go-ipocalypse

A tool for testing network behavior by deploying multiple containers with DHCP-assigned IP addresses to a local network.

Overview

go-ipocalypse creates a macvlan network and launches containers that:

• Obtain IP addresses via DHCP
• Can be configured with or without internet access
• Run custom testing workloads
• Scale up until the IP address space is exhausted

Prerequisites

• Linux host with Docker installed
• sudo access (required for network configuration)
• ipcalc package (will be automatically installed if missing)

Installation

git clone https://github.com/yourusername/go-ipocalypse
cd go-ipocalypse
go build

Usage

Basic usage:

sudo ./ipocalypse

Command Options

• -dockerfiles (optional): Comma-separated list of directories containing Dockerfiles.
  • Must start with "ipocalypse".
  • If not specified, automatically discovers all ipocalypse* directories.
• -workers (default: 5): Number of concurrent container launch workers
• -internet (default: false): Enable internet access for containers
  
  ipocalypse_basic_image has no functionality beyond connecting to the local network. Add your own custom Dockerfiles to additional directories to deploy containers with other workloads. Additional directories must start with ipocalypse_ to be discovered. Example: ipocalypse_<name_of_workload>.

Example with Options & Specific Dockerfile Directories:

sudo ./ipocalypse -dockerfiles ipocalypse_basic_image,ipocalypse_workload1 -workers 10 -internet

Network Configuration

ipocalypse will:

1. Create a Docker macvlan network "ipocalypse_net"
2. Set up a host macvlan interface for container communication
3. Configure NAT if internet access is enabled
4. Launch containers using images from all ipocalypse* directories until ip addresses are exhausted

Cleanup

To stop all running containers:

docker stop $(docker ps -a -q)

To remove all containers:

docker rm $(docker ps -a -q)

To clean up the network configuration:

sudo utils/cleanup_network.sh

Creating Custom Images

1. Create a new directory starting with "ipocalypse"
2. Add a Dockerfile and any required scripts
3. Ensure the container runs continuously and handles DHCP configuration

Example basic image structure:

ipocalypse_basic_image/
├── Dockerfile
└── entrypoint.sh

Container DCHP Setup:

The entrypoint.sh for the ipocalypse_basic_image ensures each container properly joins the network and maintains its network connection by handling:

1. Network Setup:

• Detects and configures the container's network interface
• Attempts to obtain an IP address via DHCP (tries up to 3 times)
• Handles cleanup of DHCP leases on container shutdown

2. Monitoring:

• Keeps the container running indefinitely
• Logs network status every 60 seconds
• Shows IP address and routing information

3. Error Handling:

• Provides detailed debugging output
• Gracefully handles failures in interface detection or DHCP
• Implements proper signal handling for clean container shutdown

Configure functionality for other container images by copying this script to new ipocalypse_* Dockerfile directories and modifying the script as needed.