able to view the Apache Test page.
 
#Although we will not be exploring webservers in depth, we will have you create a simple webpage for testing purposes, then later setup a web resource for webmail.
 
#The term '''DocumentRoot''' specifies where the Apache webserver will search for documents to serve. Create the file '''index.html''' in your '''DocumentRoot''' directory with the following contents (replace the date with the current one):<br><source>Hello, this is a web page on vm1.yourid.org and the current time is Mar 28 22:16:27 EDT 2016!</source>
 
<ol><li value="9">If you refresh your web-browser page in your browser, you should see the contents of your ''index.html'' document. If you wish, you can specify the filename index.html in the address, but it is not necessary, since the file index.html is automatically loaded by default when the URL refers to that directory containing that file.</li></ol>
 
  
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'''Perform the following steps on your VM1'''
  
{{Admon/tip |Using the '''index.html''' file|It is considered to be a "best practice" to create '''index.html''' files for newly-created subdirectories within the '''DocumentRoot''' (or users' '''public_html''' directories) to force a display of a web-page, instead of viewing the directories "index" listing of files (from "curious eyes"): that is why the name of the file is called ''"index.html"''.}}
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#Install the '''samba-client''' and '''cifs-utils''' packages.
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#Use the "smbclient" command in a terminal window.<source>
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smbclient '\\vm2\home' -U <yourSenecaID></source>
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#After entering your password you should get a prompt similar to:<source>
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smb: \></source>
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#Enter the ls command to see a list of the files in your home directory:<source>
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smb: \> ls</source>
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#Once you have access to the directory use the get and put commands (similar to ftp) to move files.
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#When you are finished close the connection.
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# Try again using '''[homes]''' share instead
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<source>
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smbclient '\\vm2\homes' -U <yourSenecaID></source>
  
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Did it work even though you didn't specify '''path=/home/<yourSenecaID>''' under '''[homes]'''?
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<br /><br />
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Note that this tool only gave temporary access with a limited set of commands.
  
<ol><li value="10">Refresh your web-page by issuing the keycombination: '''ctrl-r'''. Notice that the time doesn't change as you refresh the page. This indicates that the page is static (not dynamic) indicating that the page does not change (i.e. boring!).</li></ol>
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=== Using 'mount -t cifs' ===
  
=== Creating a PHP Script ===
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Instead of always having to use the smbclient command to connect to your network share, you can have the share automatically mounted upon your file server boot-up.
  
In order to allow us to run a webserver application in a web-browser, we need a scripting language that will allow the web-browser to function dynamically (i.e. being able to change frequently, as opposed to being "static" or unchanging). In this section, we will demonstrate how a scripting language (PHP) can be used for the web-browser to react in a more dynamic fashion.
 
  
{{Admon/tip |PHP Scripting Language|PHP code is considered to be a language that runs on the web-server (i.e. "server-side programming"). PHP code can be embedded in an HTML document (HTML code), and use the resources on the "server-side" to make the web document or resource more dynamic (eg. database access, etc). Although it is not the purpose of this course to learn about and create PHP documents, here is a quick resource on PHP: [http://www.w3schools.com/php/default.asp PHP Tutorial]}}
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'''Perform the following steps on your VM1'''
  
'''Perform the following steps:'''
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#Issue the following commands to create a mount-point and to mount your home directory from your vm2 machine:<source>
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mkdir /tmp/vm2-home
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mount -t cifs //vm2/home /tmp/vm2-home -o username=<yourSenecaID>
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ls /tmp/vm2-home</source>
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#Create a file in that directory, then switch to '''vm2''' to confirm that it was created.
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#Use umount on '''vm1''' to unmount that directory.
  
#Copy the '''index.html''' file to '''index.php''' and modify it to contain:<br><source>Hello, this is a web page on vm1.yourid.org and the current time is <?php system("date"); ?>!</source>
 
  
<ol><li value="2">On your host machine, again refresh your web-browser. Notice that in a web browser the ''index.php'' file isn't treated as a default page and the contents don't contain the date, but instead are displaying the text in the php code you entered into the index.php file (refer to above code).</li>
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Note that this tool would leave the directory mounted until the machine rebooted or it was manually unmounted. It would also allow other users access to the directory, as it effectively became part of the local filesystem.  It could even be added to fstab to be mounted on boot (though this would require another configuration file we don't cover).
<li>The reason this occurs is that the PHP interpreter hasn't been installed on your vm by default.</li>
 
<li>Install the php package on your vm1 machine, and restart your webserver. NOTE: The php package comes with a working default Apache configuration so you don't need to enable it manually.</li>
 
<li>Refresh the webpage for your web-browser on your host machine. You should now notice that you see the date instead of the call to the date command. Refresh your webpage several times to see how the time changes. This is simply a "trivial example" of dynamic web content does it does provide a simple demonstration of how scripting languages can be used to create more dynamic webpages.</li>
 
</ol>
 
  
=== Controlling Access to Pages ===
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=== Using Nautilus to browse Samba shares ===
  
For security, it is important to allow access to general areas of your webpage, but also limit access to other sub-directories that contain other webpages or documents. Penetration Tester or hackers may be able to navigate your file systems within your html directory to obtain unauthorised information.  
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Instead of accessing your file share via CLI, you can also connect, navigate and access your file share via a graphical application such as a file browser or a web-browser.
  
There are many common-sense safeguards, such as creating an index.html file in your default directory that will display a webpage instead of the directory index. On the other hand, there are also safeguards that you can setup to provide additional protection to your data on your web server.
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'''Perform the following steps on your HOST machine:'''
  
'''Perform the following steps:'''
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#Install the '''samba-client''' and '''cifs-utils''' packages.
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#Use the "Places" menu from the desktop and open 'Browse Network'.
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#From the menu in the side-bar of the files tool, choose 'Other Locations'.
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#In the bar titled 'Connect to Server' enter '''smb://vm2/home''' as the location, and enter your samba password in the prompt<br>(Where vm2 is the name of the server, and home is the name of the directory it is sharing).
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#After you have checked that you can access your files, unmount the share by right-clicking its icon in the side-bar and clicking 'Unmount'.
  
# As the root user on your gateway/host, try to forward incoming http connections that arrive on your host to the web server on vm1. Use an iptables command something like this:<br><source>iptables -t nat -A PREROUTING -i *yourinterface* -p tcp --dport 80 -j DNAT --to 192.168.X.2</source>
 
# You will also need to create a rule in the FORWARD chain in the default table to accept connections to port 80.
 
# To test this setup you'll need to ask a classmate on another PC to try to use a browser to view your web page. That person will have to enter your host's external interface IP number in their browser's address window. Have that person view both '''index.html''' and '''index.php'''
 
# Create a new directory inside your '''DocumentRoot''' and move index.php inside it.
 
# Have your partner view both files again.<br><br>You will now modify the settings on the web-server to prevent machines outside our network from accessing the private directory.<br><br>
 
# Add the following directory statement to your apache configuration (making sure to replace the X with your own network octet):<source>
 
<Directory "/var/www/html/private">
 
  AllowOverride None
 
  Require ip 192.168.X.0/24
 
</Directory>
 
</source>
 
  
This sets up separate rules and access permissions for that subdirectory. Your partner should no longer be able to access any pages in the private directory (or any sub-directories of it), but your other internal machines (including your host) should still have access.
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:You can also use a web browser with support for the SMB protocol such as Konqueror (Note that firefox does not have such support)
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=== Install, Configure and Run MySQL Database Server ===
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<ol><li value="6">If Konqueror is not installed then install it with the command: <source>
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yum install kdebase</source></li>
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<li>Start Konqueror, the web/file browser, and in the address bar enter the following:<br>'''smb://vm2/home'''</li>
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<li>Enter your username and password when prompted.</li>
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<li>Double click on a file you have some text in.</li>
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<li>Open it with gedit, make some changes, and save it.</li>
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<li>When prompted, choose to upload the file.</li>
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<li>Close Konqueror.</li>
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<li>cat the file on your VM2 to ensure the changes were properly uploaded.</li>
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</ol>
  
We complete the last piece of the puzzle by installing, configuring and running a database server to support your webmail application that will be installed and setup in a later lab.
 
  
MySQL is used to allow storage and retrieval of structured data. SQL is a command language (used by scripting languages such as PHP) to allow programmers to access databases contained within a server (or other servers via a network) to be used within web-based applications via the web-browser.
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'''Record steps, commands, and your observations from this INVESTIGATION in your OPS335 lab log-book'''
  
We won't spend much time learning the details of MySQL configuration but you need a basic server set up. You may remember when setting up MySQL from OPS235 - it is basically the same concept.
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==INVESTIGATION 3: CONNECTING TO A SAMBA SERVER FROM A WINDOWS CLIENT==
  
{{Admon/tip |MySQL / SQL Language Resources|Again, MySQL can be a complex topic: Seneca has an entire course that concentrates on using SQL commands! Here is a link to MySQL / SQL Language resources: [http://www.w3schools.com/sql/ MySQL / SQL Language Resources].}}
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This investigation will configure your VM2 machine to act as a Samba File server to allow Windows OS Users access to the Linux Samba server files.
  
'''Perform the following steps:'''
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===Accessing Files on a Linux Samba Server via Windows Explorer ===
  
#Install '''mariadb-server'''.<br /><br />  The MySQL and MariaDB are actually two <u>separate</u> projects run by different groups, yet they are compatible; therefore, you can use documentation from one to configure the other. <br><br>
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With some additional "tweaking" to your Linux Samba server configuration file, you should be able to access files on that file from a Windows machine on the same network. You will be creating a Samba share for your home directory of your regular user account.
#'''NOTE:''' When installing mariadb, make certain that you have not just the '''client''' but also the '''server software'''.
 
#When you start the MySQL service, check the system log file for instructions regarding how to set the root password. Even though we will not configure our MySQL service to be accessible over the network, it is accepted as a "best practice" configuring for network access for each MySQL installation.
 
#Note that the MySQL service has two root passwords:<ul><li>For the localhost</li><li>For external requests</li></ul>
 
#Refer to the log file to learn how to run the two commands in order to generate the appropriate passwords.<br><br>NOTE: Use a password you make up yourself, but do <u>not</u> generate a secret password, since you will be storing that password in a plain text file for later reference.
 
#Start the service and ensure that it will start automatically every time the machine boots.
 
  
=== Test Connection to MySQL Database Server ===
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'''Perform the following tasks:'''
  
While the web server (with php), and MySQL server may be working individually, we need to ensure that they can connect to each other. Since this test will involve storing the database password in a plain-text html file, we want to make sure no one else can access it.
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# Make certain that your '''VM2''' machine is running, is still allowing samba traffic through the firewall, and is still running the samba service.
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# If you are using a drive in the removable bay, power up a Windows system in the lab and login.  If you are using a USB SSD drive, use the Windows machine you are already on.
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# Add the prerouting and forwarding rules to your host's iptables necessary to redirect samba traffic from outside your network to your VM 2.
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# Modify the hosts allow setting on your '''vm2''' to also accept connections from the windows machine you are using.
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# Open the Windows File Explorer application.
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# At the top of the application, enter the following:<br>'''\\IPADDR_OF_HOST_MACHINE\home'''
  
'''Perform the following steps:'''
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{| width="40%" align="right" cellpadding="10"
  
# Modify the Directory statement for your private directory to prevent any machine other than your vm1 from accessing it.
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|- valign="top"
# Re-start the web-server and try to access the page from another machine.  Make sure that you can '''not''' do so before you continue.
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|
# Install the '''php-mysql''' module so that the installation of php your web server is using can execute sql statements. You will have to restart the service after installing it.
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[[Image:samba-login.png|thumb|right|300px|You will be prompted (once only) for the Samba user-name and password for your '''VM2''' machine). ]]
#Modify the index.php page in your private directory to match the code below.  This will test that your web server can connect to the database (replace the user, password, and database with values appropriate for your machine):<br><source>
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|
<?php
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[[Image:samba3-map-drive.png|thumb|right|300px|You can create a '''mapped network drive (z:)''' for your Linux Samba server network share). ]]
$mysqli = new mysqli("localhost", "user", "password", "database");
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|}
if ($mysqli->connect_errno) {
 
    echo "Failed to connect to MySQL: (" . $mysqli->connect_errno . ") " . $mysqli->connect_error;
 
}
 
echo $mysqli->host_info . "\n";
 
?>
 
</source>
 
#Once that page shows a successful connection on your VM ('''Localhost via UNIX socket''') this step is complete.
 
  
You have now established that the web server is able to run code which can interract with the database. This will allow dynamic pages to make use of information stored there when providing resources to your users.
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<ol><li value="5"> You will be prompted to enter your samba username and password (one time only). Refer to diagram on right.<br><br>'''NOTE:''' It may take approximately 30 seconds to display the file contents.<br><br></li><li>Were you successful? You should have received an error stating the your credentials are incorrect.  You will notice that it adds SENEDS to the beginning of your user name, as the Seneca machine is pre-configured to be part of that workgroup.</li><li>Change the workgroup parameter in smb.conf on VM2 to match the seneca domain SENEDS, and try to connect again.</li><li>Were you successful? If not, try to troubleshoot the problem first, then ask your lab assistant or instructor for assistance.</li><li>Close the Windows File Explorer application window.</li><li>Click on the '''START''' menu, and click on '''This PC'''.</li><li>Click on the Map Network Drive button, and create a '''mapped network drive''' (called it drive '''Z:''') which is a Samba share of your VM2 machine for the home directory.</li><li>When finished, click on '''Network''' in Windows file manager to confirm that the network share is present.</li><li>Try to create a file on Windows on your Linux Samba machine. Were you able to create a save a file?</li><li>Switch to your VM2 machine and check to see if that file was created in your home directory.</li></ol>
  
 
{{Admon/important |Backup your VMs!|You MUST perform a '''full backup''' of ALL of your VMs whenever you complete your '''OPS335 labs''' or when working on your '''OPS335 assignments'''. You should be using the dump command, and you should use  the Bash shell script that you were adviced to create in order to backup all of your VMs.}}
 
{{Admon/important |Backup your VMs!|You MUST perform a '''full backup''' of ALL of your VMs whenever you complete your '''OPS335 labs''' or when working on your '''OPS335 assignments'''. You should be using the dump command, and you should use  the Bash shell script that you were adviced to create in order to backup all of your VMs.}}
  
'''Record steps, commands, and your observations on this investigation in your OPS335 lab log-book'''
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'''Record steps, commands, and your observations from this INVESTIGATION in your OPS335 lab log-book'''
  
== COMPLETING THE LAB ==
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==COMPLETING THE LAB==
You now have a complete LAMP stack and could host a variety of web-pages that could include dynamically generated content and database access.
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In completing this lab you have gained experience using a service that allows remote access to files stored on a Linux server.  You have also learned how to use several different tools to access those files, both from a Linux and Windows client..
  
 
'''Depending on your professor you will either be asked to submit the lab in class, or online.  Follow the appropriate set of instructions below.'''
 
'''Depending on your professor you will either be asked to submit the lab in class, or online.  Follow the appropriate set of instructions below.'''
  
 
===Online Submission (Peter Callaghan's Classes only)===
 
===Online Submission (Peter Callaghan's Classes only)===
Follow the instructions for lab 5 on moodle.
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Follow the instructions for lab 5 on blackboard.
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 +
===In Class Submission (Murray Saul's Classes only)===
 +
'''Arrange evidence (command output) for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:'''
  
===In Class Submission===
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::<span style="color:green;font-size:1.5em;">&#x2713;</span> Proof of network share of VM2 machine from Windows VM via Windows Explorer application
::<span style="color:green;font-size:1.5em;">&#x2713;</span>Download the labcheck5.bash checking bash shell script by issuing the command:<br><br>'''wget http://matrix.senecac.on.ca/~peter.callaghan/files/OPS335/labcheck5.bash'''<br><br>set execute permission and run the shell script on your '''c7host''' machine.  
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::<span style="color:green;font-size:1.5em;">&#x2713;</span> Firewall settings on your Windows VM to allow Linux Samba network share
 +
::<span style="color:green;font-size:1.5em;">&#x2713;</span> Display contents of '''/etc/samba/smb.conf''' file on VM2 machine
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::<span style="color:green;font-size:1.5em;">&#x2713;</span> Firewall exceptions (both machines) to allow Samba traffic
 +
::<span style="color:green;font-size:1.5em;">&#x2713;</span>Download the labcheck5.bash checking bash shell script by issuing the command:<br><br>'''wget http://matrix.senecac.on.ca/~peter.callaghan/files/OPS335/labcheck5.bash'''<br><br>set execute permission and run the shell script on your '''host''' machine.  
 
::*For '''Peter's classes''', follow his Online Submission instructions in Moodle.
 
::*For '''Peter's classes''', follow his Online Submission instructions in Moodle.
::*For '''Murray's classes''', run command  (piping to the '''more''' command) and show output to instructor.
+
::*For '''Murray's classes''', run the bash script on host and vm2 (piping to the '''more''' command) and show output to instructor.
 
::<span style="color:green;font-size:1.5em;">&#x2713;</span>Completed Lab5 log-book notes.
 
::<span style="color:green;font-size:1.5em;">&#x2713;</span>Completed Lab5 log-book notes.
  
To be completed by an instructor who uses in-class submissions.
+
==EXPLORATION QUESTIONS==
  
==EXPLORATION QUESTIONS==
 
  
# What does the term LAMP stand for? Briefly describe the purpose of each of the following items in LAMP.
+
#What does SMB stand for?
# What is the major difference between a static web document and a dynamic document?
+
#What does CIFS stand for?
# What does the term "server-side programming" mean?
+
#What is the purpose of the '''testparm''' command?
# What is the purpose of creating and using an index.html file?
+
#What does the text inside square brackets in the '''smb.conf''' file mean? (e.g., "[home]").
# What is the purpose of creating and using an index.php file?
+
#Explain the meaning of the line "create mask = 0765" in the smb.conf file?
 +
#What does the '''smbpasswd''' command do?

Revision as of 21:27, 6 March 2019


OBJECTIVE & PREPARATION

According to the samba.org website:

"Samba is the standard Windows interoperability suite of programs for Linux and Unix. Samba is Free Software licensed under the GNU General Public License, the Samba project is a member of the Software Freedom Conservancy."

Although a Samba server can provide many features such as printer sharing and backups, this lab's primary focus is to set up a Samba server on a Linux server in order to allow MS Windows users to share common files from the Linux's Samba server.

This lab will first install, setup, and enable a Samba server. Then users will access files on the Linux Samba server from Linux and Windows client machines (both graphically and command line).

Online Resources

INVESTIGATION 1: INSTALLING & CONFIGURING A SAMBA SERVER

In this investigation, we will set up a Samba server on our VM2 machine. We will first install, configure and enable the samba server on our virtual machine, and then we will quickly test to see if the Samba server works.


Perform the following steps:

  1. Make certain that both your VM1 and VM2 machines are running.
  2. Switch to your VM2 machine as the root user.
  3. Issue the following Linux command to install Samba server utlity:
    yum install samba samba-client
  4. Copy the file /etc/samba/smb.conf to another filename by issuing the following command:
    cp /etc/samba/smb.conf /etc/samba/smb.conf.original
  5. Clear the contents of the configuration file by running cat /dev/null > /etc/samba/smb.conf
  6. Edit /etc/samba/smb.conf so that the file that contains the following lines:
[global]
workgroup = WORKGROUP 
server string = "put your real name here without the quotes"
encrypt passwords = yes
security = user
passdb backend = tdbsam

[home]
comment = "put your real name here without the quotes"
path = /home/<yourSenecaID>
public = no
writable = yes
printable = no
create mask = 0765

[homes]
comment = automatic home share
public = no
writable = yes
printable = no
create mask = 0765
browseable = no
  1. Append (add) the following parameter to the bottom of the [global] section that will limit access to the share so that only machines in your virtual network will be able to access it:
hosts allow = 192.168.x. 127.0.0.1
  1. Append (add) the following parameter to the [home] section so that only your user account can access that share:
valid users = <yourSenecaID>
  1. Create a Samba account and password for yourSenecaID by issuing the following command:
    smbpasswd -a <yourSenecaID>
Idea.png
Changing Existing Samba Account Passwords
If you need to change a user's existing Samba account password, you can issue the following command as root: smbpasswd username.
  1. Confirm the user you created has been added using the following command:
    pdbedit -L -v
  2. Test and review your configuration with the command:
    testparm
  3. Use the systemctl command to start the smb.service and enable the service to run on boot-up
  4. Since we set SELinux to enforcing, we will need to tell it to allow samba access to home directories: setsebool -P samba_enable_home_dirs 1
  5. Use the ss -nautp command to see with port Samba is running on.
  6. Use the information in the previous step to modify the firewall on VM2 machine to allow samba traffic.
  7. Test to see that you can connect to your Samba server (locally) by issuing the following command:
    smbclient -U <yourSenecaID> -L 127.0.0.1
  8. When prompted, enter your Samba account password.
  9. The output from that issued command show appear similar to example displayed below:
Sharename       Type       Comment
---------       ----       -------
home             Disk      Your Name
IPC$             IPC       IPC Service ("Your Name")
Domain=[WORKGROUP] OS=[Windows 6.1] Server=[Samba 4.2.3]

Server                Comment
------                -------

WorkGroup             Master
---------             ------

  1. To access the Samba client shell on your local Samba share, issue the following command:
    smbclient '\\127.0.0.1\home' -U <yourSenecaID>
  2. Enter your Samba account password.
  3. Issue the help command to note common commands (dir, cd, ls, put, get). Note how similar they are to sftp commands.
  4. Enter exit to terminal your local Samba session.

You can use smbclient to access, browse and share files within other Linux and Windows servers using a variety of tools which will be demonstrated in Investigations 2 and 3.

Record steps, commands, and your observations in INVESTIGATION 1 in your OPS335 lab log-book

INVESTIGATION 2: CONNECTING TO A LINUX SMB SERVER FROM A LINUX CLIENT

In this investigation you will explore some of the different ways to access a shared directory from a Linux client machine (VM1).

Installing and Using smbclient

Perform the following steps on your VM1

  1. Install the samba-client and cifs-utils packages.
  2. Use the "smbclient" command in a terminal window.
     smbclient '\\vm2\home' -U <yourSenecaID>
  3. After entering your password you should get a prompt similar to:
     smb: \>
  4. Enter the ls command to see a list of the files in your home directory:
     smb: \> ls
  5. Once you have access to the directory use the get and put commands (similar to ftp) to move files.
  6. When you are finished close the connection.
  7. Try again using [homes] share instead
 smbclient '\\vm2\homes' -U <yourSenecaID>

Did it work even though you didn't specify path=/home/<yourSenecaID> under [homes]?

Note that this tool only gave temporary access with a limited set of commands.

Using 'mount -t cifs'

Instead of always having to use the smbclient command to connect to your network share, you can have the share automatically mounted upon your file server boot-up.


Perform the following steps on your VM1

  1. Issue the following commands to create a mount-point and to mount your home directory from your vm2 machine:
     mkdir /tmp/vm2-home
     mount -t cifs //vm2/home /tmp/vm2-home -o username=<yourSenecaID>
     ls /tmp/vm2-home
  2. Create a file in that directory, then switch to vm2 to confirm that it was created.
  3. Use umount on vm1 to unmount that directory.


Note that this tool would leave the directory mounted until the machine rebooted or it was manually unmounted. It would also allow other users access to the directory, as it effectively became part of the local filesystem. It could even be added to fstab to be mounted on boot (though this would require another configuration file we don't cover).

Using Nautilus to browse Samba shares

Instead of accessing your file share via CLI, you can also connect, navigate and access your file share via a graphical application such as a file browser or a web-browser.

Perform the following steps on your HOST machine:

  1. Install the samba-client and cifs-utils packages.
  2. Use the "Places" menu from the desktop and open 'Browse Network'.
  3. From the menu in the side-bar of the files tool, choose 'Other Locations'.
  4. In the bar titled 'Connect to Server' enter smb://vm2/home as the location, and enter your samba password in the prompt
    (Where vm2 is the name of the server, and home is the name of the directory it is sharing).
  5. After you have checked that you can access your files, unmount the share by right-clicking its icon in the side-bar and clicking 'Unmount'.


You can also use a web browser with support for the SMB protocol such as Konqueror (Note that firefox does not have such support)


  1. If Konqueror is not installed then install it with the command:
     yum install kdebase
  2. Start Konqueror, the web/file browser, and in the address bar enter the following:
    smb://vm2/home
  3. Enter your username and password when prompted.
  4. Double click on a file you have some text in.
  5. Open it with gedit, make some changes, and save it.
  6. When prompted, choose to upload the file.
  7. Close Konqueror.
  8. cat the file on your VM2 to ensure the changes were properly uploaded.


Record steps, commands, and your observations from this INVESTIGATION in your OPS335 lab log-book

INVESTIGATION 3: CONNECTING TO A SAMBA SERVER FROM A WINDOWS CLIENT

This investigation will configure your VM2 machine to act as a Samba File server to allow Windows OS Users access to the Linux Samba server files.

Accessing Files on a Linux Samba Server via Windows Explorer

With some additional "tweaking" to your Linux Samba server configuration file, you should be able to access files on that file from a Windows machine on the same network. You will be creating a Samba share for your home directory of your regular user account.

Perform the following tasks:

  1. Make certain that your VM2 machine is running, is still allowing samba traffic through the firewall, and is still running the samba service.
  2. If you are using a drive in the removable bay, power up a Windows system in the lab and login. If you are using a USB SSD drive, use the Windows machine you are already on.
  3. Add the prerouting and forwarding rules to your host's iptables necessary to redirect samba traffic from outside your network to your VM 2.
  4. Modify the hosts allow setting on your vm2 to also accept connections from the windows machine you are using.
  5. Open the Windows File Explorer application.
  6. At the top of the application, enter the following:
    \\IPADDR_OF_HOST_MACHINE\home
You will be prompted (once only) for the Samba user-name and password for your VM2 machine).
You can create a mapped network drive (z:) for your Linux Samba server network share).
  1. You will be prompted to enter your samba username and password (one time only). Refer to diagram on right.

    NOTE: It may take approximately 30 seconds to display the file contents.

  2. Were you successful? You should have received an error stating the your credentials are incorrect. You will notice that it adds SENEDS to the beginning of your user name, as the Seneca machine is pre-configured to be part of that workgroup.
  3. Change the workgroup parameter in smb.conf on VM2 to match the seneca domain SENEDS, and try to connect again.
  4. Were you successful? If not, try to troubleshoot the problem first, then ask your lab assistant or instructor for assistance.
  5. Close the Windows File Explorer application window.
  6. Click on the START menu, and click on This PC.
  7. Click on the Map Network Drive button, and create a mapped network drive (called it drive Z:) which is a Samba share of your VM2 machine for the home directory.
  8. When finished, click on Network in Windows file manager to confirm that the network share is present.
  9. Try to create a file on Windows on your Linux Samba machine. Were you able to create a save a file?
  10. Switch to your VM2 machine and check to see if that file was created in your home directory.
Important.png
Backup your VMs!
You MUST perform a full backup of ALL of your VMs whenever you complete your OPS335 labs or when working on your OPS335 assignments. You should be using the dump command, and you should use the Bash shell script that you were adviced to create in order to backup all of your VMs.

Record steps, commands, and your observations from this INVESTIGATION in your OPS335 lab log-book

COMPLETING THE LAB

In completing this lab you have gained experience using a service that allows remote access to files stored on a Linux server. You have also learned how to use several different tools to access those files, both from a Linux and Windows client..

Depending on your professor you will either be asked to submit the lab in class, or online. Follow the appropriate set of instructions below.

Online Submission (Peter Callaghan's Classes only)

Follow the instructions for lab 5 on blackboard.

In Class Submission (Murray Saul's Classes only)

Arrange evidence (command output) for each of these items on your screen, then ask your instructor to review them and sign off on the lab's completion:

Proof of network share of VM2 machine from Windows VM via Windows Explorer application
Firewall settings on your Windows VM to allow Linux Samba network share
Display contents of /etc/samba/smb.conf file on VM2 machine
Firewall exceptions (both machines) to allow Samba traffic
Download the labcheck5.bash checking bash shell script by issuing the command:

wget http://matrix.senecac.on.ca/~peter.callaghan/files/OPS335/labcheck5.bash

set execute permission and run the shell script on your host machine.
  • For Peter's classes, follow his Online Submission instructions in Moodle.
  • For Murray's classes, run the bash script on host and vm2 (piping to the more command) and show output to instructor.
Completed Lab5 log-book notes.

EXPLORATION QUESTIONS

  1. What does SMB stand for?
  2. What does CIFS stand for?
  3. What is the purpose of the testparm command?
  4. What does the text inside square brackets in the smb.conf file mean? (e.g., "[home]").
  5. Explain the meaning of the line "create mask = 0765" in the smb.conf file?
  6. What does the smbpasswd command do?