Kernel parameter allowing to pull firmware from separate path. Still has issue with file not being available in initramfs in Bazzite.

Build a tailored configuration:

mkdir -p ~/.config/samba
vi .config/samba/samba.json

In this file paste the following structure:

{
    "samba-container-config": "v0",
    "configs": {
        "config1": {
            "instance_name": "SAMBA",
            "instance_features": [],
            "shares": [
                "share1",
"share2"
            ],
            "globals": [
                "default"
            ]
        }
    },
    "shares": {
        "share1": {
            "options": {
                "path": "/share1",
                "valid users": "username"
            }
        },
        "share2": {
            "options": {
                "path": "/share2",
                "valid users": "username"
            },
            "permissions": {
                "method": "initialize-share-perms",
                "status_xattr": "user.share-perms-status",
                "mode": "0755"
            }
        }
    },
    "globals": {
        "default": {
            "options": {
                "security": "user",
                "server min protocol": "SMB2",
                "load printers": "no",
                "printing": "bsd",
                "printcap name": "/dev/null",
                "disable spoolss": "yes",
                "guest ok": "no"
            }
        }
    },
    "users": {
        "all_entries": [
            {
                "name": "username",
                "uid": 1000,
                "gid": 1000,
                "password": "password_cleartext"
            }
        ]
    },
    "groups": {
        "all_entries": [
            {
                "name": "usergroup",
                "gid": 1000
            }
        ]
    }
}

Make sure uid and gid match the uid and gid of the file owner on the host. If you have files with deviating ownership you might have change ownership before the service comes up otherwise it might fail.

Now create the corresponding podman quadlet:

mkdir -p ~/.config/containers/systemd/
vi ~/.config/containers/systemd/samba.container

Paste the following content:

 [Unit]
 Description=Podman samba.service
 Wants=network-online.target
 After=network-online.target
   
 [Service]
 Restart=on-failure
 TimeoutStartSec=900
   
 [Container]
 Image=quay.io/samba.org/samba-server:latest
 AutoUpdate=registry
 PublishPort=10445:445
 #UserNS=keep-id:uid=1000,gid=1000
 Environment=SAMBACC_CONFIG=/etc/samba-container/samba.json
 Environment=SAMBA_CONTAINER_ID=config1

 Volume=%h/.config/samba:/etc/samba-container:Z

 # Folders to share
 Volume=%h/path/to/share1:/share1:Z
 Volume=%h/path/to/share2:/share2:Z
   
 [Install]
 WantedBy=default.target



Now test the quadlet:

systemctl --user daemon-reload
systemctl --user start samba

If the container comes up as expected you need to forward the firewall from the priviledged low port to the unprivileged low port and open the samba port in the firewall:

firewall-cmd --add-service=samba --permanent
firewall-cmd --add-forward-port=port=445:proto=tcp:toport=10445 --permanent

This should be it.