How to Script the CF API With `CF OAUTH-TOKEN` and Python by@cfweibel

How to Script the CF API With `CF OAUTH-TOKEN` and Python

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Chris Weibel

Senior Engineer Team Lead and former DBA, SAN administrator, and developer

Photo by mk. s on Unsplash

The Rodney Dangerfield of the CF CLI, show it some respect!

I was assigned to take a look at all the environment variables being used for a foundation. Normally, I would put together a quick query against the Cloud Controller database, but I found this data to be encrypted.

However, you can pull the information from the CF CLI, but you need to know how to log in and loop through the results. A bit of Python, a dancing gopher, and proper course etiquette are all you need.

Grab your putter and head to the first hole!

Hole 1 – Login

Quick and easy, use the cf CLI to log into your desired CF foundation:

cf login

# or 

cf login --sso

After a successful login, the token and other information will be stored in ~/.cf/config.json

Hole 2 – Create Python Script

The script below will use the token from the last step which is stored in ~/.cf/config.json

#!/usr/bin/env python3
import requests
from requests.structures import CaseInsensitiveDict

import sys
import warnings


# Disable SSL Warnings - important for KubeCF
if not sys.warnoptions:
    warnings.simplefilter("ignore")

# Login
system_domain = sys.argv[1]
token = sys.argv[2]

headers = CaseInsensitiveDict()
headers["Accept"] = "application/json"
headers["Authorization"] = token

apps_url = "https://api." + system_domain + "/v3/apps/?per_page=100"

entries = requests.get(apps_url, headers=headers, verify=False).json()

total_results = entries["pagination"]["total_results"]
total_pages = entries["pagination"]["total_pages"]
current_page = 1
apps = {}

while True:
    print("Processing page " + str(current_page) + "/" + str(total_pages))

    for entry in entries["resources"]:

        env_vars_url = entry["links"]["environment_variables"]["href"]
        env_vars = requests.get(env_vars_url, headers=headers, verify=False).json()

        line_label = "app:" + entry["name"]+",env"
        apps[line_label] = []

        for key, value in env_vars["var"].items():
            apps[line_label].append(str(key) + "=" + str(value))


    current_page += 1

    if entries["pagination"]["next"] is None:
        break

    entries = requests.get(entries["pagination"]["next"]["href"], headers=headers, verify=False).json()


for key, value in apps.items():
    print(str(key) + ":" + str(value))

Save this file and call it scrape.py

Hole 3 – Run the Script

This is where the magic of the cf oauth-token happens. After you’ve logged in successfully, the bearer token is stored locally and can be retrieved on-demand, and is also refreshed as needed. Cool, huh? More details on the command can be found at https://cli.cloudfoundry.org/en-US/v6/oauth-token.html

If you clicked on that link and were underwhelmed, welcome to the club and you can be excused for having never heard of the command before. Keep going, you’ll see how valuable it truly is.

Assuming you named the script scrape.py, you can now run it against your foundation; the first parameter is the system domain of your foundation, and the second parameter is the command to retrieve the bearer token:

python3 scrape.py system_url.nip.io "$(cf oauth-token)"

The script will loop through the visible apps and pull back the list of environment variables. Users with cloud_controller.admin or similar permissions will loop through all orgs and spaces; otherwise, it will loop through just the orgs and spaces you have permissions to.

The output will look similar to:

Processing page 1/1
app:my-test-app,env:['MYENV=test']

If you’d like an example of a scraping org, space, and alternate login combinations, I’ve created this example script. The notes at the top include instructions if you’re attempting to run this against a locally deployed KubeCF.

Enjoy! Remember to return your putter and scorecard back to the front desk.

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