Thanks to sdelrio/rpi-hostap and dedosmedia/rpi-hostap

Incorporated dedosmedia/rpi-hostap changes to support rp3, and made some minor tweaks so that older usb dongles (B/G only) will also work

Docker container stack: hostap + dhcp server

Designed to work on Raspberry Pi (arm) using as base image alpine linux (very little size).

Idea

Since my last change on ISP, they put a cable modem with a horrible Wireless, it drops lots of packets, and I didn't want to put an extra AP or wireless router.

Most of the time use wireless devices on same room so I decided to try to convert my current Pi on a small Access Point using a small USB dongle.

Made minor changes to support for older USB dongles that only support G and now can pass IEEE80211N=0. Also example below shows passing HT_CAPAB values for older USB wifi standards.

Requirements

On the host system, the ralink firmware (in my case) should be installed so you can use it on AP mode. On debian/raspbian:

apt-get install firmware-ralink

Make sure your USB support AP mode:

# iw list
...
        Supported interface modes:
                 * IBSS
                 * managed
                 * AP
                 * AP/VLAN
                 * WDS
                 * monitor
                 * mesh point
...

Set country regulations, for excample, to Spain set:

# iw reg set ES
country ES: DFS-ETSI
        (2400 - 2483 @ 40), (N/A, 20), (N/A)
        (5150 - 5250 @ 80), (N/A, 23), (N/A), NO-OUTDOOR
        (5250 - 5350 @ 80), (N/A, 20), (0 ms), NO-OUTDOOR, DFS
        (5470 - 5725 @ 160), (N/A, 26), (0 ms), DFS
        (57000 - 66000 @ 2160), (N/A, 40), (N/A)

Build / run

For modification, testings, etc.. there is already a Makefile. So you can make run to start a sample ssid with a simple password.

I've already uploaded the image to docker hubs, so you can run it from ther like this:

sudo docker run -d -t \
  -e INTERFACE=wlan0 \
  -e CHANNEL=6 \
  -e SSID=runssid \
  -e APADDR=192.168.254.1 \
  -e SUBNET=192.168.254.0 \
  -e WPA_PASSPHRASE=passw0rd \
  -e IEEE80211N=0 \
  -e HT_CAPAB=[HT20][SHORT-GI-20] \
  -e OUTGOINGS=eth0 \
  --privileged \
  --net host \
  georgezero/rpi-hostap:latest

rpi3:

sudo docker run -d -t \
  -e INTERFACE=wlan0 \
  -e CHANNEL=6 \
  -e SSID=runssid \
  -e APADDR=192.168.254.1 \
  -e SUBNET=192.168.254.0 \
  -e WPA_PASSPHRASE=passw0rd \
  -e IEEE80211N=1 \
  -e HT_CAPAB=[HT40][SHORT-GI-20][DSSS_CCK-40] \
  -e OUTGOINGS=eth0 \
  --privileged \
  --net host \
  georgezero/rpi-hostap:latest

To test interactively, you may want to start a tmux session and then:

sudo docker run -it \
  -e INTERFACE=wlan0 \
  -e CHANNEL=6 \
  -e SSID=runssid \
  -e APADDR=192.168.254.1 \
  -e SUBNET=192.168.254.0 \
  -e WPA_PASSPHRASE=passw0rd \
  -e IEEE80211N=0 \
  -e HT_CAPAB=[HT20][SHORT-GI-20] \
  -e OUTGOINGS=eth0 \
  --privileged \
  --net host \
  georgezero/rpi-hostap:latest

rpi3:

sudo docker run -it \
  -e INTERFACE=wlan0 \
  -e CHANNEL=6 \
  -e SSID=runssid \
  -e APADDR=192.168.254.1 \
  -e SUBNET=192.168.254.0 \
  -e WPA_PASSPHRASE=passw0rd \
  -e IEEE80211N=1 \
  -e HT_CAPAB=[HT40][SHORT-GI-20][DSSS_CCK-40] \
  -e OUTGOINGS=eth0 \
  --privileged \
  --net host \
  georgezero/rpi-hostap:latest

But before this, hostap usually requires that wlan0 interface to be already up, so before docker run take the interface up:

/sbin/ifconfig wlan0 192.168.254.1/24 up

Also you should have a driver to enable hostap on your USB wifi

apt-get install firmware-ralink

Todo

Improve README.md

georgezero / rpi-hostap