mender-convert

Mender is an open source over-the-air (OTA) software updater for embedded Linux devices. Mender comprises a client running at the embedded device, as well as a server that manages deployments across many devices.

This repository contains mender-convert, which is used to convert pre-built disk images (Debian, Ubuntu, Raspbian, etc) to a Mender compatible image by restructuring partition table and injecting the necessary files.

For a full list of tested devices and images please visit Mender Hub. If your device and image combination is not listed as supported, this does not necessarily mean that it will not work, it probably just means that no one has tested and reported it back and usually only small tweaks are necessary to get this running on your device.

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Requisites

mender-convert is supported on the following development platform(s):

- Ubuntu 22.04 x86, 64bit

Other platforms may work, but are not under active testing. Patches to add additional platforms or fix compatibility issues are welcome.

The storage used during the process, specifically the work directories (usually below the clone of mender-convert) and the output directory should be located on local, Unix-style filesystem. Using network storage or emulated filesystems might cause permission or owner issues.

Getting started

To start using Mender, we recommend that you begin with the Getting started section in the Mender documentation.

For more detailed information about mender-convert please visit the Debian family section in the Mender documentation.

Included configurations

Core configurations

These configurations are officially supported.

Configuration	Supported OS / hardware
generic_x86-64_config	Generic x86, 64bit distribution use this as a starting point only!
raspberrypi0w_config	RaspberryPi 0w, Raspbian 32bit
raspberrypi3_config	RaspberryPi 3, Raspbian 32bit
raspberrypi4_bullseye_32bit_config	RaspberryPi 4, Raspberry Pi OS "bullseye" 32bit
raspberrypi4_bullseye_64bit_config	RaspberryPi 4, Raspberry Pi OS "bullseye" 64bit
raspberrypi4_bookworm_32bit_config	RaspberryPi 4, Raspberry Pi OS "bookworm" 32bit
raspberrypi4_bookworm_64bit_config	RaspberryPi 4, Raspberry Pi OS "bookworm" 64bit
raspberrypi4_ubuntu_config	RaspberryPi 4, Ubuntu 32bit

Contributed configurations

These configurations have been submitted by community contributors.

Configuration	Supported OS / hardware
comfile_pi_config	Comfile Pi, Raspbian 32bit
rockpro64_emmc_config	RockPro64, Debian 32bit on internal eMMC storage
rockpro64_sd_config	RockPro64, Debian 32bit on external SD card storage

Example usage: Raspberry Pi 4, Raspberry Pi OS 64bit

Prepare image and configuration

The following steps give a quick start using Raspbian. For a more detailed guide, especially concerning version compatibilities, please visit the the corresponding thread on the Mender Hub.

Download the raw Raspberry Pi disk image into a subdirectory input:

mkdir -p input
cd input
wget https://downloads.raspberrypi.com/raspios_lite_arm64/images/raspios_lite_arm64-2024-07-04/2024-07-04-raspios-bookworm-arm64-lite.img.xz

Extract the raw Raspberry Pi disk image:

unzip 2024-07-04-raspios-bookworm-arm64-lite.img.xz
INPUT_DISK_IMAGE=$(ls *raspios-bookworm*.img)
cd ..

Bootstrap the demo rootfs overlay that is configured to connect to a Mender server with polling intervals set appropriately for demonstration purposes. There are three scripts here to support the Mender demo server, the Mender production server, and Mender Professional.

NOTE! Only run one of these three steps depending on the server type you are implementing.

Using hosted Mender

./scripts/bootstrap-rootfs-overlay-hosted-server.sh \
    --output-dir ${PWD}/input/rootfs_overlay_demo \
    --tenant-token "Paste token from Mender Professional"

Using the Mender demo server

./scripts/bootstrap-rootfs-overlay-demo-server.sh \
    --output-dir ${PWD}/input/rootfs_overlay_demo \
    --server-ip 192.168.1.1

Using the Mender on-premise server

./scripts/bootstrap-rootfs-overlay-production-server.sh \
    --output-dir ${PWD}/input/rootfs_overlay_demo \
    --server-url https://foobar.mender.io \
    [ --server-cert ~/server.crt ]

Docker environment for mender-convert

To make using mender-convert easier, a reference setup using a Docker container is provided.

You need to install Docker Engine to use this environment.

Build the mender-convert container image

Build a container with all required dependencies for mender-convert:

./docker-build

This will create a container image with the name mender-convert which you can use to run mender-convert without polluting your host environment with the necessary dependencies.

Use the mender-convert container image

Run mender-convert from inside the container with your desired options, e.g.

mkdir -p input/image
cp $PATH_TO_DISK_IMAGE/$INPUT_DISK_IMAGE input/image

mkdir -p input/config
cp $PATH_TO_MY_OWN_CONFIG/$CUSTOM_CONFIG input/config

MENDER_ARTIFACT_NAME=release-1 ./docker-mender-convert \
   --disk-image input/image/$INPUT_DISK_IMAGE \
   --config configs/raspberrypi4_bookworm_64bit_config \
   --config input/config/$CUSTOM_CONFIG \
   --overlay input/rootfs_overlay_demo

The container will use the work/ directory as a temporary area to unpack and customize the image's content. You can customize the work directory path by setting the WORK_DIRECTORY env variable. To reduce the time required to perform the conversion, you can use tempfs or ramfs mount points.

Conversion will take 10-30 minutes, depending on image size and resources available. You can watch log/convert.log.XXXXX for progress and diagnostics information. The exact log file path is printed before the conversion starts.

After it finishes, you can find your images in the deploy directory on your host machine!

Troubleshooting

A continuously expanded list of possible problems and how to address those is maintained in the Mender documentation

Using mender-convert without Docker

In order to be able to manipulate and create filesystem and disk images, mender-convert has a few dependencies, and their version and name vary between Linux distributions. Here is an example of how to install the dependencies on a Debian based distribution:

sudo apt install $(cat requirements-deb.txt)

Start the conversion process with:

MENDER_ARTIFACT_NAME=release-1 ./mender-convert \
   --disk-image input/$INPUT_DISK_IMAGE \
   --config configs/raspberrypi4_bookworm_64bit_config \
   --overlay input/rootfs_overlay_demo

NOTE! You will be prompted to enter sudo password during the conversion process. This is required to be able to loopback mount images and for modifying them. Our recommendation is to use the provided Docker container, to run the tool in an isolated environment.

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Contributing

We welcome and ask for your contribution. If you would like to contribute to Mender, please read our guide on how to best get started contributing code or documentation.

License

Mender is licensed under the Apache License, Version 2.0. See LICENSE for the full license text.

Security disclosure

We take security very seriously. If you come across any issue regarding security, please disclose the information by sending an email to [email protected]. Please do not create a new public issue. We thank you in advance for your cooperation.

Connect with us

• Join the Mender Hub discussion forum
• Follow us on Twitter. Please feel free to tweet us questions.
• Fork us on Github
• Create an issue in the bugtracker
• Email us at [email protected]
• Connect to the #mender IRC channel on Libera

Authors

Mender was created by the team at Northern.tech AS, with many contributions from the community. Thanks everyone!

Mender is sponsored by Northern.tech AS.