[Bug 1782275] [NEW] Conflict between resolvconf and systemd-resolved dhclient scripts

[Daniel Richard G.]

Public bug reported:

I am setting up an Ubuntu 18.04 (bionic) system with ifupdown instead of
netplan, as the latter does not meet my needs. I am using resolvconf to
update /etc/resolv.conf from DHCP, as in earlier releases.

Unfortunately, I am not seeing /etc/resolv.conf (actually a symlink to
/run/resolvconf/resolv.conf) being updated; it is only the boilerplate
from /etc/resolvconf/resolv.conf.d/head with no server information
appended. (My "base" and "tail" files are empty.)

I poked around the scripts in /etc, and believe I have found the
problem.

When resolvconf is installed, the following two files are present:

    /etc/dhcp/dhclient-enter-hooks.d/resolvconf
    /etc/dhcp/dhclient-enter-hooks.d/resolved

Both of these scripts define the make_resolv_conf() shell function. What
I am seeing is that dhclient runs these two scripts in the
(alphabetical) order shown, and as the resolved script runs second, it
overwrites the resolvconf version of the shell function with its own. As
a result, dhclient does not invoke the appropriate update command for
resolvconf, even though the hook script was installed correctly.

Normally, I would remove the package that is providing the "resolved"
script, but this package is systemd, which cannot be removed. I am not
sure which of the two packages (resolvconf or systemd) needs to make an
accommodation for the other, but it is clear that the current approach
does not work.

** Affects: resolvconf (Ubuntu)
     Importance: Undecided
         Status: New

** Affects: systemd (Ubuntu)
     Importance: Undecided
         Status: New

** Also affects: systemd (Ubuntu)
   Importance: Undecided
       Status: New

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to resolvconf in Ubuntu.
https://bugs.launchpad.net/bugs/1782275

Title:
  Conflict between resolvconf and systemd-resolved dhclient scripts

Status in resolvconf package in Ubuntu:
  New
Status in systemd package in Ubuntu:
  New

Bug description:
  I am setting up an Ubuntu 18.04 (bionic) system with ifupdown instead
  of netplan, as the latter does not meet my needs. I am using
  resolvconf to update /etc/resolv.conf from DHCP, as in earlier
  releases.

  Unfortunately, I am not seeing /etc/resolv.conf (actually a symlink to
  /run/resolvconf/resolv.conf) being updated; it is only the boilerplate
  from /etc/resolvconf/resolv.conf.d/head with no server information
  appended. (My "base" and "tail" files are empty.)

  I poked around the scripts in /etc, and believe I have found the
  problem.

  When resolvconf is installed, the following two files are present:

      /etc/dhcp/dhclient-enter-hooks.d/resolvconf
      /etc/dhcp/dhclient-enter-hooks.d/resolved

  Both of these scripts define the make_resolv_conf() shell function.
  What I am seeing is that dhclient runs these two scripts in the
  (alphabetical) order shown, and as the resolved script runs second, it
  overwrites the resolvconf version of the shell function with its own.
  As a result, dhclient does not invoke the appropriate update command
  for resolvconf, even though the hook script was installed correctly.

  Normally, I would remove the package that is providing the "resolved"
  script, but this package is systemd, which cannot be removed. I am not
  sure which of the two packages (resolvconf or systemd) needs to make
  an accommodation for the other, but it is clear that the current
  approach does not work.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1782275/+subscriptions