flash
Command line script to flash SD card images of any kind.
Note that for some devices (e.g. Raspberry Pi), at the end of the flashing process the tool tries to customize the SD card e.g. it configures a hostname or WiFi. And with a cloud-init enabled image you can do much more like adding users, SSH keys etc.
The typical workflow looks like this:
- Run
flash https://github.com/hypriot/image-builder-rpi/releases/download/v1.12.0/hypriotos-rpi-v1.12.0.img.zip
- Insert SD card to your notebook
- Press RETURN
- Eject SD card and insert it to your Raspberry Pi - done!
This script can
- download a compressed SD card from the internet or from S3
- use a local SD card image, either compressed or uncompressed
- wait until a SD card is plugged in
- search for a SD card plugged into your Computer
- show progress bar while flashing (if
pv
is installed) - copy an optional cloud-init
user-data
andmeta-data
file into the boot partition of the SD image - copy an optional
config.txt
file into the boot partition of the SD image (eg. to enable onboard WiFi) - copy an optional
device-init.yaml
oroccidentalis.txt
file into the boot partition of the SD image (for older HypriotOS versions) - copy an optional custom file into the boot partition of the SD image
- optional set the hostname of this SD image
- optional set the WiFi settings as well
- play a little sound after flashing
- unplugs the SD card
At the moment only Mac OS X and Linux is supported.
Installation
Download the appropriate version for Linux or Mac with this command
curl -LO https://github.com/hypriot/flash/releases/download/2.7.2/flash
chmod +x flash
sudo mv flash /usr/local/bin/flash
Install Dependencies
The flash
script needs optional tools
curl
- if you want to flash directly with an HTTP URLaws
- if you want to flash directly from an AWS S3 bucketpv
- to see a progress bar while flashing with thedd
commandunzip
- to extract zip files.hdparm
- to run the program
Mac
brew install pv
brew install awscli
Linux (Debian/Ubuntu)
sudo apt-get install -y pv curl python-pip unzip hdparm
sudo pip install awscli
Usage
$ flash --help
usage: flash [options] [name-of-rpi.img]
Flash a local or remote Raspberry Pi SD card image.
OPTIONS:
--help|-h Show this message
--bootconf|-C Copy this config file to /boot/config.txt
--config|-c Copy this config file to /boot/device-init.yaml (or occidentalis.txt)
--hostname|-n Set hostname for this SD image
--ssid|-s Set WiFi SSID for this SD image
--password|-p Set WiFI password for this SD image
--clusterlab|-l Start Cluster-Lab on boot: true or false
--device|-d Card device to flash to (e.g. /dev/disk2)
--force|-f Force flash without security prompt (for automation)
--userdata|-u Copy this cloud-init config file to /boot/user-data
--metadata|-m Copy this cloud-init config file to /boot/meta-data
--file|-F Copy this custom file to /boot
Configuration
The strength of the flash tool is that it can insert some configuration files that gives you the best first boot experience to customize the hostname, WiFi and even user logins and SSH keys automatically.
cloud-init
With HypriotOS v1.7.0 and higher the options --userdata
and --metadata
can be used to copy both cloud-init config files into the FAT partition.
This is an example how to create our default user with a password.
#cloud-config
# vim: syntax=yaml
#
hostname: black-pearl
manage_etc_hosts: true
users:
- name: pirate
gecos: "Hypriot Pirate"
sudo: ALL=(ALL) NOPASSWD:ALL
shell: /bin/bash
groups: users,docker,video
plain_text_passwd: hypriot
lock_passwd: false
ssh_pwauth: true
chpasswd: { expire: false }
package_upgrade: false
Please have a look at the sample
folder, our guest blogpost Bootstrapping a Cloud with Cloud-Init and HypriotOS or at the cloud-init documentation
how to do more things like using SSH keys, running additional commands etc.
config.txt
The option --bootconf
can be used to copy a config.txt
into the SD image
before it is unplugged.
With this option it is possible to change some memory, camera, video settings etc. See the config.txt documentation at raspberrypi.org for more details.
The boot config file config.txt has name/value pairs such as:
max_usb_current=1
hdmi_force_hotplug=1
device-init.yaml
For HypriotOS older than v1.7.0 the option --config
can be used to copy a
device-init.yaml
into the SD image before it is unplugged. This YAML file can
be read by newer HyperiotOS SD images.
The config file device-init.yaml should look like
hostname: black-pearl
wifi:
interfaces:
wlan0:
ssid: "MyNetwork"
password: "secret_password"
If you don't want to set any wifi settings, comment out or remove the wlan0, ssid and password.
fake-hwclock.data
HypriotOS 1.12.0 and higher has the /etc/fake-hwclock.data
file symlinked to the boot partition. Flash tool updates this timestamp with the current time (UTC timezone). This fixes problems running commands that communicate with the internet with a wrong initial date on first boot.
Use cases
Flash a compressed SD image from the internet
flash https://github.com/hypriot/image-builder-rpi/releases/download/v1.12.0/hypriotos-rpi-v1.12.0.img.zip
Flash and change the hostname
This works only for SD card images that already have occi
installed.
flash --hostname mypi hypriot.img
Then unplug the SD card from your computer, plug it into your Pi and boot your Pi. After a while the Pi can be found via Bonjour/avahi and you can log in with
Onboard WiFi
The options --userdata
and --bootconf
must be used to disable UART and enable onboard WiFi for Raspberry Pi 3 and Pi 0. For external WiFi sticks you do not need to specify the -bootconf
option.
flash --userdata sample/wlan-user-data.yaml --bootconf sample/no-uart-config.txt hypriotos-rpi-v1.12.0.img
Automating flash
For non-interactive usage, you can predefine the user input in the flash command with the -d
and -f
options:
flash -d /dev/mmcblk0 -f hypriotos-rpi-v1.12.0.img
Development
Pull requests and other feedback is always welcome. The flash
tool should fit
our all needs and environments.
To develop the flash scripts you need either a Linux or macOS machine to test locally. On a Mac you can use Docker to run the Linux tests in a container and if you dare you can run the macOS tests directly. On a Linux machine you can not test the macOS variant directly. But in every case you can send a pull request and push code to GitHub and the CI pipeline with CircleCI (Linux) and TravisCI (macOS) will test your code for both platforms.
Local development
The flash script are checked with the shellcheck
static analysis tool.
The integration tests can be run locally on macOS or Linux. We use BATS which is installed with NPM package. So you would need Node.js to setup a local development environment. As the flash script runs dd
and some commands with sudo
it is recommended to use the isolated test environment with Docker or run this local tests in a macOS / Linux VM.
npm install
npm test
Isolated tests with Docker
If you do not want to install all these development tools (shellcheck, bats, node) and don't trust the flash script enough, you can use Docker instead and run the shellcheck and integration tests in a much safer test environment.
All you need is Docker and make
installed to run the following tests.
Shellcheck
The flash script are checked with the shellcheck static analysis tool.
make shellcheck
Integration tests
The flash script also have BATS integration tests. You don't have to install everything on your development machine. It should be enough to test the Linux variant in a Docker container and then run the macOS tests with TravisCI.
make test
Test Linux from Mac
For manual tests of the Linux version on a Mac there is a Vagrant environment. It can be used to investigate Linux problems when you don't have a baremetal Linux machine. With some help I found a way to spin up a VirtualBox Vagrant box with Ubuntu that maps the internal Apple SD card reader into the VM. Thanks to Flexshot for the helper functions I found in NextThingCo/CHIP-SDK#15.
Check the vendor ID and product ID in "About this Mac" -> System Report ... ->
Card Reader. I found the vendor ID 0x05ac and product ID 0x8406 can be found in
the Vagrantfile
.
vagrant up --provider virtualbox
vagrant ssh
cd /vagrant
./flash hypriotos-rpi-v1.12.0.img.zip