This script automate the process to create random username and password and required role with privilages for Packer to work with Proxmox Host.

proxmox-packer-user-creator.sh

#!/bin/bash

# Function to generate a strong password
generate_password() {
  cat /dev/urandom | tr -dc 'a-zA-Z0-9!@#$%^&*()-_+=~' | fold -w 16 | head -n 1
}

# Function to generate a random username
generate_username() {
  cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 8 | head -n 1
}

# Step 1: Detect Proxmox Hostname or ask the user if detection fails
HOSTNAME=$(hostname -f)
if [ -z "$HOSTNAME" ]; then
  read -p "Unable to detect Proxmox hostname. Please enter it: " HOSTNAME
fi

# Step 2: Ask the user for the username and password, generate them if not provided
read -p "Enter the username for the new user (Press Enter to generate a random username): " USERNAME
if [ -z "$USERNAME" ]; then
  USERNAME=$(generate_username)
fi

read -sp "Enter the password for the new user (Press Enter to generate a random password): " PASSWORD
echo
if [ -z "$PASSWORD" ]; then
  PASSWORD=$(generate_password)
fi

# Step 3: Execute the commands to add the user with the specified privileges
pveum useradd $USERNAME@pve
pveum passwd $USERNAME@pve <<EOF
$PASSWORD
EOF

# Adding role with the necessary privileges
PRIVILEGES="VM.Config.Disk,VM.Config.CPU,VM.Config.Memory,Datastore.AllocateSpace,Sys.Modify,VM.Config.Options,VM.Allocate,VM.Audit,VM.Console,VM.Config.CDROM,VM.Config.Network,VM.PowerMgmt,VM.Config.HWType,VM.Monitor"
pveum roleadd Packer -privs "$PRIVILEGES"

# Assigning the role to the user
pveum aclmod / -user $USERNAME@pve -role Packer

# Step 4: Display all necessary information to the script operator
echo -e "User addition successful!\n"
echo "Proxmox Hostname: $HOSTNAME"
echo "New User Username: $USERNAME"
echo "New User Password: $PASSWORD"
echo "New User Role: Packer"
echo -e "Privileges assigned to the role:\n$PRIVILEGES"