Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Felipe Sateler]

On Thu, Apr 4, 2019 at 7:15 AM Michael Biebl  wrote:

> Am 03.04.19 um 20:34 schrieb Felipe Sateler:
> > On Wed, Apr 3, 2019 at 1:23 PM Michael Biebl  > > wrote:
>
> > I have no idea how common that is, so maybe an alternative could be
> to
> > move the libpam-systemd Recommends from systemd to systemd-sysv
> > (alongside the existing libnss-systemd).
> >
> >
> > Makes a lot of sense to me.
> >
> >
> > WDYT? Is it too late in the release cycle to make such a change?
> >
> >
> > I don't know. Most likely we would need a tight dependency on systemd,
> > to ensure at least one pacakge Recommends libpam-systemd.
>
> If we want to ensure that, we'd have to add a versioned systemd-sysv
> dependency to systemd (or a versioned Breaks for that matter). Both are
> problematic.
> But I might be misunderstanding what you have in mind here.
>

That's precisely what I meant.  Otherwise you might end up with old
systemd-sysv + new systemd => nothing depends on libpam-systemd.

Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Michael Biebl]

Am 03.04.19 um 20:34 schrieb Felipe Sateler:
> On Wed, Apr 3, 2019 at 1:23 PM Michael Biebl  > wrote:

> I have no idea how common that is, so maybe an alternative could be to
> move the libpam-systemd Recommends from systemd to systemd-sysv
> (alongside the existing libnss-systemd).
> 
> 
> Makes a lot of sense to me.
>  
> 
> WDYT? Is it too late in the release cycle to make such a change?
> 
> 
> I don't know. Most likely we would need a tight dependency on systemd,
> to ensure at least one pacakge Recommends libpam-systemd.

If we want to ensure that, we'd have to add a versioned systemd-sysv
dependency to systemd (or a versioned Breaks for that matter). Both are
problematic.
But I might be misunderstanding what you have in mind here.

-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?



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Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Felipe Sateler]

On Wed, Apr 3, 2019 at 1:23 PM Michael Biebl  wrote:

> Am 03.04.19 um 18:08 schrieb Felipe Sateler:
> > Looks like sysvinit-core needs XB-Important: yes to prevent such easy
> > removal.
>
> I though about this too, but on the other hand with "init" we actually
> allow users to switch between sysvinit and systemd and adding
> XB-Important: yes to sysvinit-core would render "init" moot.
>

Ah, you are right. I mixed init with systemd-sysv, which does not have the
Important flag set.


>
> I have to say I'm surprised apt prefers uninstalling a package to
> satisfy a Recommends over not installing a Recommends and keeping that
> package.
>

Yeah, I that is surprising. Would it make sense to loop the apt maintainers
into this?


>
>
> If systemd is the active PID 1, we want libpam-systemd installed
> alongside. So far we also considered that users might not have
> systemd-sysv installed but instead boot with init=/lib/systemd/systemd.
> I have no idea how common that is, so maybe an alternative could be to
> move the libpam-systemd Recommends from systemd to systemd-sysv
> (alongside the existing libnss-systemd).
>

Makes a lot of sense to me.


> WDYT? Is it too late in the release cycle to make such a change?
>

I don't know. Most likely we would need a tight dependency on systemd, to
ensure at least one pacakge Recommends libpam-systemd.

-- 

Saludos,
Felipe Sateler

Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Michael Biebl]

Am 03.04.19 um 18:08 schrieb Felipe Sateler:
> Looks like sysvinit-core needs XB-Important: yes to prevent such easy
> removal.

I though about this too, but on the other hand with "init" we actually
allow users to switch between sysvinit and systemd and adding
XB-Important: yes to sysvinit-core would render "init" moot.

I have to say I'm surprised apt prefers uninstalling a package to
satisfy a Recommends over not installing a Recommends and keeping that
package.


If systemd is the active PID 1, we want libpam-systemd installed
alongside. So far we also considered that users might not have
systemd-sysv installed but instead boot with init=/lib/systemd/systemd.
I have no idea how common that is, so maybe an alternative could be to
move the libpam-systemd Recommends from systemd to systemd-sysv
(alongside the existing libnss-systemd).


WDYT? Is it too late in the release cycle to make such a change?

Michael
-- 
Why is it that all of the instruments seeking intelligent life in the
universe are pointed away from Earth?



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Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Felipe Sateler]

On Wed, Apr 3, 2019 at 7:18 AM Emmanuel Bourg  wrote:

> Package: systemd
> Version: 241-1
> Severity: normal
>
> Hi,
>
> The description of the systemd package states that installing it will not
> switch the init system, unfortunately that's what happens, unless systemd
> is installed with --no-install-recommends. It looks like a recommended
> dependency (libpam-systemd?) triggers the removal of sysvinit-core.


> I haven't been able to track exactly why it happens in testing with the
> version 241-1. With the version 241-2 in sid I guess the removal of
> systemd-shim from the alternative dependencies of libpam-systemd [1]
> last week doesn't help.
>
>
> root@sysvinit:~# ps aux
> USER   PID %CPU %MEMVSZ   RSS TTY  STAT START   TIME
> COMMAND
> root 1  0.0  0.0   7900  1980 pts/1Ss+  09:29   0:00 init
> [2]
> root   884  0.0  0.1 156188  2412 ?Ssl  09:29   0:00
> /usr/sbin/rsyslogd
> root   912  0.0  0.0   5508  1968 ?Ss   09:29   0:00
> /usr/sbin/cron
> root   940  0.0  0.1   4000  3300 ?Ss   09:29   0:00
> /bin/bash
> root  1237  0.0  0.0   2420  1480 pts/0Ss+  09:31   0:00
> /sbin/getty --noclear 38400 tty1
> root  1238  0.0  0.0   2420  1556 pts/1Ss+  09:31   0:00
> /sbin/getty --noclear 38400 tty2
> root  2269  0.0  0.1   7640  2724 ?R+   09:53   0:00 ps aux
>
> root@sysvinit:~# ls -l /sbin/init
> -rwxr-xr-x 1 root root 53016 Feb 14 20:33 /sbin/init
>
> root@sysvinit:~# apt install systemd
> Reading package lists... Done
> Building dependency tree
> Reading state information... Done
> The following packages were automatically installed and are no longer
> required:
>   initscripts insserv startpar sysv-rc
> Use 'apt autoremove' to remove them.
> The following additional packages will be installed:
>   dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3
> libnss-systemd libpam-systemd systemd-sysv
> Suggested packages:
>   default-dbus-session-bus | dbus-session-bus systemd-container
> policykit-1
> The following packages will be REMOVED:
>   sysvinit-core
> The following NEW packages will be installed:
>   dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3
> libnss-systemd libpam-systemd systemd systemd-sysv
> 0 upgraded, 10 newly installed, 1 to remove and 0 not upgraded.
> Need to get 4786 kB of archives.
> After this operation, 16.7 MB of additional disk space will be used.
> Do you want to continue? [Y/n] n
> Abort.
>

Looks like sysvinit-core needs XB-Important: yes to prevent such easy
removal.

-- 

Saludos,
Felipe Sateler

Bug#926316: systemd: Installing the systemd package switches the init system to systemd

[Emmanuel Bourg]

Package: systemd
Version: 241-1
Severity: normal

Hi,

The description of the systemd package states that installing it will not
switch the init system, unfortunately that's what happens, unless systemd
is installed with --no-install-recommends. It looks like a recommended
dependency (libpam-systemd?) triggers the removal of sysvinit-core.

I haven't been able to track exactly why it happens in testing with the
version 241-1. With the version 241-2 in sid I guess the removal of
systemd-shim from the alternative dependencies of libpam-systemd [1]
last week doesn't help.


root@sysvinit:~# ps aux
USER   PID %CPU %MEMVSZ   RSS TTY  STAT START   TIME COMMAND
root 1  0.0  0.0   7900  1980 pts/1Ss+  09:29   0:00 init [2]
root   884  0.0  0.1 156188  2412 ?Ssl  09:29   0:00 
/usr/sbin/rsyslogd
root   912  0.0  0.0   5508  1968 ?Ss   09:29   0:00 
/usr/sbin/cron
root   940  0.0  0.1   4000  3300 ?Ss   09:29   0:00 /bin/bash
root  1237  0.0  0.0   2420  1480 pts/0Ss+  09:31   0:00 
/sbin/getty --noclear 38400 tty1
root  1238  0.0  0.0   2420  1556 pts/1Ss+  09:31   0:00 
/sbin/getty --noclear 38400 tty2
root  2269  0.0  0.1   7640  2724 ?R+   09:53   0:00 ps aux

root@sysvinit:~# ls -l /sbin/init
-rwxr-xr-x 1 root root 53016 Feb 14 20:33 /sbin/init

root@sysvinit:~# apt install systemd
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages were automatically installed and are no longer 
required:
  initscripts insserv startpar sysv-rc
Use 'apt autoremove' to remove them.
The following additional packages will be installed:
  dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3 
libnss-systemd libpam-systemd systemd-sysv
Suggested packages:
  default-dbus-session-bus | dbus-session-bus systemd-container policykit-1
The following packages will be REMOVED:
  sysvinit-core
The following NEW packages will be installed:
  dbus libargon2-1 libcryptsetup12 libdbus-1-3 libexpat1 libjson-c3 
libnss-systemd libpam-systemd systemd systemd-sysv
0 upgraded, 10 newly installed, 1 to remove and 0 not upgraded.
Need to get 4786 kB of archives.
After this operation, 16.7 MB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

root@sysvinit:~# apt install systemd --no-install-recommends
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following additional packages will be installed:
  libargon2-1 libcryptsetup12 libjson-c3
Suggested packages:
  systemd-container policykit-1
Recommended packages:
  libpam-systemd dbus
The following NEW packages will be installed:
  libargon2-1 libcryptsetup12 libjson-c3 systemd
0 upgraded, 4 newly installed, 0 to remove and 0 not upgraded.
Need to get 3733 kB of archives.
After this operation, 14.4 MB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

Emmanuel Bourg

[1] https://salsa.debian.org/systemd-team/systemd/commit/8d292a0a