how to do hwclock operations from a container

Product support balenaOS
1

Hi,

Environment:
BalenaOS 2.48.0+rev1 and supervisor 10.8.0 running on a BalenaFin(cm3) in local mode

I am trying to synchronize my BalenaFin system time with hwclock, on receiving a gps message from an external hardware (mqtt message), using my python program running inside a container.

I have tried some settings and I got hwclock command available in the container. I can do now commands like,

/ # hwclock --show
Tue May 19 10:04:22 2020 0.000000 seconds

However it doesn’t have permission to do operations like hwclock --systohc, hwclock --hctosys etc, I am getting an error Operation not permitted. How do I get required permission inside container to do this.

/ # hwclock --hctosys
hwclock: settimeofday: Operation not permitted

I tried following to make the hwclock available in container,

set BALENA_HOST_CONFIG_dtoverlay to "i2c-rtc,ds1307"

add a device to docker-compose.yml

devices:
   - "/dev/rtc:/dev/rtc"

this is my docker-compose.yml

version: '2.1'
volumes:
    system-service:
services:
  mercury-system-service:
    build: ./system-service/
    network_mode: "host"
    volumes:
       - system-service:/app
    devices:
       - "/dev/rtc:/dev/rtc"
  mosquitto:
    image: "eclipse-mosquitto"
    ports:
      - "1883:1883"
    network_mode: "host"

And Dockerfile

Dockerfile

1 Like
3

Hi @chjose,

Have you tried setting privileged: true for mercury-system-service in your docker-compose.yml file to elevate the permission of your container?

Regards,
Carlo

1 Like
5

Thanks @cmfcruz issues got fixed with the solution privileged: true