You could use the API and some scripting to accomplish this.
Example: If you had a CSV with a column that included serial number, name or JSS ID of the computer and another column that included the "role" you could build a loop that submitted the Extension Attribute for the individual computer object.
One thing to note: Since you are using a drop down menu, you will need to match the drop down options exactly in the second column. If you don't then it will cause an error in the assignment.
#!/bin/bash
# This is your unix line ending formated csv file of serial Numbers
# First Column is labeled serial, Second Column is labeled dropdown_value
INPUT=/Users/demo/Desktop/Extension_Attribute_Example.csv
# Set the file seperator to read the CSV correctly
OLDIFS=$IFS
IFS=,
# JSS URL to PUT based on Serial Number. This could be "id" or "name"
JSSURL="https://jss.yourcompany.com:8443/JSSResource/computers/serialnumber/"
# XML File that you're writing for each computer to upload using the API to make changes
XMLFILE=/tmp/demo_api.xml
# Basic Output in Terminal Window
echo "Running"
# Creates the XML File from above. Currently It's Blank
touch $XMLFILE
# This is where the magic happens. This is a bash loop.
# In English. If the Input file doesn't exists, spit out an error
[ ! -f $INPUT ] && { echo "$INPUT file not found"; exit 99;}
# Read the two column and make them usable as a variable
while read serial drop_downvalue
# Do what I tell you to do
do
# Basic output in the shell window showing your progress
# followed by the creation of the XML file using the variable and storing it in the XMLFILE location from above.
echo "$serial $dropdown_value"
echo "<computer><extension_attributes><extension_attribute><id>17</id><name>Extension Attribute Name</name><type>String</type><value>$dropdown_value</value></extension_attribute></extension_attributes></computer>" > $XMLFILE
# This is the call to the API using cURL. It builds a unique URL for each Serial Number and PUT's the XML File in the request
curl -k -v -u CasperAPI:kcs123z $JSSURL$serial -T $XMLFILE -X PUT
done < $INPUT
# Putting things back where we found them.
IFS=$OLFIFS
Note: The ID number in the XML will be different depending on which extension attribute you use. You can get this ID by going to Computer Management in the JSS, click on Extension Attributes, then click on the EA you are wanting to change. It will be in the URL like this: (I've bolded the ID number in this example)
https://jss.yourcompany.com:8443/computerExtensionAttributes.html?id=34&o=r
Obviously this isn't tested. If you have a test environment, i would recommend honing your script there. Also, start with a small list of 3-5 computers in your CSV file so you can get a feel for what is happening before tacking the full list.
