Docker Compose - give access to docker.sock before running (Telegraf) - docker

Question

UPDATE:
I've tried implementing the accepted answer from here Telegraf can not connect to Docker sock like this in my docker compose file:
telegraf3:
image: telegraf
user: telegraf:$$(stat -c '%g' /var/run/docker.sock)
volumes:
- ./telegraf/telegraf3.conf:/etc/telegraf/telegraf.conf
- /var/run/docker.sock:/var/run/docker.sock
I am getting this error:
Error response from daemon: unable to find group $(stat -c '%g' /var/run/docker.sock): no matching entries in group file
How can i fix this issue? :)
Background:
I'm trying to run Telegraf (https://github.com/influxdata/telegraf) with the docker input. I'm running Telegraf via Docker Compose, and i've configured it roughly like this:
telegraf3:
image: telegraf
volumes:
- ./telegraf/telegraf3.conf:/etc/telegraf/telegraf.conf
- /var/run/docker.sock:/var/run/docker.sock:rw
env_file:
- ./telegraf/telegraf.env
depends_on:
- influxdb
The telegraf configuration uses a docker input plugin to interact with the docker.sock. It doesn't work, i get a permission related error:
test-grafana-telegraf3-1 | 2022-12-29T12:09:10Z E! [inputs.docker] Error in plugin: Got permission denied while trying to connect to the Docker daemon socket at unix:///docker.sock: Get "http://%2Fdocker.sock/v1.24/info": dial unix /docker.sock: connect: permission denied
Basically, the entrypoint.sh script runs telegraf (the application) with the telegraf user, which can't access the docker.sock
There's a fix for this issue described here: Telegraf can not connect to Docker sock
Issue
As i am using docker compose, i would like this fix to be defined in the compose file, and not be dependent on me starting the container with docker run.
I've tried this:
telegraf3:
image: telegraf
volumes:
- ./telegraf/telegraf3.conf:/etc/telegraf/telegraf.conf
- /var/run/docker.sock:/var/run/docker.sock:rw
env_file:
- ./telegraf/telegraf.env
depends_on:
- influxdb
command: ["bash -c -u telegraf $$(stat -c '%g' /var/run/docker.sock)", "/entrypoint.sh"]
But then i get this error:
test-grafana-telegraf3-1 | setpriv: failed to execute bash -c -u telegraf $(stat -c '%g' /var/run/docker.sock): No such file or directory
test-grafana-telegraf3-1 exited with code 127