AKS audit log integration with Falco

This program is a Go version of the following program: https://github.com/sysdiglabs/aks-audit-log. The purpose of aks-audit-log-go is to receive Kubernetes audit logs and forward them to Falco runtime security tool that can do detections based on runtime security rules for Kubernetes API calls (using the k8s-audit plugin).

Architecture

How program works

There are four packages: main, httpclient, forwarder and eventhub.

forwarder package

This package does two things: (1) it sets the configurations using the environment variables and (2) starts a server to maintain statistics.

eventhub package

This package is responsible for receiving the events from the event log and unmarshalling the event for it to be sent into a post request.

webhook package

This package ensures that POST request to the Falco pod (with k8s-audit plugin) is properly sent.

httpclient package

This package sends the http POST request to the Falco pod (with k8s-audit plugin) pod.

How to run locally

Configuration

There is a .envrc.example file that contains the environment variables to be configured. You can save a copy as .envrc and then source it using source .envrc to load the environment variables into your shell session.

Note: POSTMAXRETRIES, POSTRETRYINCREMENTALDELAY, LOGLEVEL and KEEPALIVE are optional variables. They will default to 5 for POSTMAXRETRIES, 1000 for POSTRETRYINCREMENTALDELAY, "info" for LOGLEVEL and false for KEEPALIVE.

EventHub connection string

The EHUBNAMESPACECONNECTIONSTRING environment variable sets the EventHub connection string.

EventHub name

The EVENTHUBNAME environment variable sets the EventHub name.

Blob storage connection string

The BLOBSTORAGECONNECTIONSTRING environment variable sets the Blob storage connection string.

Blob container name

The BLOBCONTAINERNAME environment variable sets the Blob container name.

Webhook URL

The WEBSINKURL environment variable sets the webhook URL for the Falco pod (with k8s-audit plugin) pod. For example, http://localhost:8765/k8s-audit.

Maximum retries

The POSTMAXRETRIES environment variable sets the maximum number of retries for the POST request to the Falco pod (with k8s-audit plugin) pod.

Retry incremental delay

The POSTRETRYINCREMENTALDELAY environment variable sets the incremental delay between retries for the POST request to the Falco pod (with k8s-audit plugin) pod.

Rate limiter events per seconds

The RATELIMITEREVENTSPERSECONDS environment variable sets the rate limiter for the number of events per second.

Rate limiter burst

The RATELIMITERBURST environment variable sets the rate limiter for the burst.

Log level

The LOGLEVEL environment variable sets what is sent to its log. The following log levels are allowed (from highest to lowest): panic, fatal, error, warn, info, debug and trace.

Keep alive

The KEEPALIVE environment variable sets whether the connection to the webhook URL should be kept alive or not.

Running

Open a terminal and move to the directory for this application.

Build the code: CGO_ENABLED=0 GOOS=linux go build -ldflags="-s" -a -installsuffix cgo .
Run the binary (after building you will have an executable binary file in the current directory): ./aks-audit-log-go

# README