[SRU] Not looking for library in multiarch-friendly path

[Gerben]

SRU Request for Precise

##### SRU Justification #####

[Impact]
Site-forwarding is not possible,
Precise cannot be used as a forwarding host to link to sites hosted within a private network.

[Development Fix]
I added the sed command mentioned below into the debian/postinst script so that the path is corrected at installation. Editing the file (debian/conf/proxy_html.load) itself won't be of any use because the path differs by architecture.

[Stable Fix]
Edit the file /etc/apache2/mods-enabled/proxy_html.load to include the right path using the following sed command:

sed -i "s/\/usr\/lib\/libxml2.so.2/\/usr\/lib\/`uname -i`-linux-gnu\/libxml2.so.2/g" /etc/apache2/mods-available/proxy_html.load

[Test Case]
1) Install the packages 'apache2', 'libxml2', and 'libapache2-mod-proxy-html'
2) Run the command 'sudo service apache2 start'

With the version in Precise, it will error out with:
apache2: Syntax error on line 210 of /etc/apache2/apache2.conf: Syntax error on line 1 of /etc/apache2/mods-enabled/proxy_html.load: Cannot load /usr/lib/libxml2.so.2 into server: /usr/lib/libxml2.so.2: cannot open shared object file: No such file or directory
Action 'start' failed.

[Regression Potential]
Little, as Apache doesn't run currently anyway

libxml2 2.7.8.dfsg-5.1ubuntu4.1 running on Ubuntu 12.04 LTS

------------ORIGINAL REPORT------------

See also package libapache2-mod-proxy-html , file/link /etc/apache2/mods-enabled/proxy_html.load

# lsb_release -rd
Description: Ubuntu 12.04 LTS
Release: 12.04

(64 bit)

# apt-cache policy libxml2
libxml2:
  Installed: 2.7.8.dfsg-5.1ubuntu4.1
  Candidate: 2.7.8.dfsg-5.1ubuntu4.1
  Version table:
 *** 2.7.8.dfsg-5.1ubuntu4.1 0
        500 http://de.archive.ubuntu.com/ubuntu/ precise-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ precise-security/main amd64 Packages
        100 /var/lib/dpkg/status
     2.7.8.dfsg-5.1ubuntu4 0
        500 http://de.archive.ubuntu.com/ubuntu/ precise/main amd64 Packages

# apt-cache policy libapache2-mod-proxy-html:
libapache2-mod-proxy-html:
  Installed: 3.0.1-1
  Candidate: 3.0.1-1
  Version table:
 *** 3.0.1-1 0
        500 http://de.archive.ubuntu.com/ubuntu/ precise/universe amd64 Packages
        100 /var/lib/dpkg/status

Expected:
I expected apache to start including module proxy_html.load.

What happened:
apache2 failed to start and showed an error message
# service apache2 start
 * Starting web server apache2 apache2: Syntax error on line 210 of /etc/apache2/apache2.conf: Syntax error on line 1 of /etc/apache2/mods-enabled/proxy_html.load: Cannot load /usr/lib/libxml2.so.2 into server: /usr/lib/libxml2.so.2: cannot open shared object file: No such file or directory
Action 'start' failed.
The Apache error log may have more information.
                                                                                           [fail]

proxy_html.load tries to load libxml2 (LoadFile /usr/lib/libxml2.so.2), but libxml2 only provides under /usr/lib/x86_64-linux-gnu
(under 10.04 64 bit things are available under /usr/lib)

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: libxml2 2.7.8.dfsg-5.1ubuntu4.1
ProcVersionSignature: Ubuntu 3.2.0-24.39-generic 3.2.16
Uname: Linux 3.2.0-24-generic x86_64
ApportVersion: 2.0.1-0ubuntu7
Architecture: amd64
Date: Mon May 28 09:25:26 2012
InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1)
ProcEnviron:
 LANGUAGE=en_US:en
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: libxml2
UpgradeStatus: No upgrade log present (probably fresh install)

[Aditya V (kroq-gar78)]

Seems like libxml2.so.2 is in the folder "/usr/lib/x86_64-linux-gnu/" on my 64-bit Precise. Are you using a 32-bit or 64-bit machine to produce this bug?

[Gerben (gerbgeus)]

I've noticed this on a 64 bit installation, but 32 bit also lacks these files under /usr/lib

(from 32 bit:
$ dpkg -L libxml2
/.
/usr
/usr/lib
/usr/lib/i386-linux-gnu
/usr/lib/i386-linux-gnu/libxml2.so.2.7.8
/usr/share
/usr/share/doc
/usr/share/doc/libxml2
/usr/share/doc/libxml2/AUTHORS
/usr/share/doc/libxml2/README
/usr/share/doc/libxml2/README.Debian
/usr/share/doc/libxml2/copyright
/usr/share/doc/libxml2/TODO.gz
/usr/share/doc/libxml2/NEWS.gz
/usr/share/doc/libxml2/changelog.Debian.gz
/usr/lib/i386-linux-gnu/libxml2.so.2
geus@b32s1204:~$ cd /usr/lib/
geus@b32s1204:/usr/lib$ ls | grep libxml
geus@b32s1204:/usr/lib$
)

[Aditya V (kroq-gar78)]

I'll take care on this one. Can't set the assignee to me right now as I'm on my phone and it concerts the emails to HTML so I can't use LaunchPad's email interface.

Sincerely,
kroq-gar78

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Aditya V (kroq-gar78)]

Looks like it's a problem with the file "debian/conf/proxy_html.load". It has the contents:

LoadFile /usr/lib/libxml2.so.2
LoadModule proxy_html_module /usr/lib/apache2/modules/mod_proxy_html.so

The important part being of the first line: "/usr/lib/libxml2.so.2". Looks like that needs to be customized in some manner, either through debian/rules or some post-install script (post-install sounds better to me). Also, thanks Aron for pointing me in the right direction! :)

[Aditya V (kroq-gar78)]

Here's the patch. What I did was I replaced the path in the debian/conf/proxy_html.load file in the 'postinst' script. I did this using sed and I made sure it was using the correct architecture path (which is why I didn't put it into the proxy_html.load file directly)

[Aditya V (kroq-gar78)]

Here's the patch without a silly typo.

[Aditya V (kroq-gar78)]

Hmmm... just remembered that dpkg-architecture is part of dpkg-dev, and I don't want to add another dependency in. I'll use 'uname -m' and then append '-linux-gnu' to that. Please tell me if anybody has an alternative solution.

[Aditya V (kroq-gar78)]

Gerben,

Can you post the output of "uname -m" on your 32-bit machine? I'm just trying to make sure that that's an alternative to using "dpkg-architecture"

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "Fix path to use multiarch-friendly in 'postinst' script (no typo)" of this bug report has been identified as being a patch. The ubuntu-reviewers team has been subscribed to the bug report so that they can review the patch. In the event that this is in fact not a patch you can resolve this situation by removing the tag 'patch' from the bug report and editing the attachment so that it is not flagged as a patch. Additionally, if you are member of the ubuntu-reviewers team please also unsubscribe the team from this bug report.

[This is an automated message performed by a Launchpad user owned by Brian Murray. Please contact him regarding any issues with the action taken in this bug report.]

[Gerben (gerbgeus)]

Hi,

geus@b32s1204:~$ uname -m
i686

(image ubuntu-12.04-server-i386.iso used to install inside kvm hypervisor)
Gerben

[Aditya V (kroq-gar78)]

Hmm... not what I had hoped for. I'm trying to get a command to output 'i386' from your machine and 'x86_64' from mine (64-bit). Can you try running the command "arch" on your 32-bit system? Thanks. There's got to be a better way to do this...

[Gerben (gerbgeus)]

Hi,

The command to use is
  uname -i

This produced your excepted strings on the different platforms.

I've quickly looked at other apache modules, and mod_serurity also has the same problem.

[Aditya V (kroq-gar78)]

Thanks! I'll update my patch and branch. :)

I think I (or you, if you want) should file a separate bug report for mod_security, unless it's already been reported.

[Aditya V (kroq-gar78)]

Maybe this should be done through debian/rules instead of debian/postinst?

[Aditya V (kroq-gar78)]

Good patch (that works)

[Aditya V (kroq-gar78)]

Gerben,

Can you fill out the Impact field? Basically, what is the impact of the problem? Thanks! Once you do that, I'll request a merge.

[Aditya V (kroq-gar78)]

Also, can you test this fix by running

sed -i "s/\/usr\/lib\/libxml2.so.2/\/usr\/lib\/`uname -i`-linux-gnu\/libxml2.so.2/g" /etc/apache2/mods-available/proxy_html.load

in a terminal and seeing if it solves the problem? Thanks.

[Gerben (gerbgeus)]

IMPACT:
LOW-MEDIUM
Site-forwarding is not possible,
  - 12.04 cannot be used as a forwarding host to link to sites hosted within a private network.
  (just keep using previous ubuntu version for the moment)

[Aditya V (kroq-gar78)]

Ok, added the impact. As soon as you test the fix, I'll set my branch to merge and they'll hopefully have it uploaded in a little while. Can you please test the command I wrote eariler? Thanks.

[Gerben (gerbgeus)]

Hi,

ran the sed command and apache starts with the module enabled (both 64 and 32 bit installations).
This issue seems to be resolved.

[Andrew Starr-Bochicchio (andrewsomething)]

Can anyone confirm if this is still an issue in Quantal? Version 3.0.1-1.1 which was synced from Debian should have fixed this.

mod-proxy-html (3.0.1-1.1) unstable; urgency=medium

   * Non-maintainer upload.
   * Modify the path of libxml2.so.2 in conf file, update the minmal
     version of apache2 (Closes: #670633).
   * debian/compat: 4 -> 9.
   * debian/rules:
     - Replace dh_clean -k with dh_prep.
     - Add build-arch and build-indep target.
   * debian/dirs: removed, useless.
   * debian/source/format: 3.0 (quilt)
   * std-ver: 3.8.0 -> 3.9.3
 -- Aron Xu <email address hidden> Wed, 30 May 2012 08:59:37 +0000

[Gerben (gerbgeus)]

Hi,

Performed the test in quantal-server-amd64.iso and this is no issue in Quantal. The LoadFile directive looks nice without any absolute path, probably using some LD_LIBPATH or LIBRARY_PATH in the background.

root@b64s1210:/etc/apache2/mods-enabled# dpkg -l | grep proxy-ht
ii libapache2-mod-proxy-html 3.0.1-1.1 Apache2 filter module for HTML links rewriting

[James Page (james-page)]

Please see bug 988819 - this includes an apache2 change to make apache use dlopen as a fallback so that the .so file can be specificied without a full path.

Its currently in -proposed awaiting verification.

[Aditya V (kroq-gar78)]

Is this a duplicate of bug 1005425? The bugs seem almost exactly the same, and that one already has some fixes released. I, personally, can't tell the difference at all.

[Aditya V (kroq-gar78)]

Oops, I meant duplicate of bug 988819.

[Steve Langasek (vorlon)]

The Precise Pangolin has reached end of life, so this bug will not be fixed for that release