Networking tools
Previously, Raspberry Pis used a file called wpa_supplicant.conf
to handle wifi network connections. This is not longer the case. Modern Raspberry Pi software, including the Pioreactor, doesn't use wpa_supplicant.conf
at all. Instead, the tool nmcli
replaces it. Don't follow tutorials that use wpa_supplicant.conf
.
General networking tools
The main "entry point" for networking on the Pioreactor (and Raspberry Pi's in general) is the tool nmcli
. This controls discovering networks, connecting to them, and editing connections. For example, running nmcli con
will diplay a list of possible networking connections, and connected ones in green.
Connecting to a wifi network using nmcli
You can first discover all the visible networks with:
sudo nmcli d wifi list
If you see your network on the list, then run:
sudo nmcli device wifi connect <ssid name> password <ssid password> ifname wlan0
(If you get a "Can't find" error, try running the above list
command again.)
Connecting to multiple networks simultaneously
First, some terminology and understanding for us: a computer, like a Pi, has networking interfaces. For example, the onboard wifi on RPi’s is one such interface. The larger, model Bs, have an ethernet connector, which is another interface. Each interface can connect to 0 or 1 networks.
In order to connect to multiple networks, you need a Raspberry Pi with multiple interfaces. You can add interfaces with devices like a USB wifi device.
To see what your current interfaces are doing, use:
nmcli device
The right hand side shows your connected interfaces. For example, if have a ethernet connection to a router, you'll see an eth0
connection active. If you have an additional wifi hardware device attached to your Pi, you'll see wlan1
.
To connect to another wifi network using an external wlan1
interface, use:
sudo nmcli device wifi connect <ssid name> password <ssid password> ifname wlan1
If your leader is connected to multiple networks A
and B
, and you access the UI over network A
, but your workers access over network B
, the leader is in the position called a "gateway". You'll need to make some configuration changes to your cluster. Since the leader is attached to networks A
and B
, it has two IPs (use hostname -I
to see all the ips), let's call them ipA
and ipB
respectively.
- Access the configuration in the UI.
- In the shared config.ini, edit the
[mqtt]
broker
field to be equal toipA
. Also edit theleader_address
to beipB
. - In each of the workers (including the leader's config.ini, if it's a worker), add the following:
[mqtt]
broker=ipB
You may need to restart your cluster for these to take full effect.
Starting the Pioreactor local access point using nmcli
Note that you can only have 1 network connection for each network interface. So if you have only 1 wifi device (by default, RPi's only have 1 wifi device on them -> only 1 wifi interface), the following will replace any existing wifi connection.
sudo nmcli con up PioreactorAP
Changing leader_address
and MQTT broker
in your config.ini
You may need to change the leader_address
in your config.ini: this is the address where workers will communicate with your leader.
Likewise, you may need to change the mqtt broker
in your config.ini for the same reason. It may be required to change it in the unit specific config.inis.
[mqtt]
broker=leader.local
Changing web UI port from 80
to something else
To change the web UI port from the default of 80
, following these instructions:
-
SSH into your leader Pioreactor.
-
We'll edit the lighttpd configuration first:
sudo nano /etc/lighttpd/lighttpd.conf
and find the line starting with
server.port
. Change this to something else (preferably not a value below 1024). Save and exit. -
Restart lighttpd with:
sudo systemctl restart lighttpd.service
You should be able to access the web UI only on http://
leader name
:new port
, for example: http://leader.local:8080 -
In your configuration, under the
[ui]
section, change theport
option from80
to your new port value. Save. You may need to restart your cluster for this new port to propagate to all machines correctly.
Connecting to eduroam
This is a work-in-progress, but here's one example.
Common questions
My Pioreactor activities start very slowly from the UI
It is possible that your mDNS is being blocked or restricted. If possible, log into your router and enable settings that allow "multicast", or "mDNS", or "IGMP proxing". If you are using a the builtin local access point, this solution is not the correct one.
Also, if you are able to provide a permanent IPv4 address to your leader, you can get a significant performance boost by setting the configuration some config parameters to the IPv4 address.
[cluster.topology]
# below is an example, your IPv4 may differ:
leader_address=192.168.0.3
[mqtt]
broker_address=192.168.0.3