fixed rootless docker setup

README.md

@@ -149,35 +149,72 @@ docker compose up --build -d       # rebuild after pulling code changes
 
 Anyone who can run `docker` commands effectively has root on the host (container volume mounts can reach the whole filesystem) — being in the `docker` group is root-equivalent. For a production server, it's worth confining this stack to a dedicated, unprivileged system user running its own **rootless Docker** daemon, instead of using a system-wide install or adding the user to the `docker` group.
 
-Rootless Docker runs as a completely independent daemon — separate socket (`/run/user/<uid>/docker.sock`) and storage (`~/.local/share/docker` vs. `/var/lib/docker`) — so it coexists fine with an existing system-wide Docker install on the same host. Just make sure `DOCKER_HOST`/`PATH` point at the rootless daemon when operating on this stack, and that the ports you publish in step 4 below aren't already in use elsewhere.
+Rootless Docker runs as a completely independent daemon — separate socket and storage (`~/.local/share/docker` vs. `/var/lib/docker`) — so it coexists fine with an existing system-wide Docker install on the same host. Just make sure `DOCKER_HOST`/`PATH` point at the rootless daemon when operating on this stack, and that the ports you publish in step 4 below aren't already in use elsewhere.
 
-**1. Create the user and enable lingering** (so its services keep running without an active login session):
+**1. Create the user:**
 
 ```sh
 sudo adduser --disabled-password --gecos "" rss-svc
-sudo loginctl enable-linger rss-svc
 ```
 
+> The "normal" rootless Docker setup runs the daemon as a **per-user systemd service** kept alive via `loginctl enable-linger`, which depends on `systemd-logind`/D-Bus. Minimal headless images (DietPi included) often disable or strip those out — and whether re-enabling them survives the distro's own update mechanism is genuinely unclear. Rather than depend on that, the steps below run rootless Docker as an ordinary **system-level** unit with `User=rss-svc` — no logind, no D-Bus, no lingering, nothing that can be reset out from under you.
+
 **2. Install rootless Docker for that user:**
 
 ```sh
-sudo apt install -y uidmap dbus-user-session
-sudo machinectl shell rss-svc@
-curl -fsSL https://get.docker.com/rootless | sh
+sudo apt install -y uidmap
+sudo -u rss-svc -H curl -fsSL https://get.docker.com/rootless -o /tmp/install-rootless.sh
+sudo -u rss-svc -H sh /tmp/install-rootless.sh
 ```
 
-Add to `~/.bashrc` (as `rss-svc`):
+Add to `~/.bashrc` (as `rss-svc` — e.g. `sudo -u rss-svc -H bash`):
 
 ```sh
 export PATH=/home/rss-svc/bin:$PATH
-export DOCKER_HOST=unix:///run/user/$(id -u)/docker.sock
+export XDG_RUNTIME_DIR=/run/rss-svc-docker
+export DOCKER_HOST=unix:///run/rss-svc-docker/docker.sock
 ```
 
-Enable the daemon as a persistent user service, then re-login (or `exec $SHELL`) so the exports above take effect:
+Now create the system unit at `/etc/systemd/system/docker-rss-svc.service`:
+
+```ini
+[Unit]
+Description=Rootless Docker daemon (rss-svc)
+After=network.target
+
+[Service]
+User=rss-svc
+Group=rss-svc
+Environment=PATH=/home/rss-svc/bin:/usr/bin:/bin
+Environment=XDG_RUNTIME_DIR=%t/rss-svc-docker
+RuntimeDirectory=rss-svc-docker
+RuntimeDirectoryMode=0700
+RuntimeDirectoryPreserve=yes
+ExecStart=/home/rss-svc/bin/dockerd-rootless.sh
+Restart=always
+RestartSec=2
+Delegate=yes
+Type=notify
+NotifyAccess=all
+KillMode=mixed
+TasksMax=infinity
+LimitNOFILE=1048576
+
+[Install]
+WantedBy=multi-user.target
+```
+
+`RuntimeDirectory=` makes systemd create `/run/rss-svc-docker` (owned by `rss-svc`, mode `0700`) on every boot — that's the `XDG_RUNTIME_DIR` rootless Docker needs, supplied without any session manager. Then enable and start it:
 
 ```sh
-systemctl --user enable docker
-systemctl --user start docker
+sudo systemctl daemon-reload
+sudo systemctl enable --now docker-rss-svc
+```
+
+Verify it came up (as `rss-svc`, with the `.bashrc` exports loaded):
+
+```sh
+docker info
 ```
 
 **3. Deploy the stack as `rss-svc`:**