Python 3 script for detecting Cloud Foundry droplets using the java buildpack (for log4j reasons).

java_app_sniffer.py

#!/usr/bin/env python3

# Usage:
# ./java_app_sniffer.py
#
# Environment Variables (optional):
# PAGE_SIZE - Specifies how many droplets to retrieve per API request (Default: 5000)
# BUILDPACK_NAME - Specifies the name of the java buildpack for targeted environment (Default: java_buildpack)
#
# Note:
# - Requires cf CLI to be installed and logged in as user with global read access

import collections
import json
import os
import shutil
import subprocess
import sys


droplet_data = collections.defaultdict(list)


def get_page(page: int, page_size: str, buildpack_name: str) -> bool:
    out = subprocess.run(
        ["cf", "curl", f"/v3/droplets?per_page={page_size}&page={page}"],
        text=True,
        capture_output=True,
    )

    if out.returncode != 0:
        sys.exit(out.stderr)

    response = json.loads(out.stdout)
    pagination = response.get("pagination")
    resources = response.get("resources")

    if pagination == None or resources == None:
        sys.exit("Invalid response from API " + out.stdout)

    for droplet in resources:
        try:
            if droplet.get("lifecycle").get("type") == "docker":
                continue

            buildpacks = droplet.get("buildpacks")
            buildpack_names = [buildpack.get("name") for buildpack in buildpacks]

            if buildpack_name in buildpack_names:
                app_guid = (
                    droplet.get("relationships").get("app").get("data").get("guid")
                )

                droplet_data[app_guid].append(
                    {
                        "droplet_guid": droplet.get("guid"),
                        "buildpacks": buildpacks,
                    }
                )
        except BaseException as err:
            print("Error parsing " + json.dumps(droplet))
            raise

    return pagination.get("next") != None


def display_results():
    app_title = "App Guid"
    droplet_title = "Droplet Guid"
    buildpacks_title = "Buildpacks"
    print(f"\n{app_title:40}{droplet_title:40}{buildpacks_title:100}")
    for app_guid, droplets in droplet_data.items():
        for droplet in droplets:
            try:
                droplet_guid = droplet.get("droplet_guid")
                buildpacks = ",".join(
                    [
                        "=".join(
                            (
                                str(buildpack.get("name", "unknown")),
                                str(buildpack.get("version", "unknown")),
                            )
                        )
                        for buildpack in droplet.get("buildpacks")
                    ]
                )
                print(f"{app_guid:40}{droplet_guid:40}{buildpacks:100}")
            except BaseException as err:
                print("Error displaying " + json.dumps(droplet))
                raise


def main():
    if not shutil.which("cf"):
        print("Requires CF CLI")

    print(
        "Make sure you are logged in as a user with global read permissions (admin, admin_read_only, or global_auditor)."
    )

    page_size = os.getenv("PAGE_SIZE", "5000")
    buildpack_name = os.getenv("BUILDPACK_NAME", "java_buildpack")

    page = 1
    get_more_pages = True

    while get_more_pages:
        get_more_pages = get_page(page, page_size, buildpack_name)
        page = page + 1

    display_results()


if __name__ == "__main__":
    main()


# Copyright 2021 Greg Cobb

# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:

# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.

#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
#   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
#   DEALINGS IN THE SOFTWARE.