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This guide walks through creating an OpenStack Application Credential, setting up a Python environment, installing the snapshot script, and scheduling it to run automatically.

OpenStack VM Snapshot Automation Setup Guide

1. Create an Application Credential

  1. Log in to the Skyline panel for Rackspace OpenStack Flex as shown here
  2. Create your Application Credential with 'creator' role as seen here

  3. After creation, a .json file will be automatically downloaded — save this file securely.

  4. This file contains your Application Credential ID and Secret, which are required for authentication.

2. Create the Virtual Machine (Example: Ubuntu 24.04)

In this example we'll have our snapshot automation script running on a VM so that we don't need to worry about leaving a workstation or something running.

Launch a new VM running Ubuntu 24.04 LTS through the OpenStack Dashboard or CLI. You can see our guide on this here

Once your VM is active, connect via SSH.

NOTE: Your VM does not need a Floating IP to perform the snapshot functions, but if it doesn't have a Floating IP you'll need to SSH into it from another VM on the same private network.

3. Prepare the Python Environment

Run the following commands to install dependencies and create a virtual environment:

python3 --version
sudo apt install python3-pip -y
sudo apt install python3-openstacksdk -y
sudo apt install python3.12-venv -y

sudo python3 -m venv ~/venv/openstack
source ~/venv/openstack/bin/activate

pip install --upgrade pip
pip install openstacksdk

4. Install the Snapshot Script

Download the snapshot management script:

wget https://raw.githubusercontent.com/brianabshier/python_scripts/main/snapshot_vms.py -O ~/snapshot_vms.py

Update the script to include your Application Credential values from the downloaded JSON file. In my example I'm using the DFW region for the endpoint - but change it to the region you need:

# --- CONFIGURATION ---
AUTH_URL = "$https://keystone.api.dfw3.rackspacecloud.com/v3"
APP_CRED_ID = "$APPLICATION_CRED_ID"
APP_CRED_SECRET = "$APPLICATION_CRED_SECRET"

Make the script executable:

chmod +x ~/snapshot_vms.py

5. Excluding VMs from Snapshot

Inside the .snapshot_data directory, you can create the following files to exclude specific instances:

  • exclude_ids.txt — one instance ID per line
  • exclude_names.txt — one instance name per line

Example:

mkdir -p ~/.snapshot_data
echo "vm-name-to-skip" >> ~/.snapshot_data/exclude_names.txt

6. Schedule Automatic Snapshots (Cron)

To run the script daily at 2:30 AM UTC, edit your crontab:

crontab -e

Add the following line:

30 2 * * * /usr/bin/python3 /home/ubuntu/snapshot_vms.py >> /home/ubuntu/.snapshot_data/snapshot.log 2>&1

Note: If your server uses UTC, the job will run at 2:30 AM UTC. Adjust the schedule if needed.

7. Log and Output

All logs will be written to:

~/.snapshot_data/snapshot.log

You can monitor output with:

tail -f ~/.snapshot_data/snapshot.log

Summary

  • Created OpenStack Application Credential (creator role)
  • Set up Python virtual environment
  • Installed snapshot_vms.py
  • Configured exclusions for VMs
  • Scheduled automated daily execution