Manually configuring MacOS/OSX for Barracuda RMM

These instructions assume an intermediate familiarity with MacOs, terminal emulators, and bash/shell commands.
In Barracuda RMM, navigate to Site Management > Sites > The name of the site this device belongs to > Credentials.
Ensure that there are credentials in place for SNMP, SSH, and optionally VNC.
Ensure you know what the passwords are for the configured SSH and VNC credential sets that are configured there.
Take note of the SNMP community string(s) you have configured.
Log in to the Mac you wish to configure with an Administrator-level account. Make sure you know the password for the account you are logged in with, as you will be prompted for it.

If the file /etc/snmp/snmpd.conf exists, back it up before proceeding.
Open a terminal window.
Run the following commands from the terminal, replacing them with the community string you have configured for the site:

sudo launchctl unload -w /System/Library/LaunchDaemons/org.net-snmp.snmpd.plist sudo printf "rocommunity \nsysobjectid 1.3.6.1.4.1.8072.3.2.16\n" > /etc/snmp/snmpd.conf sudo launchctl load -w /System/Library/LaunchDaemons/org.net-snmp.snmpd.plist

Choose Apple menu > System Preferences, then click Users & Groups.
Click the lock icon to unlock it, then enter the username and password of an existing Administrator.
Click Add below the list of users.
Click the New Account pop-up menu, then choose Administrator.
Enter a Full Name for the new user. (This can be anything.)
Change the Account Name to be the SSH username you have configured in Barracuda RMM.
Set the password to the SSH password you have configured in Barracuda RMM.
Select Allow user to administer this computer.
Click Create User.

Open a terminal window.
Enter the following command: sudo visudo
Ensure that the following line is listed in the sudoers file you just opened, with replaced by the SSH username you have configured in Barracuda RMM: ALL=(ALL) NOPASSWD: ALL
Save and exit visudo with the command: :wq
Optionally, run the following commands from the terminal to hide the service account. As usual, replace with the username you have configured in Barracuda RMM:
sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add mei sudo mv /Users/ / /var// sudo dscl . -create /Users/ NFSHomeDirectory /var/

If the Apple Remote Agent (ARDAgent) service is running (eg. with the Activity Monitor or the ps command), stop it.
Open a terminal window.
Run the following command, replacing with a valid username (either the current user or the SSH username Barracuda RMM is using), and with the VNC password configured in Barracuda RMM:
sudo /System/Library/CoreServices/RemoteManagement/ARDAgent.app/Contents/Resources/kickstart -activate -configure -access -on -privs -all -users -clientopts -setvnclegacy -vnclegacy yes -clientopts -setvncpw -vncpw "" -restart -agent -privs -all

Open a terminal window.
Run the following command to see if the com.apple.access_ssh group already exists or not: sudo dseditgroup com.apple.access_ssh
If it does not already exist, run the following command as well: sudo dseditgroup -o create -q com.apple.access_ssh
Run the following command to add the service account to the SSH group, replacing with the SSH username you have configured in Barracuda RMM:

sudo dseditgroup -o edit -a -t user com.apple.access_ssh
Run the following command to enable remote login: sudo systemsetup -setremotelogin on