1: I have been using subfolder of /mnt for different things when self-hosting. Different external drives go in different subfolders of /mnt. Example: Media drives are mounted at /mnt/media, data drives at /mnt/data etc.

2: I’m lazy. Mine are located in my server users home folder. I then use scripts to sync between them between desktop and server.

3: Just make sure than your server user, the docker user and root user can all read and maybe write to them.

I’d suggest /opt/docker/_compose/ for all the compose files. Or, if you keep all the config files for your containers on your NAS, maybe create a share there and put all yml files in it, then mount it on the host. This way everything is on your NAS and nothing is lost if the host freaks out.

And I’d add the NFS mounts to the compose files as well. When specifying volumes, you can use anything the host OS has a mount.xxx command for. Docker will take care of mounting everything.

I wouldn’t worry about mounting your nfs shares directly to those host unless you need to. Compose has an operator similar to k8s that lets docker itself manage the shares, which is insanely useful if you lose your host. Then you don’t have to have piles of scripts to mount them.

https://stackoverflow.com/questions/45282608/how-to-directly-mount-nfs-share-volume-in-container-using-docker-compose-v3

version: "3.2"

services:
  rsyslog:
    image: jumanjiman/rsyslog
    ports:
      - "514:514"
      - "514:514/udp"
    volumes:
      - type: volume
        source: example
        target: /nfs
        volume:
          nocopy: true
volumes:
  example:
    driver_opts:
      type: "nfs"
      o: "addr=10.40.0.199,nolock,soft,rw"
      device: ":/docker/example"

I have all external mounts in /mnt, if my container needs to use it then it’s in the compose file to use the local mount.

All my compose and stacks are in a git repo, the repo lives in my home dir and pulled fromy Gogs server. That only I can access.

In general, on bare-metal, I mount below /mnt. For a long time, I just mounted in from pre-setup host mounts. But, I use Kubernetes, and you can directly specify a NFS mount. So, I eventually migrated everything to that as I made other updates. I don’t think it’s horrible to mount from the host, but if docker-compose supports directly defining an NFS volume, that’s one less thing to set up if you need to re-provision your docker host.

(quick edit) I don’t think docker compose reads and re-reads compose files. They’re read when you invoke docker compose but that’s it. So…

If you’re simply invoking docker compose to interact with things, then I’d say store the compose files where ever makes the most sense for your process. Maybe think about setting up a specific directory on your NFS share and mount that to your docker host(s). I would also consider version controlling your compose files. If you’re concerned about secrets, store them in encrypted env files. Something like SOPS can help with this.

As long as the user invoking docker compose can read the compose files, you’re good. When it comes to mounting data into containers from NFS… yes permissions will matter and it might be a pain as it depends on how flexible the container you’re using is in terms of user and filesystem permissions.

One thing to consider with NFS is how stable your network is.

I’ve moved away from storing application files on my NAS and instead I store them locally where I run the application.

For things like jellyfin media or paperless files they can stay on the NAS and be accessed via NFS, but the config, db and other files the apps create as part of their operation, things can get into a bad state if the network drops at an unexpected time.

Instead I setup backup cronjobs that backup those files to the NAS nightly.

I agree with the other commenters regarding using the NFS share mounting right in docker compose. It does work great once you get it working.