Hello World,
In some previous posts, we have demonstrated how to deploy Ubuntu 18.04 through PXE technology. Ubuntu 20.04 has been released for some time now, it’s time to provide some updates about the PXE deployment. Ubuntu 20.04 has introduced some changes that might impact the way a deployment through the network can be performed. If you look for information on how to deploy Ubuntu 18.04 through PXE, please read the following posts
- Ubuntu – Ultimate PXE Server Setup – BIOS & UEFI Support
- Ubuntu – Setup PXE Server using pxelinux files only (Bios & UEFI Support)
- Ubuntu – Ubuntu PXE Server using only Grub files (BIOS & UEFI Support)
- Ubuntu 18.04 – How to install Ubuntu 18.04 Server through PXE – Part I
- Ubuntu 18.04 – How to install Ubuntu Desktop through PXE – Part II
- Ubuntu 18.04 – How to install UEFI Ubuntu client through PXE infrastructure – Part III
So, let’s focus on Ubuntu 20.04 and see how the process has changed (or not !!)
Overview
This guide will describe the necessary steps needed in order to deploy Ubuntu 20.04 Desktop through the network using PXE technology. To deploy operating systems through PXE technology, there are some server roles and services that needs to be present on the network. PXE deployments relies on DHCP,DNS, TFTP, File and Web Services. In this post, we will prepare the infrastructure needed to have PXE capabilities. This setup guide will allow the deployment of Ubuntu 20.04 Desktop Edition to UEFI or Bios based systems.
Let’s go !
Step by Step Guide
Assumptions
The following assumptions have been made in order to have this scenario working
- You have internet connection in order to download additional necessary packages
- You have Ubuntu 20.04.1 Desktop ISO or installation files
- The PXE Server will be hosted on Ubuntu 20.04 Desktop
- Our virtual plaftorm is based on Hyper-V Server
- VM Generation 2 will be used in order to have UEFI and SecureBoot option is Enabled (detailed instruction can be found here)
Step 0 – Installing Ubuntu 20.04 Desktop
We will need to have a “PXE Server” deployed on the network. In our scenario, an Ubuntu 20.04 Desktop system will be used. This machine will host the necessary services needed to deploy operating system through network. Obviously, you could have used Ubuntu Server Edition as the steps and processes are quite similar. Be sure that Ubuntu 20.04 Desktop has the latest updates installed.
Step 1 – Download necessary packages
In this post, we assume that the Ubuntu Desktop 20.04 will be hosting all the necessary services needed to implement a proper PXE Infrastructure. To setup a PXE infra, we need to install the following packages
- dnsmasq (providing DHCP,DNS and TFTP services),
- apache web for storage purposes and
- NFS packages if you are planning to deploy Ubuntu Desktop through your PXE infrastructure.
Step 1.1 – Install apache web server
To install the apache package, you will issue the following command
sudo apt-get install apache2
Step 1.2 – Install NFS packages
NFS packages will provide file services capabilities. To install the nfs packages, execute the following commands
sudo apt-get install nfs-kernel-server
Step 1.3 – Install dnsmasq packages
To install the dnsmasq package, you will issue the following command
sudo apt-get install dnsmasq
During the installation, you will see some errors and warnings. At this stage, this is an expected behavior. Additional configuration will be needed at later stage
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Step 1.4 –Download pxelinux Packages
We will first download the PXELinux package from the web site creator
mkdir ~/Downloads/syslinux cd ~/Downloads/syslinux wget https://mirrors.edge.kernel.org/pub/linux/utils/boot/syslinux/syslinux-6.03.zip unzip syslinux-6.03.zip
Step 1.5 –Download “UEFI” Packages
The commands below basically will download the necessary signed bootloader files and grub files needed by PXE server and extract the contents on their dedicated folders (shim and grub). These files are needed to pxeboot uefi clients…..
apt-get download shim.signed dpkg -x <%name of deb package%> shim apt-get download grub-efi-amd-signed dpkg -x <%name of deb package%> grub
Step 2 – Setup Static IP Address
Usually, Ubuntu installation are using dynamic ip addresses (DHCP). We will move from the dynamic configuration to a static configuration. To perform such operation, you will click on the network icon on the right side of the top bar > expand the wired connected and select wired settings
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In the right pane, click the gear to open the properties pages
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Go to the IPv4 tab
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Change from Automatic to Dynamic and set the necessary ip address information. Press the Apply button and you are back to the network settings page
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To effectively apply the changes, you have to disable and re-enable the network by using the slider button (or you can reboot the computer)
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To check that the correct ip address has been set, you can open the terminal console and issue the following command ip addr. In the screenshot, we can see that the ip address is set accordingly. take also a note of the name of the interface (in the screenshot, it’s eth0) as this information will be needed at a later stage
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Step 3 – Create the TFTP Folder Structure
We will create a folder called tftp at root of the filesystem (/tftp). Within this folder, the following structure will be create
tftp |-bios |-boot |-grub
To create this structure, you will need to execute the following commands in your Terminal Console
sudo mkdir /tftp sudo mkdir /tftp/bios sudo mkdir /tftp/boot sudo mkdir /tftp/grub
Step 4 – Create the web Folder Structure
Because you are using the Apache Web server, we will be copying all sources files under /var/www/html directory. We will copy the iso files contents of Ubuntu 20.04 Desktop and Ubuntu Server under this location.
Our structure will look like the following representation. Obviously, you can create your own structure
var |-www |-html |-server |-ubuntu-20.04 |-ubuntu-18.04 |- ... |-desktop |-ubuntu-20.04 |-ubuntu-18.04 |- ...
To create the following folder structure, you can use the following commands in a Terminal Console
sudo mkdir /var/www/html/desktop/ sudo mkdir /var/www/html/desktop/ubuntu-20.04 sudo mkdir /var/www/html/desktop/ubuntu-18.04 sudo mkdir /var/www/html/server
Step 5 – Populate the web folder structure
So, mount your iso file into your Ubuntu PXE machine. To mount it, issue the following command
sudo mount /dev/sr0 /media
Copy the files from the iso image into the correct directory. You can use the following syntax to perform the operation
sudo cp -rf <%Your Path To Install Files%>/* /var/www/html/desktop/focal example : sudo cp -rf /media/* /var/www/html/desktop/u2004
When the copy is finished, unmount the iso/DVD image from your machine by issuing the following command
sudo umount /media
You can check that your files have been copied accordingly by browsing to /var/www/html/desktop/xxxx.
Step 6 – Configuring your NFS Server Settings
Since our folder structure is ready, we can start configuring the different services that are used by the PXE server. To ensure that our directory structure is accessible through the network and through the nfs protocol, we will need to edit the following file by issuing the following command
sudo nano /etc/exports
Insert at the bottom of the file, the path where you have stored your installation files, which subnet can access it and which kind of right you want to grant. In our scenario, we want to grant access to the following directory /var/www/html/desktop through the network subnet 192.168.1.0/24 and we are granting read only access (ro). So, at the end of the file, we would add the following line
/var/www/html/desktop 192.168.1.0/24(ro)
When this has been done, it’s time to restart the nfs service. To do that, you simply execute the following command
sudo systemctl restart nfs-kernel-server
Step 7 – Configuring the dnsmasq service
Almost there ! Now, we need to configure the dnsmasq service which will provide the glue between the different services. dnsmasq configuration file will be used to provide the necessary information to the pxe client when it boots. This file will dictate where to look for pxe bootloader based on the client architecture (uefi or bios). So, let’s edit the /etc/dnsmasq.conf file and at the bottom add the following information
To edit the configuration file, issue the following command
sudo nano /etc/dnsmasq.conf
Copy and update the following information at the bottom of the file
Note : You will need to modify it accordingly to reflect your own infrastructure
#Interface information #--use ip addr to see the name of the interface on your system interface=eth0,lo bind-interfaces domain=c-nergy.local #-------------------------- #DHCP Settings #-------------------------- #-- Set dhcp scope dhcp-range=192.168.1.160,192.168.1.200,255.255.255.0,2h #-- Set gateway option dhcp-option=3,192.168.1.1 #-- Set DNS server option dhcp-option=6,192.168.1.1 #-- dns Forwarder info server=8.8.8.8 #----------------------# # Specify TFTP Options # #----------------------# #--location of the pxeboot file dhcp-boot=/bios/pxelinux.0,pxeserver,192.168.1.150 #--enable tftp service enable-tftp #-- Root folder for tftp tftp-root=/tftp #--Detect architecture and send the correct bootloader file dhcp-match=set:efi-x86_64,option:client-arch,7 dhcp-boot=tag:efi-x86_64,grub/bootx64.efi
To have the change applied to your system, you will need to restart the dnsmasq service. To perform such task, you will execute the following command
sudo systemctl restart dnsmasq
Then, you should check that the dnsmasq is started correctly and that no errors are reported by issuing the command
sudo systemctl status dnsmasq
Step 8 – Populate TFTP Folder
Now, we need to populate the TFTP folder structure.
Step 7.1 – Populate bios folder
We have created the folder /tftp/bios in a previous step. This folder will hold the needed pxelinux files that we will be using to boot from network
sudo cp <%your download location%>/bios/com32/elflink/ldlinux/ldlinux.c32 /tftp/bios sudo cp <%your download location%>/bios/com32/libutil/libutil.c32 /tftp/bios sudo cp <%your download location%>/bios/com32/menu/menu.c32 /tftp/bios sudo cp <%your download location%>/bios/com32/menu/vesamenu.c32 /tftp/bios sudo cp <%your download location%>/bios/core/pxelinux.0 /tftp/bios sudo cp <%your download location%>/bios/core/lpxelinux.0 /tftp/bios
Step 7.2 – Populate grub folder
We will do the same for the grub folder. The grub folder contains files that are needed for UEFI computers. We will need to obtain the correct version of grub files (the ones that are signed).
When this is done, we can simply copy the needed file into the tftp boot folder. So, execute the following commands. Change the path accordingly based on your settings…
sudo cp ~/Downloads/grub/usr/lib/grub/x86_64-efi-signed/grubnetx64.efi.signed /tftp/grubx64.efi sudo cp ~/Downloads/shim/usr/lib/shim/shimx64.efi.signed /tftp/grub/bootx64.efi
Finally, we will copy two additional files from the source iso image. They will server as base for the next step. So, execute the following commands
sudo cp /var/www/html/desktop/u2004/boot/grub/grub.cfg /tftp/grub/ sudo cp /var/www/html/desktop/u2004/boot/grub/font.pf2 /tftp/grub/
Step 7.3 – Populate boot folder
In this step, we need to place the correct bootloader in order for the installation process to start accordingly. We will copy the necessary files from the /var/www/html location. Issue the following commands to copy the necessary files to the correct location
Note : Ensure that the folder /tftp/boot/casper has been created and exists….
sudo cp /var/www/html/desktop/u2004/casper/vmlinuz /tftp/boot/casper sudo cp /var/www/html/desktop/u2004/casper/initrd /tftp/boot/casper
Step 7.4 – Create symbolic link to boot folder
You will also need to create a symbolic link to the /tftp/boot folder. You will need to issue the following command
sudo ln -s /tftp/boot /tftp/bios/boot
Step 9 – Creating/Updating pxelinux.cfg & grub.cfg file
These are the most important files of the configuration. These files tells the target machine where to connect and where the file source files needed to perform the network installation. So, let’s create them…
Step 9.1 – create you pxelinux configuration file
We will also need to create the folder called pxelinux.cfg under the /tftp/bios folder.
sudo mkdir /tftp/bios/pxelinux.cfg
Inside this folder, we will create an empty file called default. This file control the pxelinux behavior. We will populate it with the following code
DEFAULT menu.c32 MENU TITLE ULTIMATE PXE SERVER - By Griffon - Ver 2.0 PROMPT 0 TIMEOUT 0 MENU COLOR TABMSG 37;40 #ffffffff #00000000 MENU COLOR TITLE 37;40 #ffffffff #00000000 MENU COLOR SEL 7 #ffffffff #00000000 MENU COLOR UNSEL 37;40 #ffffffff #00000000 MENU COLOR BORDER 37;40 #ffffffff #00000000 LABEL Ubuntu Desktop 20.04 kernel /boot/vmlinuz append nfsroot=192.168.1.150:/var/www/html/desktop/u2004 netboot=nfs ip=dhcp boot=casper initrd=/boot/initrd systemd.mask=tmp.mount --
Save it
You are ready to move to the next section
Step 9.2 – create you grub configuration file
We are almost done ! Now, we need to create also a grub boot menu and get the proper option available and working. The grub boot loader reads information from the grub.cfg file. If you have followed this step by step guide, the content of the grub.cfg file should look like this
if loadfont /grub/font.pf2 ; then set gfxmode=auto insmod efi_gop insmod efi_uga insmod gfxterm terminal_output gfxterm fi set menu_color_normal=white/black set menu_color_highlight=black/light-gray set timeout=5 menuentry "Ubuntu Desktop 20.04" { set gfxpayload=keep linux /boot/casper/vmlinuz ip=dhcp nfsroot=192.168.1.150:/var/www/html/desktop/u2004/ netboot=nfs ip=dhcp boot=casper systemd.mask=tmp.mount -- initrd /boot/casper/initrd }
Save it
Step 10 – Testing your implementation
At this stage, we have to validate our work. If everything is working as expected, you will be able to boot a BIOS based computer from the network and you would see the following PXE Menu.
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If you start the process from a UEFI based computer, you will see the following menu
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Selecting the menu option, you will see the boot process starting and at the end of the process, you should be see presented with the live version of the Ubuntu 20.04 Desktop Edition. From there you can perform your manual installation.
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Using some “answer file”; it’s possible to automate the installation of your Ubuntu machine. The automation process will not be explained in this post as the post is becoming really long. Possibly in a future post, we might want to describe and demonstrate the process…..
Final Notes
This is it for this post ! At the beginning of the post, we said that Ubuntu 20.04 introduced some changes and that these changes could impact our ability to perform pxe installation. As we have been specifically discussing the desktop version, we can see that the process is quite similar to the methods and techniques we used with Ubuntu 18.04. The change introduced in Ubuntu 20.04 are more related to the deployment of the server edition where the netboot image is being deprecated. Moreover, the new installation wizard of the Server edition also introduces changes in the way the installation process would occur through the network…
We might publish a post about Ubuntu 20.04 Server Edition and how to work with the new wizard (called Subiquity). We will be able to test and see if deployment through the network is still possible and easy enough to implement
Till next time
See ya