Create Falco rule from Anchore policy result

This integration creates a rule for Sysdig Falco based on Anchore policy result. So that when we will try to run an image which has a stop final action result in Anchore, Falco will alert us.

Getting started

Prerequisites

For running this integration you will need:

Python 3.6
pipenv
An anchore-engine running

Configuration

This integration uses the same environment variables that anchore-cli:

ANCHORE_CLI_USER: The user used to conect to anchore-engine. By default is admin
ANCHORE_CLI_PASS: The password used to connect to anchore-engine.
ANCHORE_CLI_URL: The url where anchore-engine listens. Make sure does not end with a slash. By default is http://localhost:8228/v1
ANCHORE_CLI_SSL_VERIFY: Flag for enabling if HTTP client verifies SSL. By default is true

Running

This is a Python program which generates a Falco rule based on anchore-engine information:

pipenv run python main.py

And this will output something like:

- macro: anchore_stop_policy_evaluation_containers
  condition: container.image.id in ("8626492fecd368469e92258dfcafe055f636cb9cbc321a5865a98a0a6c99b8dd", "e86d9bb526efa0b0401189d8df6e3856d0320a3d20045c87b4e49c8a8bdb22c1")

- rule: Run Anchore Containers with Stop Policy Evaluation
  desc: Detect containers which does not receive a positive Policy Evaluation from Anchore Engine.

  condition: evt.type=execve and proc.vpid=1 and container and anchore_stop_policy_evaluation_containers
  output: A stop policy evaluation container from anchore has started (%container.info image=%container.image)
  priority: INFO
  tags: [container]

You can save that output to /etc/falco/rules.d/anchore-integration-rules.yaml and Falco will start checking this rule.

As long as information in anchore-engine can change, it's a good idea to run this integration periodically and keep the rule synchronized with anchore-engine policy evaluation result.

Tests

As long as there are contract tests with anchore-engine, it needs a working anchore-engine and its environment variables.

pipenv install -d
pipenv run mamba --format=documentation

Docker support

Build the image

docker build -t sysdig/anchore-falco .

Running the image

An image exists on DockerHub, its name is sysdig/anchore-falco.

So you can run directly with Docker:

docker run --rm -e ANCHORE_CLI_USER=<user-for-custom-anchore-engine> \
                -e ANCHORE_CLI_PASS=<passsword-for-user-for-custom-anchore-engine> \
                -e ANCHORE_CLI_URL=http://<custom-anchore-engine-host>:8228/v1 \
                sysdig/anchore-falco

And this will output the Falco rule based on custom-anchore-engine-host.

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