/etc/resolv.conf missing on live CD

Bug #1045757 reported by BlueLight
This bug affects 2 people
Affects Status Importance Assigned to Milestone
In Progress

Bug Description

When creating an ISO of a working 12.04 Ubuntu system ISO doesn't copy the /etc/resolv.conf link created on the original OS by resolvconf package - which breaks networking (DNS).
That makes the resulting live ISO not very "live" - browsing and all DNS dependent stuff just fails.
I've also tried remastersys - same story.
Ugly workaround: after booting live iso or after installing a system from it I have to run "sudo dpkg-reconfigure resolvconf " and answer "ok-yes"... and then it's all good.

There is a related bug repoer with Ubuntu team: https://bugs.launchpad.net/ubuntu/+source/resolvconf/+bug/1000244
and it looks like someone was running into the same issue with Debian's custom ISO and they solved it:

Revision history for this message
mpc (mpcottam) wrote :

I found the same problem. I have a workaround which is slightly less ugly - it doesn't require using dpkg-reconfigure interface.

Any files placed in the /etc/skel directory are transferred to the live users home directory when the live system starts

So if you do the following in the original system:

sudo pico /etc/skel/netfixer.sh

and then add these two lines to the file:

echo 'nameserver' > /etc/resolv.conf
/etc/init.d/networking restart

then save

change permissions of the file:

sudo chmod 777 /etc/skel/netfixer.sh

When the custom.iso is built you will have netfixer.sh in the home folder of the live user when booting

In the live system from the terminal:

sudo ./netfixer.sh

will restore network functionality.

It just gets the above fix down to a single console line with no interaction required. Takes about 4 seconds to run.


Revision history for this message
Anonymous Meerkat (lkjoel) wrote :

@BlueLight "When creating an ISO of a working 12.04 Ubuntu system ISO doesn't copy the /etc/resolv.conf link created on the original OS by resolvconf package - which breaks networking (DNS)." <- Correct, relinux excludes this as using someone else's internet connection will not always work anther users system. What is weird is that casper should have generated this before loading the computer.

@mpc Hmm, seems a bit hacky (static nameserver?).

Will look into this issue and try to replicate it. This is actually an issue with casper, so once a fix is found, it will be uploaded there (might add some sed/awk hacks to relinux for people using older versions of it).

Sorry about my late reply on this issue, and thanks for the bug report and workarounds.

Changed in relinux:
importance: Undecided → High
status: New → Triaged
Revision history for this message
Per (perguth) wrote :

I run into this problem using a customized 14.04.2 LiveCD using Customizer[1].

[1]: https://github.com/clearkimura/Customizer

Revision history for this message
kokoye2007  (kokoye2007) wrote :

sudo gedit /usr/bin/remastersys


Remove only



Changed in relinux:
status: Triaged → In Progress
assignee: nobody → kokoye2007 (kokoye2007)
Revision history for this message
Anonymous Meerkat (lkjoel) wrote :

For relinux 0.3a3, try replacing (line 638):

rm -rf X11/xorg.conf* resolv.conf hosts hostname timezone {m,fs}tab


rm -rf X11/xorg.conf* hosts hostname timezone {m,fs}tab

to keep resolv.conf.

Ubuntu seems to have changed since the script was released, and /etc/resolv.conf is now a link that points to /run/resolvconf/resolv.conf. Because of this, casper will not create /etc/resolv.conf if it doesn't exist, and will only update /run/resolvconf/resolv.conf.

However, casper will only update /run/resolvconf/resolv.conf if it's empty, so try adding:

emptyfile /run/resolvconf/resolv.conf

somewhere after the first replaced line. Ubuntu might try to replace the contents of this file before relinux has a chance to compress this in filesystem.squashfs, so I would advise you to disconnect your internet before running relinux.

This is not a good fix in any way, because it modifies the filesystem of your host computer (other than in /home/relinux), which was a strict non-goal of relinux. However, I'm hoping it should work, at least temporarily :)

If it doesn't work, try replacing the emptyfile line with:

cat << EOF > /run/resolvconf/resolv.conf

I'm very sorry, I had entirely forgotten about this bug report. Let me know if this works! :)

A better fix would be to copy /run to dummysys, and modify run/resolvconf/resolv.conf there, then add it to stage 1 of filesystem.squashfs (and exclude it from stage 2). This will probably be what I will do for relinux (if this works).

Changed in relinux:
assignee: kokoye2007  (kokoye2007) → Aung Khant Zaw (railgunx)
assignee: Aung Khant Zaw (railgunx) → nobody
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