mirror of
https://github.com/systemd/systemd-stable.git
synced 2024-12-25 23:21:33 +03:00
c28904dae0
The old version of this command will delete everything under the new home directory (including `.identity`), rendering the directory unusable with homed.
136 lines
6.0 KiB
Markdown
136 lines
6.0 KiB
Markdown
---
|
|
title: Converting Existing Users to systemd-homed
|
|
category: Users, Groups and Home Directories
|
|
layout: default
|
|
---
|
|
|
|
# Converting Existing Users to systemd-homed managed Users
|
|
|
|
Traditionally on most Linux distributions, regular (human) users are managed
|
|
via entries in `/etc/passwd`, `/etc/shadow`, `/etc/group` and
|
|
`/etc/gshadow`. With the advent of
|
|
[`systemd-homed`](https://www.freedesktop.org/software/systemd/man/systemd-homed.service.html)
|
|
it might be desirable to convert an existing, traditional user account to a
|
|
`systemd-homed` managed one. Below is a brief guide how to do that.
|
|
|
|
Before continuing, please read up on these basic concepts:
|
|
|
|
* [Home Directories](https://systemd.io/HOME_DIRECTORY)
|
|
* [JSON User Records](https://systemd.io/USER_RECORD)
|
|
* [JSON Group Records](https://systemd.io/GROUP_RECORD)
|
|
* [User/Group Record Lookup API via Varlink](https://systemd.io/USER_GROUP_API)
|
|
|
|
## Caveat
|
|
|
|
This is a manual process, and possibly a bit fragile. Hence, do this at your
|
|
own risk, read up beforehand, and make a backup first. You know what's at
|
|
stake: your own home directory, i.e. all your personal data.
|
|
|
|
## Step-By-Step
|
|
|
|
Here's the step-by-step guide:
|
|
|
|
0. Preparations: make sure you run a distribution that has `systemd-homed`
|
|
enabled and properly set up, including the necessary PAM and NSS
|
|
configuration updates. Make sure you have enough disk space in `/home/` for
|
|
a (temporary) second copy of your home directory. Make sure to backup your
|
|
home directory. Make sure to log out of your user account fully. Then log in
|
|
as root on the console.
|
|
|
|
1. Rename your existing home directory to something safe. Let's say your user
|
|
ID is `foobar`. Then do:
|
|
|
|
```
|
|
mv /home/foobar /home/foobar.saved
|
|
```
|
|
|
|
2. Have a look at your existing user record, as stored in `/etc/passwd` and
|
|
related files. We want to use the same data for the new record, hence it's good
|
|
looking at the old data. Use commands such as:
|
|
|
|
```
|
|
getent passwd foobar
|
|
getent shadow foobar
|
|
```
|
|
|
|
This will tell you the `/etc/passwd` and `/etc/shadow` entries for your
|
|
user. For details about the fields, see the respective man pages
|
|
[passwd(5)](http://man7.org/linux/man-pages/man5/passwd.5.html) and
|
|
[shadow(5)](http://man7.org/linux/man-pages/man5/shadow.5.html).
|
|
|
|
The fourth field in the `getent passwd foobar` output tells you the GID of
|
|
your user's main group. Depending on your distribution it's a group private
|
|
to the user, or a group shared by most local, regular users. Let's say the
|
|
GID reported is 1000, let's then query its details:
|
|
|
|
```
|
|
getent group 1000
|
|
```
|
|
|
|
This will tell you the name of that group. If the name is the same as your
|
|
user name your distribution apparently provided you with a private group for
|
|
your user. If it doesn't match (and is something like `users`) it apparently
|
|
didn't. Note that `systemd-homed` will always manage a private group for
|
|
each user under the same name, hence if your distribution is one of the
|
|
latter kind, then there's a (minor) mismatch in structure when converting.
|
|
|
|
Save the information reported by these three commands somewhere, for later
|
|
reference.
|
|
|
|
3. Now edit your `/etc/passwd` file and remove your existing record
|
|
(i.e. delete a single line, the one of your user's account, leaving all
|
|
other lines unmodified). Similar for `/etc/shadow`, `/etc/group` (in case
|
|
you have a private group for your user) and `/etc/gshadow`. Most
|
|
distributions provide you with a tool for that, that adds safe
|
|
synchronization for these changes: `vipw`, `vipw -s`, `vigr` and `vigr -s`.
|
|
|
|
4. At this point the old user account vanished, while the home directory still
|
|
exists safely under the `/home/foobar.saved` name. Let's now create a new
|
|
account with `systemd-homed`, using the same username and UID as before:
|
|
|
|
```
|
|
homectl create foobar --uid=$UID --real-name=$GECOS
|
|
```
|
|
|
|
In this command line, replace `$UID` by the UID you previously used,
|
|
i.e. the third field of the `getent passwd foobar` output above. Similar,
|
|
replace `$GECOS` by the GECOS field of your old account, i.e the fifth field
|
|
of the old output. If your distribution traditionally does not assign a
|
|
private group to regular user groups, then consider adding `--member-of=`
|
|
with the group name to get a modicum of compatibility with the status quo
|
|
ante: this way your new user account will still not have the old primary
|
|
group as new primary group, but will have it as auxiliary group.
|
|
|
|
Consider reading through the
|
|
[homectl(1)](https://www.freedesktop.org/software/systemd/man/homectl.html)
|
|
manual page at this point, maybe there are a couple of other settings you
|
|
want to set for your new account. In particular, look at `--storage=` and
|
|
`--disk-size=`, in order to change how your home directory shall be stored
|
|
(the default `luks` storage is recommended).
|
|
|
|
5. Your new user account exists now, but it has an empty home directory. Let's
|
|
now migrate your old home directory into it. For that let's mount the new
|
|
home directory temporarily and copy the data in.
|
|
|
|
```
|
|
homectl with foobar -- rsync -aHAXv --remove-source-files /home/foobar.saved/ .
|
|
```
|
|
|
|
This mounts the home directory of the user, and then runs the specified
|
|
`rsync` command which copies the contents of the old home directory into the
|
|
new. The new home directory is the working directory of the invoked `rsync`
|
|
process. We are invoking this command as root, hence the `rsync` runs as
|
|
root too. When the `rsync` command completes the home directory is
|
|
automatically unmounted again. Since we used `--remove-source-files` all files
|
|
copied are removed from the old home directory as the copy progresses. After
|
|
the command completes the old home directory should be empty. Let's remove
|
|
it hence:
|
|
|
|
```
|
|
rmdir /home/foobar.saved
|
|
```
|
|
|
|
And that's it, we are done already. You can log out now and should be able to
|
|
log in under your user account as usual, but now with `systemd-homed` managing
|
|
your home directory.
|