etherlab_rocker

A rocker extension that installs the EtherCAT Master IgH (EtherLab) userspace library from source inside a Docker image and forwards the master device and configuration into the container.

The extension clones a chosen tag or branch of EtherLab EtherCAT master from https://gitlab.com/etherlab.org/ethercat.git, builds it with --disable-kernel (userspace-only), and installs it under /usr/local/etherlab.

In addition, the /dev/EtherCAT<idx> device is exposed to the container via --device and the EtherLab config/etc/sysconfig/ethercat is bind-mounted (read-only) into the container automatically.

Missing features:

• Multiple EtherCAT devices (multi-master setup);
• EtherLab repos URL as an argument;
• Master launch at startup, i.e., run sudo /etc/init.d/ethercat start in host.

Prerequisites: kernel module on the host

Because this extension builds EtherLab with --disable-kernel, no kernel module is compiled inside the container. The ec_master kernel module must be built and loaded on the host machine before starting the container. The userspace library communicates with the master through the exposed /dev/EtherCAT* device.

Installation

From PyPI

pip install etherlab-rocker

From source (development)

git clone https://github.com/tpoignonec/etherlab_rocker.git

# Virtual environment
sudo apt install python3-venv
python3 -m venv .venv
source .venv/bin/activate

# Install package
pip install -e ./etherlab_rocker

Usage

sudo apt-get install python3-rocker

rocker --etherlab [--etherlab-version <version>] [--ethercat-master-idx <idx>] <base-image> [command]

Arguments

Examples

Basic — install EtherLab stable-1.5 (default) and open a shell:

rocker --etherlab ubuntu:24.04 bash

Use a specific tag or branch:

rocker --etherlab --etherlab-version stable-1.6 ubuntu:24.04 bash

Explicit master device index:

rocker --etherlab --ethercat-master-idx 1 ubuntu:24.04 bash

Note that no value is the same as 0.

Skip installation (use a pre-built image that already has EtherLab):

rocker --etherlab --etherlab-version none my-prebuilt-image bash

Disable device forwarding (build/test only, no hardware):

rocker --etherlab --ethercat-master-idx -1 ubuntu:24.04 bash

Test the connection to the EtherCAT master

Once inside the container:

# List slaves on the bus
ethercat slaves

# Show master state
ethercat master