doc: better doc on systemd's DynamicUser (fix #430)

This commit is contained in:
Alex Auvolat 2023-06-14 12:33:25 +02:00
parent 39c3738a07
commit 120f8b3bfb

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@ -33,7 +33,20 @@ NoNewPrivileges=true
WantedBy=multi-user.target
```
*A note on hardening: garage will be run as a non privileged user, its user id is dynamically allocated by systemd. It cannot access (read or write) home folders (/home, /root and /run/user), the rest of the filesystem can only be read but not written, only the path seen as /var/lib/garage is writable as seen by the service (mapped to /var/lib/private/garage on your host). Additionnaly, the process can not gain new privileges over time.*
**A note on hardening:** Garage will be run as a non privileged user, its user
id is dynamically allocated by systemd (set with `DynamicUser=true`). It cannot
access (read or write) home folders (`/home`, `/root` and `/run/user`), the
rest of the filesystem can only be read but not written, only the path seen as
`/var/lib/garage` is writable as seen by the service. Additionnaly, the process
can not gain new privileges over time.
For this to work correctly, your `garage.toml` must be set with
`metadata_dir=/var/lib/garage/meta` and `data_dir=/var/lib/garage/data`. This
is mandatory to use the DynamicUser hardening feature of systemd, which
autocreates these directories as virtual mapping. If the directory
`/var/lib/garage` already exists before starting the server for the first time,
the systemd service might not start correctly. Note that in your host
filesystem, Garage data will be held in `/var/lib/private/garage`.
To start the service then automatically enable it at boot: