View source for Linux: Golden Image Preparation and Production Deployment

=Introduction=
This article outlines the recommended process for image preparation and production deployment of a custom target O/S image onto IOT-GATE-iMX8 and IOT-GATE-iMX8PLUS devices. 
<br>The suggested flow utilizes the Compulab '''cl-deploy''' and '''cl-auto''' utilities and involves the following steps:</br>
# Creating the desired "golden" image 
# Cloning the image to create production deployment media
# Using the production deployment media for automated unattended installation on any IOT-GATE-iMX8 or IOT-GATE-iMX8PLUS unit

= Creating the Desired "Golden" Image =
This guide assumes that the "source" unit is already running the latest CompuLab Debian package.

=== Apply the Necessary Custom Modifications (optional) ===
Make the required modifications to the root file system, for example:
* Copy the required files
* Install additional packages
* Create the required users
* Update the root user password
* Clean up the history and logs

=== Configure the Automatic Installation Script Behavior ===

The '''cl-auto''' auto-installer utility supports custom exit functions. This allows the user to define device behavior once deployment is finished.

Function names:
* external_okay_exit -- a non-error exit
* external_error_exit -- an error exit

File to place these functions: ''/usr/share/cl-deploy/cl-auto.notifier''

'''Example''':<br>
The following ''cl-auto.notifier'' code sets the device to power-off after a successful installation.
<pre>
cat > /usr/share/cl-deploy/cl-auto.notifier << EOF
# cl-auto.notifier

external_okay_exit() {
# Select Off/Reboot #
dialog_msg="Turn off the device in \${good_timeout} seconds ..."

dialog --yes-label "Turn Off" --no-label "Reboot" --timeout \${good_timeout} --title "cl-deploy: status [ okay ]" --yesno "\${dialog_msg}" 10 60 2>/dev/null
if [[ \$? -eq 1 ]]; then
exit 0
fi

# Turn off the device #
echo 1 > /proc/sys/kernel/sysrq
sync;sync;sync
for cmd in s u o;do echo \${cmd} > /proc/sysrq-trigger ; done
sleep 10
}
EOF
</pre>

= Create Production Deployment Media =
* Use any commercially available USB flash drive sufficient to contain your image. Minimizing the flash drive size will reduce the time of deployment.
{{Important|USB drive size MUST not exceed eMMC size of the target unit</br>Make sure that only one USB flash drive is inserted}}
* Insert the USB flash drive into one of the USB ports of the "source" unit.
* Execute '''cl-deploy''' to copy the contents of the internal storage (eMMC) to the USB flash drive:
<pre>
# cl-deploy
</pre>
* Press the space bar to start the copy process.
* The following message will be displayed when the process is complete:
<pre>
┌──────────────────────────────────────────────────────────────────────────────┐
│ Boot media has been deployed on /dev/sda                                     │
│                                                                              │
│ Would you like to reboot the device now?                                     │
│                                                                              │
│                                                                              │
│                                                                              │
├──────────────────────────────────────────────────────────────────────────────┤
│                         < Yes >             < No  >                          │
└──────────────────────────────────────────────────────────────────────────────┘
</pre>
* Reboot the device with the USB flash drive
* Login with the root user
* Enable the automatic installation:
<pre>
# cl-auto -c
# cl-auto -A
</pre>
* Power off the device
<pre>
# poweroff
</pre>
* Remove the USB flash drive. Now it contains the auto-deployable "golden" image.

= Production Deployment =

* Insert the USB flash drive into one of the USB ports of the target device.
{{Important|Make sure that only one USB flash drive is inserted}}
* Power on the target device.
* The following message will be displayed before the installation begins:
<pre>
         +--------cl-deploy will get started in 5 seconds-----------+
         | Configuration file /etc/cl-auto.conf parameters:         |
         | --------------------------------------------------       |
         | DST=/dev/mmcblk2                                         |
         | QUIET=Yes                                                |
         | --------------------------------------------------       |
         | Press any key for terminating ...                        |
         |                                                          |
         |                                                          |
         |                                                          |
         |                                                          |
         |                                                          |
         +----------------------------------------------------------+
         |                 <Stop Auto Installer>                    |
         +----------------------------------------------------------+
</pre>
* If not interrupted, the installation will begin automatically.
* Wait for the success message:
<pre>
         #####  #     #  #####   #####  #######  #####   #####
        #     # #     # #     # #     # #       #     # #     #
        #       #     # #       #       #       #       #
         #####  #     # #       #       #####    #####   #####
              # #     # #       #       #             #       #
        #     # #     # #     # #     # #       #     # #     #
         #####   #####   #####   #####  #######  #####   #####
</pre>
* Use the space bar and the arrow keys to select power off or reboot:
<pre>
         +---------------cl-deploy: status [ okay ]-----------------+
         |                                                          |
         |                                                          |
         +----------------------------------------------------------+
         |               <Turn Off>        < Reboot >               |
         +----------------------------------------------------------+
</pre>

[[Category:Linux]]
[[Category:Debian]]