balena-labs-projects/wifi-connect

The wifi-connect block is a docker image that runs wifi-connect which is a utility for dynamically setting the WiFi configuration on a Linux device via a captive portal.

Usage

To use this image, create a service in your docker-compose.yml file as shown below:

version: "2.1"

services:
  wifi-connect:
    image: bh.cr/balenalabs/wifi-connect-<device arch name>
    restart: always
    network_mode: host
    privileged: true
    labels:
      io.balena.features.dbus: "1"
      io.balena.features.firmware: "1"

You can also set your docker-compose.yml to build a Dockerfile.template file, and use the build variable %%BALENA_ARCH%% so that the correct image is automatically built for your device arch (see supported architectures):

docker-compose.yml:

version: "2.1"

services:
  wifi-connect:
    build: ./
    restart: always
    network_mode: host
    privileged: true
    labels:
      io.balena.features.dbus: "1"
      io.balena.features.firmware: "1"

Dockerfile.template

FROM bh.cr/balenalabs/wifi-connect-%%BALENA_ARCH%%

Supported Architectures

bh.cr/balenalabs/wifi-connect is built for the following archs:

• aarch64
• armv7hf
• amd64
• rpi

Customisation

bh.cr/balenalabs/wifi-connect can be configured via the following variables:

Environment Variable	Default	Description
PORTAL_DHCP_RANGE	192.168.42.2,192.168.42.254	DHCP range of the captive portal WiFi network
PORTAL_GATEWAY	192.168.42.1	Gateway of the captive portal WiFi network
PORTAL_LISTENING_PORT	80	Listening port of the captive portal web server
PORTAL_INTERFACE	first managed interface	Wireless network interface to be used by WiFi Connect
PORTAL_PASSPHRASE	no passphrase	WPA2 Passphrase of the captive portal WiFi network
PORTAL_SSID	WiFi Connect	SSID of the captive portal WiFi network
ACTIVITY_TIMEOUT	0 - no timeout	Exit if no activity for the specified timeout (seconds)
CHECK_CONN_FREQ	120 - specified number of seconds	The frequency with which to check if the device is connected to the internet.
VERBOSE	none	Set false to silence the logging messages

You can refer to the docs on how to set environment or service variables

Alternatively, you can set them in the docker-compose.yml or Dockerfile.template files.

Changing the logic in the start.sh file

When the container run, it executes the start.sh script. If the default logic does not suit your use case, you can adapt the script and replace the file in the image. You will have to set up the Dockerfile.template file as illustrated above and use the COPY directive and replace the file at /start.sh.

Note: This is a minimal image containing only the required dependencies and busybox. You will have to make use of the minimal toolset that busybox provides. Available commands.