I can execute a `docker run` command as such ... 

```
docker run --rm  --user $(id -u):$(id -g) -e MYDATA=/some/path/to/data -e USER=$USER -p 8883-8887:8883-8887 ...

```

However, in Docker Compose, when I write out the following ... 

```
version: '3.7'
services:
  container_name: some-server
  image: some:img
  user: $(id -u):$(id -g) 
  ... 

```

... it does not work. 

I understand I am asking `docker-compose up` to perform sub shell command substitution, and it cannot. 

Is there any way to do this?