Pi keeps flashing "you are now connected to "

General
1

One of my Pi’s is flashing this every maybe 10 seconds, with different combinations of letters and numbers:

image

Where do I look for the problem? Since the name of the network changes so rapidly, I can’t use docker network inspect I think, because I keep getting Error response from daemon: network vethe856f53 not found

This is latest version of everything.

Edit: I managed to narrow it down to Node RED, this is what the Docker Compose file looks like:

services:
node-red:
build:
dockerfile_inline: |
FROM  nodered/node-red:4.0.9-debian
USER root
RUN apt-get update 
&& apt-get install -y --no-install-recommends iputils-ping sshpass openssh-client
USER node-red
container_name: Node-RED
privileged: true
restart: no
group_add:
- "20"
- "46"
environment:
- TZ=Europe/Oslo

network_mode: host 
devices:
  - /dev/serial/by-id/usb-RFXCOM_RFXtrx433_A12HDOV8-if00-port0:/dev/ttyUSB0
volumes:
  - /media/pi/Docker/Docker-Compose/Node-RED/Data:/data
  - /home/pi/Sikkerhetskopier:/home/pi/Sikkerhetskopier
  - /home/pi/.ssh/known_hosts:/usr/src/node-red/.ssh/known_hosts:ro
  - /media/pi/Docker/Docker-Compose:/home/pi/Docker-Compose:ro
  - /home/pi/Driftskontroll:/home/pi/Driftskontroll:ro
  - type: bind
    source: /home/pi/Node-RED-omstarter.txt
    target: /home/pi/Node-RED-omstarter.txt

Nothing funky about the network, it’s simply host. I’m using that version of Node-RED because that’s the only one that works with my rfxTRX433, and I need the iputils-ping sshpass openssh-client for interactions with the host and other Pi’s.

Edit: I think I can use the latest Debian version on this Pi, I am trying that now. It seems not to throw the message, I’ll keep an eye on it and add to this thread if it doesn’t help.

2

Use 3 backticks in front and after code/config to preserve spacing, which in important in yaml.

3

Sorry I was using the “Preformatted text” button, I had the impression that it did just that.

4

I don’t think the compose file will help in this case, but thanks for sharing it. If you see constantly changing inzterface names appearing s “connected”, my guess is that one of your containrs are failing and restarting so its network interface is recreated with a different name every time.

Have you tried checking the output of docker ps -a? Running docker ps could also be enough as you would see if some containers disappear from the list. If it happens to quickly, you can still check when the container was started.

If the container is failing, trying docker logs containername could also show why it restarts so often.

It was, but it looks like the indentation was broken already and the forum can’t fix that.

5

What you see is not a network, it’s a virtual network interface. It is used to connect the isolated network of a container with a virtual network interface on the host, which itself is attached to a network bridge. Each veth interface belongs to a single container network interface - it is like a wire between those two interfaces.

You can not list the veth interfaces with docker network insoect, though you should see them with ip a and they should have br-<network id> in the first line before status UP. This network id on the other hand can be inspected. This would allow to pinpoint which network the container is attached to, and once you know this, you should be able to know which compose file created the network - and most likely crated the container that restarts in a loop.

Though, since your node red container uses network_mode: host it should share the network namespace of the host, and it will not have a veth interface on the host.

I second the theory that at least one container is probably going wild and restarting all the time.

7

Thanks for the answers! My “edit” in the first post was correct, updating to the latest version of Node-RED fixed it. All three containers on the Pi have now been running for 42 hours and there hasn’t been any of the network flashing when I have looked at it over VNC. So I think this was probably some incompatibility with an update of the Pi’s operating system and the Node-RED container that was running, but I see no point in trying to find out as long as it works. :grin:

Edit: I updated another one of my Pi’s and ran into exactly the same thing! So it’s most definitively because the version of Node-RED Debian does not work with something in a Rasberry Pi OS update, I guess it’s likely that it’s related to a docker update. But this time I won’t have to wonder, I’ll just upgrade the Docker Compose file to point to “Latest”.