Category: Python

VMWare Workstation 15 REST API – Control power state for multiple machines via Python

Or..How to easily power up/suspend your entire K8s cluster at once in VMWare Workstation 15

In VMWare Workstation 15, VMWare introduced the REST API, which allows all sorts of automation.  I was playing around with it, and wrote a quick Python script to fire up (or suspend) a bunch of machines that I listed in an array up top in the initialization section. In this case, I want to control the state of a 4-node Kubernetes cluster, as it was just annoying me to click on the play/suspend 4 times (I have other associated virtual machines as well, which only added to the annoyance.)

Your REST API exe (vmrest.exe) MUST be running if you’re going to try this. If you haven’t set that up yet, stop here and follow these instructions.  You’ll notice that Vmrest.exe normally runs as an interactive user mode application, but I’ve now set up the executable to run as a service on my Windows 10 machine using NSSM, I’ll have a separate blog entry to show how that’s done.

Some notes on the script:

  • Script Variables – ip/host:port (you need the port, as vmrest.exe gives you an ephemeral port number to hit), machine list, and authCode
  • Regarding the authCode.  WITH vmrest.exe running, go to “https://ip_of_vmw:port” to get the REST API explorer page (shown below). Click “authorization” up top, and you’ll get to log in. Use the credentials you used to set up the VMW Rest API via these instructions. 

Screen Shot 2019-12-24 at 3.05.04 PM.png

Then do a “Try it out!” on any GET method that doesn’t require variables and your Auth Code will appear in the Curl section in the “Authorization” header. Grab that code, you’ll use it going forward.

curl.png

Here’s the script, with relatively obvious documentation. Since more than likely your SSL for the vmrest.exe API server will use a self-signed, untrusted certificate, you’re probably going to need to ignore any SSL errors that will occur. That’s what the “InsecureRequestWarning” stuff is all about, we disable the warnings.  My understanding is that the disabled state is reset with every request made, so we need to re-disable it before every REST call.

I’ve posted this code on GitHub HERE.

#!/usr/bin/env python3
import requests
import urllib3
import sys
from urllib3.exceptions import InsecureRequestWarning

'''Variable Initiation'''

ip_addr = 'your-ip-or-hostname:Port' #change ip:port to what VMW REST API is showing
machine_list = ['k8s-master','k8s-worker1','k8s-worker2','k8s-worker3']
authCode = 'yourAuthCode'

'''Section to handle the script arg'''

acceptable_actions = ['on', 'off', 'shutdown', 'suspend', 'pause', 'unpause']

try:

    sys.argv[1]

except NameError:

        action = "on"

else:

    if sys.argv[1] in acceptable_actions:

        action = sys.argv[1]

    else:

        print("ERROR: Action must be: on, off, shutdown, suspend, pause, or unpause")

        exit()


'''Section to get the list of all VM's '''

urllib3.disable_warnings(category=InsecureRequestWarning)

resp = requests.get(url='https://' + ip_addr + '/api/vms', headers={'Accept': 'application/vnd.vmware.vmw.rest-v1+json', 'Authorization': 'Basic ' + authCode}, verify=False)

if resp.status_code != 200:

    #something fell down

    print("Status Code " + resp.status_code + ": Something bad happened")

result_json = resp.json()


'''Go through entire list and if the VM is in the machine_list, if so,
 act! '''

for todo_item in resp.json():

    current_id = todo_item['id']

    current_path = todo_item['path']

    for machine in machine_list:

        if current_path.find(machine) > -1:

        print(machine + ': ' + current_id)

        urllib3.disable_warnings(category=InsecureRequestWarning)

        current_url = 'https://' + ip_addr + '/api/vms/' + current_id + '/power'

        resp = requests.put(current_url, data=action, headers={'Content-Type': 'application/vnd.vmware.vmw.rest-v1+json', 'Accept': 'application/vnd.vmware.vmw.rest-v1+json', 'Authorization': 'Basic ' + authCode}, verify=False)

        print(resp.text)

        '''Better exception handling should be written here of course.
**12/27/19 NOTE!** – I’ve noticed what I believe to be a bug in VMW 15.5 where if you control power state via the REST API, you lose the ability to control the VM via the built-in VMWare console in the app.  The VMs behave fine (assuming everything else is working), but for some reason the VMW app doesn’t attach the console process correctly.  If you want to follow this issue I’ve submitted to the community here.

Use Google Cloud Functions (Python) to modify a GKE cluster

I wanted to create a way to easily “turn on” and “turn off” a GKE cluster, via an HTTP link that I could bookmark and hit, even from my iPhone. With GKE, if you set your node pool size to zero, you’re not incurring any charge since Google doesn’t hit you on the master nodes. So I wanted to easily set the pool size up and down.  Sure, I could issue a “gcloud container” command, or set up Ansible to do it (which I will do since I want to automate more stuff), but I also wanted to get my feet wet with Cloud Functions and GCP API’s.

In Google Cloud Functions, you simply write your functional code in the main file (main.py), AND include the correct dependencies in the requirements.txt file (for Python).  That dependency is represented by the same name of the module you’d use in a “pip install”.  The module for managing GKE is “google-cloud-container“.

Now one of the great things about using Cloud Functions is that authorization for all API’s within your project “just happen”.  You don’t need to figure out OAuth2 or use API keys.  You just need to write the code. If you’re going to use this python code outside of Cloud Functions, you’d need to add some code for that and set an environment to point to your secret json file for the appropriate service account for your project.

Here’s sample code to change your GKE Cluster node pool size.

import google.cloud.container

def startk8s(request):
    client = google.cloud.container.ClusterManagerClient()
    projectID = '<your-project-id>' 
    zone = 'us-east1-d' """ your zone obviously """
    clusterID = '<your-cluster-name>' 
    nodePoolID = 'default-pool' """ or your pool name """
    client.set_node_pool_size(projectID, zone, clusterID, nodePoolID, 3)
    return "200"

You need to set the name of the Function you want triggered:

execute

Notice the import statement- “google.cloud.container”.  Now you can’t exactly “pip install” into a Cloud Function, it’s not your Python instance! That’s where the dependency.txt file comes in.  (There’s a version of that for node.js – package.json, since you can’t npm install either). Here’s the sample dependency.txt file:

# Function dependencies, for example:
# package>=version
google-cloud-container

Note that the package version seems to be optional.  My code works without it.

You can test the cloud function by clicking on the “testing” sub-menu.