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In an effort to recreate a build environment that closely mimics the Launchpad buildds, the Ubuntu Security team has defined the following steps. This is in many ways an extension of SbuildLVMHowto. Additional information may be found in TestingEnvironment and README.sbuild_setup. If you're not a Ubuntu Security Team member, you might want to just read the simpler, more generic instructions for setting up sbuild without bothering with the security team's workflow.

Read these instructions if you want to build packages for the next, in-development version of Ubuntu on the current stable release, e.g. you want to build Quantal packages on your Precise system. Hint: you need to install debootstrap from -backports first.

This guide does not impose a specific version of Ubuntu; the latter is entirely up to you.

Setting up and using Sbuild with ddebs

For build and package testing, x86_64 users are strongly encouraged to create chroots for both amd64 and i386, whereas i386 users need only to create i386 chroots. Note, as of Ubuntu 19.10, i386 support is limited

Note: schroot does not trivially work on zfs root file systems. On jammy it might be possible to pass --type=zfs-snapshot to mk-sbuild.

Creating the schroots

1. Install sbuild and schroot:

   # optional: also install gnupg-agent or seahorse-agent
   $ sudo apt-get install sbuild schroot ubuntu-dev-tools moreutils

   Note: for focal it will probably need to install ca-certificate, since it's not installed by default with schroot.

   Note: if your host is based on xenial and you get to fail building for yakkety or zesty, some error messages like:

   Merged Build-Depends: build-essential, fakeroot
   Filtered Build-Depends: build-essential, fakeroot
   dpkg-deb: building package 'sbuild-build-depends-core-dummy' in '/<<BUILDDIR>>/resolver-Pj2d3h/apt_archive/sbuild-build-depends-core-dummy.deb'.
   gpg: /<<BUILDDIR>>/resolver-Pj2d3h/gpg/trustdb.gpg: trustdb created
   gpg: Warning: not using 'Sbuild Signer' as default key: No secret key
   gpg: all values passed to '--default-key' ignored
   gpg: no default secret key: No secret key
   gpg: signing failed: No secret key
   Failed to sign dummy archive Release file.

   You may need to update your host sbuild for yakkety version 0.71. See previous reported issue here and here for more information.

2. Make sure you are in the sbuild group. If you aren't, run the command above and re-login to your account:

   $ sudo adduser $USER sbuild

3. OPTIONAL: If /var doesn't have enough space, create a big partition for your chroots:

   $ sudo mkfs.ext4 /dev/sdXN
   $ sudo mkdir /srv/devel
   $ ls -l /dev/disk/by-uuid/|grep sdXN   # find the UUID for the disk
   lrwxrwxrwx 1 root root 10 2010-04-22 12:14 d9300709-7b77-4fcc-8d95-77cecdef9e51 -> ../../sdXN

   Add the partition to /etc/fstab (by UUID):

   UUID=d9300709-7b77-4fcc-8d95-77cecdef9e51 /srv/devel ext3 defaults,relatime 0 0

   Mount it:

   $ sudo mount /srv/devel
   $ df -h|grep devel
   /dev/sdXN             166G  188M  157G   1% /srv/devel

   Create the schroot directory:

   $ sudo mkdir /srv/devel/schroot

4. Create ~/.mk-sbuild.sources.ubuntu (can use simply .mk-sbuild.sources and also .mk-sbuild.sources.debian) substituting a local mirror, a nearby mirror or the official archive for '<mirror>'. Eg:

   deb http://<mirror>/ubuntu RELEASE main restricted universe multiverse
   deb-src http://<mirror>/ubuntu RELEASE main restricted universe multiverse
   #deb http://<mirror>/ubuntu RELEASE-updates main restricted universe multiverse
   #deb-src http://<mirror>/ubuntu RELEASE-updates main restricted universe multiverse
   deb http://<mirror>/ubuntu RELEASE-security main restricted universe multiverse
   deb-src http://<mirror>/ubuntu RELEASE-security main restricted universe multiverse

5. Setup for mounting $HOME:

   • Create a directory for the umt schroot profile:

     $ sudo mkdir /etc/schroot/umt

   • Copy the default profile's fstab:

     $ sudo cp /etc/schroot/default/fstab /etc/schroot/umt/

   • Append to /etc/schroot/umt/fstab:

     tmpfs           /run/shm        tmpfs   defaults        0       0
     tmpfs           /dev/shm        tmpfs   defaults        0       0

     If you use an encrypted home directory, your $HOME is mounted differently (eg /home/<username>/.Private is mounted on /home/<username>), so you will also have to add to /etc/schroot/mount-defaults:

     /home/<username>                            /home/<username>     none    rw,bind     0   0

   • Create /etc/schroot/umt/config:

     # Reuse copyfiles and nssdatabases from the default profile
     SETUP_COPYFILES="default/copyfiles"
     SETUP_NSSDATABASES="default/nssdatabases"
     
     # Do whatever the default script would do
     if [ -f "/etc/schroot/default/config" ]; then
         . /etc/schroot/default/config
     fi
     
     # Set our own fstab after the default script has been sourced
     SETUP_FSTAB="umt/fstab"
     # end script

6. Create ~/.sbuildrc:

   # Mail address where logs are sent to (mandatory, no default!)
   $mailto = 'username';
   
   # Name to use as override in .changes files for the Maintainer: field
   # (mandatory, no default!).
   $maintainer_name='Your Name <user@ubuntu.com>';
   
   # Directory for chroot symlinks and sbuild logs.  Defaults to the
   # current directory if unspecified. (Deprecated.) Leave this unset;
   # umt compare-bin relies upon this being unset.
   #$build_dir='/home/<username>/ubuntu/build';
   
   # Directory for writing build logs to
   $log_dir="/home/<username>/ubuntu/logs";
   
   # Override default sbuild dependency resolver (see 'man sbuild'). The default
   # resolver (apt) mostly works ok but not always (eg, oneiric libreoffice).
   # Use 'apt', 'aptitude', 'internal'. Can also use '--build-dep-resolver' with
   # sbuild or '--sbuild-dep-resolver' with umt.
   #$build_dep_resolver="apt";
   
   # don't remove this, Perl needs it:
   1;

   Then make the following directories (change if specified something different in ~/.sbuildrc):

   $ mkdir -p $HOME/ubuntu/logs
   $ mkdir -p $HOME/ubuntu/build # only if the $build_dir variable is set in ~/.sbuildrc

7. Create ~/.mk-sbuild.rc:

   # mk-sbuild build tunables -- SOURCE_CHROOTS_TGZ used with 'file' and SOURCE_CHROOTS_DIR with 'directory'
   SOURCE_CHROOTS_DIR="/srv/devel/schroot"         # default: /var/lib/schroot/chroots
   SCHROOT_PROFILE="umt"
   SCHROOT_CONF_SUFFIX="source-root-users=root,sbuild,admin
   source-root-groups=root,sbuild,admin
   preserve-environment=true"
   SKIP_UPDATES="1"
   SKIP_PROPOSED="1"
   # devscripts no longer installs correctly, so install it manually later
   DEBOOTSTRAP_INCLUDE=""

   What this does is tells schroot that the chroots are in "/srv/devel/schroot", and to append to the configuration of the chroot in /etc/schroot/schroot.conf the contents of SCHROOT_CONF_SUFFIX.

   IMPORTANT: The Ubuntu Security Team uses umt to build packages. umt automatically enables -proposed when building packages in for the current dev release. If you are not using umt to build packages, you'll need to determine if you should use SKIP_PROPOSED="1" in your ~/.mk-sbuild.rc.

   IMPORTANT: If you are using overlayfs, keep in mind that the writable overlay is in /var/lib/schroot/union/overlay by default (man 1 schroot). This means your build's compile while be on this partition and if there isn't enough space, your builds will fail. To change this to somewhere with more space, create an overlay directory (eg, sudo mkdir -p /srv/devel/schroot/overlay), then adjust your existing schroots to have 'union-overlay-directory=/srv/devel/schroot/overlay'. To use this by default for all schroots, modify ~/.mk-sbuild.rc to have 'union-overlay-directory=/srv/devel/schroot/overlay' somewhere in SCHROOT_CONF_SUFFIX.

8. Install Sendmail: sudo apt install sendmail

9. Finally, create the schroots (this assumes x86_64 host; for i386, omit amd64):

   $ sg sbuild   # only needed if you were added to the sbuild group during this session
   $ for i in noble mantic jammy focal bionic xenial trusty; do 
       mk-sbuild $i --arch=amd64 --skip-updates --debootstrap-mirror=http://<mirror>/ubuntu --distro=ubuntu
       if echo $i | grep -qE '(focal|jammy)'; then  # libeatmydata1 not available in focal and jammy on i386
         mk-sbuild $i --arch=i386 --skip-updates --skip-eatmydata --debootstrap-mirror=http://<mirror>/ubuntu --distro=ubuntu
       else
         mk-sbuild $i --arch=i386 --skip-updates --debootstrap-mirror=http://<mirror>/ubuntu --distro=ubuntu
       fi
   done
   $ exit # only needed if you used sg sbuild earlier; sg changes primary group

   If you want debian schroots:

   $ for i in buster bullseye stable testing unstable ; do
       mk-sbuild $i --arch=amd64 --skip-updates --distro=debian
   done

   For arm (see ARM/RootfsFromScratch for more details) :

   $ sudo apt-get install qemu-user-static
   $ mk-sbuild xenial --arch=armhf --skip-updates --distro=ubuntu

   See man mk-sbuild for details.

   Note 1: Oneiric and higher require you to run sbuild-update --keygen to generate a local archive key. This only needs to be done once and can be done as your user so long as you are in the 'sbuild' group. See manpage for details. (If you see this error when creating the keys 'gpg: can't create `(null)': Permission denied', then simply remove the existing keys in /var/lib/sbuild/apt-keys/* and try again.)

   Note 2: Debian schroots pull in exim4-base but Ubuntu systems do not. Due to Debian bug #565613 the passwd and group databases are pulled in from the host, overwriting what is in the chroot. Since Ubuntu by default does not have exim4-base installed, the user isn't there and you will end up with errors like this when updating the schroot at a later date: dpkg: syntax error: unknown group Debian-exim' in statusoverride file`. You can either create the user/group on the Ubuntu host or remove the exim4-base package from the schroot (this may not work with older Debian releases):

   $ schroot -u root -c source:sid-amd64 -- apt-get remove --purge -y --force-yes exim4-base
   $ schroot -u root -c source:sid-amd64 -- cp /var/lib/dpkg/statoverride-old /var/lib/dpkg/statoverride # remove Debian-exim line

   Note 3: mk-sbuild --arch armhf vivid may fail when running the 'finish.sh' script. If it does, go into the source:<chroot> as root and run /finish.sh. Eg: sudo schroot -c source:<chroot name> -u root /finish.sh

   Note 4: apt is configured to download the package translations files by default. These can be a source of build failures if they get corrupted and can cause apt-get update to take longer; therefore it can be useful to configure to disable downloading the translations files. To do so, do e.g.:

   $ schroot -c source:trusty-i386 -u root <<EOM
   echo 'Acquire::Languages "none";' > /etc/apt/apt.conf.d/99-no-translations
   EOM

   Note 5: yakkety and newer may fail with devscripts dependency errors such as

   W: Failure while configuring base packages.  This will be re-attempted up to five times.
   W: See /srv/devel/schroot/eoan-i386/debootstrap/debootstrap.log for details (possibly the package libnet-ssleay-perl is at fault)

   or error in /srv/devel/schroot/eoan-i386/debootstrap/debootstrap.log:

   dpkg: error processing package devscripts (--configure):
    dependency problems - leaving unconfigured
   Errors were encountered while processing:
    libnet-ssleay-perl
    libio-socket-ssl-perl
    liblwp-protocol-https-perl
    libwww-perl
    devscripts

   If so, then be sure to check this line DEBOOTSTRAP_INCLUDE="devscripts" in your ~/.mk-sbuild.rc is commented out. This then requires that for each schroot you need to go and purposely install devscripts in it, otherwise you'll notice packages fail to build. Eg

   $ schroot -c source:bionic-amd64 -u root -- apt-get install devscripts

   Note 6: if using foreign architectures in a chroot in a container, be sure that qemu-user-static is installed on the host and in the container so that /proc/sys/fs/binfmt_misc/qemu-arm from the host (which is bind mounted in the guest) correctly points to /usr/bin/qemu-arm-static. If you don't do this you might encoutner cryptic errors like "I: Running command: chroot /srv/devel/schroot/xenial-armhf /debootstrap/debootstrap --second-stage"

   Note 7: Uploading packages for Ubuntu 17.10 (artful) and later from a 17.04 (zesty) host or earlier requires installing devscripts from artful (or later) to properly setting signing .buildinfo files

   Note 8: Bionic and newer no longer support  union-type=overlayfs  .  cd /etc/schroot/chroot.d && sed -i 's/overlayfs/overlay/' sbuild-* .

10. Optional (experimental): It can often be useful to perform builds in /dev/shm, which is a tmpfs directory in RAM. While there are limitations on what you can compile and the number of concurrent builds that can be performed (based on how much memory your build machine has), building in /dev/shm can lead to much faster build times and reduce disk I/O. One way to achieve this is to configure additional full schroots for this, and specify the 'union-overlay-directory' directive. Another way to create a 'shared' source schroot like so:

    $ sudo sh -c "sed -e 's#]#-shm]#' -e 's#^\(directory=.*\)#\1\nunion-overlay-directory=/dev/shm/schroot/overlay#' /etc/schroot/schroot.conf > /etc/schroot/chroot.d/shm-overlays.conf"
    $ schroot --list

    This simply adds additional schroots based on what you already have (eg, if you have a bionic-amd64 schroot, this creates a bionic-amd64-shm definition in /etc/schroot/chroot.d/shm-overlays.conf). The caveat is that each shm schroot will have the same 'directory' as its corresponding non-shm schroot, so you shouldn't try to modify both 'source:bionic-amd64' and 'source:bionic-amd64-shm' at the same time. Once the shm schroot definitions are added, reference them via schroot (or umt) like any other schroot. Eg:

    $ schroot -c bionic-amd64-shm
    $ umt build -c bionic-amd64-shm

    Please note that the directory you specify for 'union-overlay-directory' must exist before using the shm chroot (can add an entry to /etc/rc.local). See man schroot.conf for more details. It might also be useful to remount /dev/shm with more memory than the default, which is 50% of RAM. Can adjust like so: sudo mount -o remount,size=75% /dev/shm. See man mount for details.

Install some additional packages

There are a few packages that will help you more closely mimic the buildd's so that the results of your local builds will be as close as possible to those used to build Ubuntu packages. Here is a list of helpful things to install. The general format is:

$ schroot -c source:bionic-amd64 -u root -- apt-get install package

Here are some helpful packages that are not normally installed by default:

• pkgbinarymangler - performs a number of consistency checks including important ones for Python packages. NOTE for it to strip translations, you'll need to adjust /etc/pkgbinarymangler/striptranslations.conf in the schroot.

• devscripts - includes debuild which is useful on its own and required by UMT for 'umt source' (this was included by default when using mk-sbuild until 12.04); do not use this if you want to reproduce Launchpad builds accurately ('sbuild' alone does not require debuild)

• For yakkety: apt-utils - to silence error message "debconf: delaying package configuration, since apt-utils is not installed"

• pkg-create-dbgsym - automatically build debug symbol ddeb packages. On Ubuntu 18.04 (bionic) and later, this is provided by 'debhelper' and doesn't need to be installed separately (though you may in

While mk-sbuild supports adding additional packages when creating the schroots via either the --debootstrap-include command line argument or by adding a DEBOOTSTRAP_INCLUDE setting to the ~/.mk-sbuild.rc (both methods take a comma-separated list of packages), in practice on Ubuntu 16.10 (yakkety) and later this can lead to problems. Instead, create the chroot without these options and install packages in a separate step as described above.

For typical security team build schroots on a bionic or later host, you may use:

$ for rel in noble mantic jammy focal bionic xenial trusty; do
  for arch in amd64 i386 ; do
    echo "# $rel"
    schroot -c source:$rel-$arch -u root -- apt-get update
    schroot -c source:$rel-$arch -u root -- apt-get install -y --force-yes pkgbinarymangler apt-utils
    echo $rel | grep -qE '(precise|trusty|xenial)' && schroot -c source:$rel-$arch -u root -- apt-get install -y --force-yes pkg-create-dbgsym # only on <bionic
    # devscripts is required by 'umt source', but note devscripts could introduce differences from LP builds
    schroot -c source:$rel-$arch -u root -- apt-get install -y --force-yes devscripts
    schroot -c source:$rel-$arch -u root -- apt-get clean
  done
done

Configure devscripts by creating a ~/.devscripts file with the following contents:

DEBSIGN_KEYID=<your keyid>
BTS_SMTP_HOST=<smtp provider>
BTS_SMTP_AUTH_USERNAME=<smtp user>
BTS_SMTP_AUTH_PASSWORD=<password>

Deleting a schroot

1. Remove the stanza for the chroot
   • rm the appropriate /etc/schroot/chroot.d/sbuild-* file

2. Remove the chroot from the disk:

   $ sudo rm -rf /var/lib/schroot/chroots/bionic-amd64

   or if on a separate partition:

   $ sudo rm -rf /srv/devel/schroot/bionic-amd64

Using the schroot

Using a schroot is similar to the chroot command but you specify the chroot and user you want to use rather than the directory.

$ schroot -c bionic-amd64 -u root
(bionic-amd64)root@foo:/home/user# apt-get install ...
(bionic-amd64)root@foo:/home/user# su user
(bionic-amd64)user@foo$ exit
exit
(bionic-amd64)root@foo:/home/user# exit
logout
$

Chroot to the other architectures with:

$ schroot -c bionic-i386 -u root
$ schroot -c bionic-armhf -u root

Or without root with:

$ schroot -c bionic-amd64

Or building via sbuild directly (see UMT, below, for the Ubuntu Security build scripts):

$ apt-get source foo
$ cd ./foo-*
... do work ...
$ dch -i
$ update-maintainer
$ debuild -S
$ sbuild -d bionic ../package_1.2.3-4.1.dsc

The updated source file, debs and ddebs (when pkg-create-dbgsym or new enough debhelper (focal+) in the schroot) appear in ../.

Maintaining the schroots

Can see a listing of all your chroots with:

$ schroot -l
chroot:bionic-amd64
chroot:bionic-i386
chroot:focal-amd64
chroot:focal-i386
chroot:precise-esm-amd64
...

Can get information on your chroots with schroot -i [-c chroot]. Eg:

$ schroot -i -c bionic-amd64
  --- Chroot ---
  Name                                 bionic-amd64
  Description                          bionic-amd64
  Type                                 directory
  Message Verbosity                    normal
  Users                                
  Groups                               sbuild root admin
  Root Users                           
  Root Groups                          sbuild root admin
  Aliases                              
  Preserve Environment                 true
  Default Shell                        
  Environment Filter                   ^(BASH_ENV|CDPATH|ENV|HOSTALIASES|IFS|KRB5_CONFIG|KRBCONFDIR|KRBTKFILE|KRB_CONF|LD_.*|LOCALDOMAIN|NLSPATH|PATH_LOCALE|RES_OPTIONS|TERMINFO|TERMINFO_DIRS|TERMPATH)$
  Run Setup Scripts                    true
  Configuration Profile                umt
  Script Configuration                 
  Session Managed                      true
  Session Cloned                       true
  Session Purged                       false
  Directory                            /srv/devel/schroot/bionic-amd64
  Personality                          undefined
  User Modifiable Keys                 
  Root Modifiable Keys                 
  User Data                            
    setup.config                       umt/config
    setup.copyfiles                    umt/copyfiles
    setup.fstab                        umt/fstab
    setup.nssdatabases                 umt/nssdatabases
  Filesystem Union Type                aufs
  Filesystem Union Overlay Directory   /srv/devel/schroot/overlay
  Filesystem Union Underlay Directory  /var/lib/schroot/union/underlay
  Source Users                         
  Source Groups                        
  Source Root Users                    root sbuild admin
  Source Root Groups                   root sbuild admin

The 'source:' (or '-source' in very old schroot) chroot is the pristine chroot and you shouldn't go into it unless you want to change something for all future schroots into the chroot. Eg, if you wanted to always have 'vim' installed in your bionic-amd64 chroot, use:

$ schroot -c source:bionic-amd64 -u root
$ apt-get install vim
$ exit

Now, any time you use the bionic-amd64 (ie, without 'source:'), vim will be installed.

It is also useful to keep your schroots up to date via cron. This can be done by creating $HOME/bin/schroot_update:

# '|' separated list of prefixes to not update
skipped="lucid|-shm(-|$)"

for d in `schroot -l | grep -- '\(^source:\|-source$\)' | egrep -v "($skipped)"`
do
    echo "Updating '$d'"
        schroot -q -c $d -u root -- sh -c 'apt-get -qq update && apt-get -qy -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confnew" dist-upgrade && apt-get clean'
    echo ""
done

Then adding a crontab entry for your user:

15 6 * * *  /home/<username>/bin/schroot_update

Expiring active schroot sessions

Sometimes needed if schroots are left hanging around due to a crash or reboot. You can expire all active schroot sessions with (see also /etc/default/schroot):

$ schroot -e --all-sessions    # see 'man schroot' for details

Enabling caching within the schroots

apt-cacher-ng

If you've chosen to use apt-cacher-ng to provide package caching without a dedicated local mirror, you may wish to create the file /etc/apt/apt.conf.d/acng in all your chroots with the correct Proxy setting:

Acquire::http { Proxy "http://127.0.0.1:3142"; };

This can be done with a shell script similar to this:

cd /srv/devel/schroot/
for d in * ; do cp /etc/apt/apt.conf.d/acng $d/etc/apt/apt.conf.d/ ; done

squid-deb-proxy

After setting up squid-deb-proxy, you have a configuration file in /etc/apt/apt.conf.d/<config> with apt's proxying setting:

Acquire::http::Proxy "http://127.0.0.1:8000";

As this should be present in schroots too, run the following command:

find /srv/devel/schroot/ -type d -name apt.conf.d  -exec cp /etc/apt/apt.conf.d/<config> {} \;

Ensure that the proxy is accessible locally, with something like:

sudo ufw allow in on lo to any proto tcp port 8000 comment 'squid-deb-proxy'

Also, if the private PPAs for ESM are going to be used as per the instructions below, ensure that access is allowed, using something like:

echo private-ppa.launchpadcontent.net | sudo sh -c 'cat >/etc/squid-deb-proxy/mirror-dstdomain.acl.d/20-esm'

Setting up a chroot for Extended Security Maintenance

Extra steps are required for setting up a chroot for ESM releases. Also Note: if your host is xenial the path to the archive keys is "/usr/share/keyrings/ubuntu-archive-keyring.gpg" and doesn't contain "removed" in the path.

1. Create the chroots:

       $ for rel in noble jammy focal bionic xenial trusty; do
           mk-sbuild $rel --name=$rel-esm --arch=amd64 --skip-updates --debootstrap-mirror=http://gb.archive.ubuntu.com/ubuntu $(echo $rel | grep -qE '(trusty|xenial)' && echo --debootstrap-keyring=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg) --distro=ubuntu
         done

   1. (OPTIONAL): If setting up i386 esm chroots (bionic, xenial and trusty only):

          $ for rel in bionic xenial trusty; do
              mk-sbuild $rel --name=$rel-esm --arch=i386 --skip-updates --debootstrap-mirror=http://gb.archive.ubuntu.com/ubuntu $(echo $rel | grep -qE '(trusty|xenial)' && echo --debootstrap-keyring=/usr/share/keyrings/ubuntu-archive-removed-keys.gpg) --distro=ubuntu
              schroot -c source:$rel-esm-i386 -u root -- apt-get -y install apt-transport-https ca-certificates
            done

2. Install the apt-transport-https and ca-certificates packages to communicate with a private Launchpad PPA:

       $ for rel in noble jammy focal bionic xenial trusty; do
           schroot -c source:$rel-esm-amd64 -u root -- apt-get -y install apt-transport-https ca-certificates
         done

3. Take note of the required information for accessing the PPA (for 12.04 this is ppa:ubuntu-esm/esm and for 14.04+ this is ppa:ubuntu-esm/esm-infra-security)

   1. Go to https://launchpad.net/people/+me/+archivesubscriptions

   2. Find the ESM Infrastructure Security (ppa:ubuntu-esm/esm-infra-security) row and click the "view" link to the right

   3. You'll need the apt sources lines as well as the key ID of the PPA archive key

   4. Repeat the last 2 steps for ESM Apps Security (ppa:ubuntu-esm/esm-apps-security).

   5. You'll need to configure the following repositories:

      • trusty: esm-infra-security only

      • xenial and bionic: both esm-infra-security and esm-apps-security

      • focal or newer: esm-apps-security only

4. Restrict file access to the ESM apt sources list file prior to writing your credentials to the file

   •     $ for rel in noble jammy focal bionic xenial trusty; do
             schroot -c source:$rel-esm-amd64 -u root -- sh -c 'cd /etc/apt/sources.list.d; touch esm-ppa.list; chown root:sudo esm-ppa.list; chmod 640 esm-ppa.list'
           done

5. Add the apt sources lines to a new sources file (enter your LP user and token from the steps above when prompted):

       $ read -p "PPA username: " user ; read -sep "ESM-Infra PPA token (hidden): " itoken ; echo \n ;  read -sep "ESM-Apps PPA token (hidden): " atoken ; echo \n
         for rel in noble jammy focal bionic xenial trusty; do
         if echo $rel | grep -vqE 'trusty'; then  # only trusty doesn't get apps
           echo "deb https://$user:$atoken@private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu $rel main"
           echo "deb-src https://$user:$atoken@private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu $rel main"
         fi | schroot -c source:$rel-esm-amd64 -u root -- tee -a /etc/apt/sources.list.d/esm-ppa.list | sed -e "s/$atoken/HIDDEN/"
         if echo $rel | grep -qE 'trusty|xenial|bionic'; then  # focal and newer don't need infra
           echo "deb https://$user:$itoken@private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu $rel main"
           echo "deb-src https://$user:$itoken@private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu $rel main"
         fi | schroot -c source:$rel-esm-amd64 -u root -- tee -a /etc/apt/sources.list.d/esm-ppa.list | sed -e "s/$itoken/HIDDEN/"
       done ; unset user itoken atoken

6. Import the PPA key:

       $ for rel in noble jammy focal bionic xenial trusty; do
           schroot -c source:$rel-esm-amd64 -u root -- apt-key adv --recv-key --keyserver keyserver.ubuntu.com <PPA_ARCHIVE_KEY_ID>
         done
   
       Note: See 3. 5. above for guidance on which PPA key IDs are needed for each release.

7. Synchronize the package index files and upgrade any outdated packages:

       $ for rel in noble jammy focal bionic xenial trusty; do
           schroot -c source:$rel-esm-amd64 -u root -- apt-get update
           schroot -c source:$rel-esm-amd64 -u root -- apt-get -y dist-upgrade
         done

8. Install pkgbinarymangler, apt-utils, pkg-create-dbgsym and devscripts on esm schroots, too:

       $ for rel in noble jammy focal bionic xenial trusty; do
           echo "# $rel"
           schroot -c source:$rel-amd64 -u root -- apt-get install -y --force-yes pkgbinarymangler apt-utils
           echo $rel | grep -qE '(precise|trusty|xenial)' && schroot -c source:$rel-amd64 -u root -- apt-get install -y --force-yes pkg-create-dbgsym # only on <bionic
           # devscripts is required by 'umt source', but note devscripts could introduce differences from LP builds
           schroot -c source:$rel-amd64 -u root -- apt-get install -y --force-yes devscripts
           schroot -c source:$rel-amd64 -u root -- apt-get clean
         done

You can now use the ESM chroots to prepare source packages and perform local test builds using UMT, as documented below. It is recommended you also install the supplementary packages as described in 'Install some additional packages', above.

Setting up and using UMT

In an effort to both mimic the official buildd's and standardize building of packages, the Ubuntu Security team wrote UMT (Uncomplicated Massive Tool), a part of ubuntu-security-tools. This branch has helper scripts and tools for performing various tasks. Arguably the most important is UMT, as this is the primary tool the Ubuntu Security team uses for building packages. Much of this can be seen in the README.

UMT has a number of commands to help make the build process repeatable and easy to follow. The main things to remember are that:

• all the commands are run in the toplevel source (except 'download')
• ../* (relative to the toplevel source) will contain the original source package
• ../source (relative to the toplevel source) will contain your new source package and debdiff
• ../binary (relative to the toplevel source) will contain your new binary packages (and ddebs when pkg-create-dbgsym or a new enough debhelper is installed)

• ../reports (relative to the toplevel source) will contain the debcompare output after running umt compare-bin

Setting up UMT

First, download the ubuntu-security-tools and ubuntu-qa-tools branches:

$ git clone git+ssh://<USER>@git.launchpad.net/ubuntu-security-tools
$ git clone git+ssh://<USER>@git.launchpad.net/ubuntu-qa-tools
$ git clone git+ssh://<USER>@git.launchpad.net/ubuntu-cve-tracker

Add the UST, UCT and UQT environment variables to your startup scripts (eg ~/.bashrc) and have them point to your branches:

export UST="$HOME/git-pulls/ubuntu-security-tools"
export UQT="$HOME/git-pulls/ubuntu-qa-tools"
export UCT="$HOME/git-pulls/ubuntu-cve-tracker"

Then add umt to your PATH.

$ ln -s $UST/build-tools/umt $HOME/bin/umt

Link $UQT and $UCT.

$ ln -s $UQT/common/lpl_common.py $UCT/scripts/lpl_common.py

Finally, to enable basic bash-completion support for umt add something like the following to your ~/.bash_completion file:

if which umt 1>/dev/null; then
  source $(dirname $(realpath $(which umt)))/umt-completion.bash
fi

Make sure the DEBEMAIL and DEBFULLNAME environment variables are setup in your startup scripts (eg ~/.bashrc):

export DEBEMAIL='user@ubuntu.com'
export DEBFULLNAME='Your Name'

Create ~/.ubuntu-security-tools.conf to have:

# list of all active releases (included devel)
release_list="trusty xenial bionic focal jammy mantic noble"

# name of the current devel release
# see https://wiki.ubuntu.com/SecurityTeam/ReleaseCycle for schedule
# to modify this variable
release_devel="noble"

# non-Ubuntu releases (used for schroots, VMs, etc) from Debian
release_extras="buster bullseye stable unstable testing"

# root of the sbuild log output (i.e. where $log_dir in ~/.sbuildrc is bind mounted in the chroot via /etc/schroot/mount-defaults)
pkgbuild_logs="/home/<username>/ubuntu/logs"

# path when building with ccache (bind mounted in the chroot via /etc/schroot/mount-defaults)
pkgbuild_ccache="/scratch/ccache"

# sets 'ulimit -v $pkgbuild_ulimit_v'. Set to "unlimited" for no limit. Some
# builds require a limit (eg, gcc) and some prefer a much higher limit (eg
# openoffice.org/libreoffice). If not set, umt will default to 'unlimited'
# except for packages that are known to need a smaller value.
#pkgbuild_ulimit_v="1024000"
#pkgbuild_ulimit_v="unlimited"

# the URL for the regular Ubuntu archive or mirror
build_tools_sbuildmirror="http://archive.ubuntu.com/ubuntu"

# currently used by check_source_packages
package_tools_name="Your Name"
package_tools_email="user@ubuntu.com"
package_tools_type="security"
package_tools_repo_url="http://192.168.122.1/debs/testing"
package_tools_repo_base="/var/www/html/debs/testing"
#package_tools_force_rmadison="yes"

# currently used by ddput
upload_tools_ddput_security="security:RELEASE"

Note: umt changelog -r expects release_list to be sorted by release date starting by older releases. In case of setting up the environment to also support ESM, ESM entries must be placed right after their base release. E.g. (release_list="trusty trusty/esm xenial esm-infra/xenial esm-apps/xenial bionic esm-infra/bionic esm-apps/bionic focal esm-apps/focal jammy esm-apps/jammy lunar mantic noble")

Note 2: 192.168.122.1 is the default IP address through which the guest OS can access the host one.

Setting up your apt sources

Your apt sources need to be adjusted to have deb-src lines for all supported releases (and Debian releases). A helper script in ubuntu-security-tools can be used for this:

$ $UST/build-tools/build-sources-list | sudo sh -c 'cat > /etc/apt/sources.list.d/ubuntu-security.list'

This will look at build_tools_sbuildmirror, release_list, release_devel and release_extras in $HOME/.ubuntu-security-tools.conf and generate the appropriate deb-src lines.

apt Sources for Debian (For reference, do not add these if you ran the build-sources-list tool above.)

Add the following Debian repositories in the generated /etc/apt/sources.list.d/ubuntu-security.list file:

# Buster
deb-src http://deb.debian.org/debian buster main contrib non-free
deb-src http://deb.debian.org/debian buster-updates main contrib non-free
deb-src http://security.debian.org/ buster/updates main contrib non-free

# Stable
deb-src http://deb.debian.org/debian stable main contrib non-free non-free-firmware
deb-src http://deb.debian.org/debian stable-updates main contrib non-free non-free-firmware
deb-src http://security.debian.org/debian-security stable-security main contrib non-free non-free-firmware

# Testing
deb-src http://deb.debian.org/debian testing main non-free non-free-firmware

# Unstable
deb-src http://deb.debian.org/debian unstable main non-free non-free-firmware

apt Sources for ESM

1. Access your private subscriptions at https://launchpad.net/people/+me/+archivesubscriptions.

2. Search for the ESM Infrastructure Security PPA and click on View on the right.

3. Get your access token from one of the URLs specified in the code block. It should follow the username present in the HTTP basic authentication schema (i.e. between the characters : and @).

4. Repeat the second step with the ESM Apps Security PPA.

5. Create a /etc/apt/auth.conf.d/esm-ppas.conf file with restrictead read access, to protect private PPA credentials:

       $ sudo touch /etc/apt/auth.conf.d/esm-ppas.conf
       $ sudo chmod 600 /etc/apt/auth.conf.d/esm-ppas.conf

6. Populate the contents of the /etc/apt/auth.conf.d/esm-ppas.conf file (ensuring its previous permissions are kept):

   machine private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu
   login <username>
   password <second_token>
   
   machine private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu
   login <username>
   password <second_token>

7. Create a /etc/apt/sources.list.d/esm-ppas.list file with:

   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu jammy main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu bionic main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu focal main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu xenial main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-apps-security/ubuntu trusty main
   
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu jammy main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu bionic main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu focal main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu xenial main
   deb-src https://private-ppa.launchpadcontent.net/ubuntu-esm/esm-infra-security/ubuntu trusty main

Securing and Updating apt

Then, setup secure apt:

$ sudo apt-get install ubuntu-keyring  # may already be installed
$ sudo apt-get install debian-archive-keyring
$ sudo cp /usr/share/keyrings/debian-archive-keyring.gpg /etc/apt/trusted.gpg.d/
$ curl -o ~/esm-ppa.asc 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0xdbb1fc89762bf6b96707c4059bc0a1a1622cf918'
$ sudo mv ~/esm-ppa.asc /etc/apt/trusted.gpg.d/
$ sudo apt-get update

Setting up dput

Create/update ~/.dput.cf to have:

[DEFAULT]
method = sftp
login = <your Launchpad account name>

# Soyuz security
# dput security:bionic ./*_source.changes
[security]
fqdn = ppa.launchpad.net
incoming = ~ubuntu-security/ppa/ubuntu/%(security)s

# Soyuz security-proposed
# dput security-proposed:bionic ./*_source.changes
[security-proposed]
fqdn = ppa.launchpad.net
incoming = ~ubuntu-security-proposed/ppa/ubuntu/%(security-proposed)s

# Soyuz esm
# dput esm:precise ./*_source.changes
[esm]
fqdn = ppa.launchpad.net
incoming = ~ubuntu-security/esm/ubuntu/%(esm)s

# Soyuz security-staging
# NOTE: ppa is public. can be used for test builds, dev release development
# dput security-staging:precise ./*_source.changes
[security-staging]
fqdn = ppa.launchpad.net
incoming = ~ubuntu-security/ubuntu-security-staging/ubuntu/%(security-staging)s

# Soyuz security-staging-private
# dput security-staging-private:precise ./*_source.changes
[security-staging-private]
fqdn = ppa.launchpad.net
incoming = ~ubuntu-security/ubuntu-security-staging-private/ubuntu/%(security-staging-private)s

Using umt

umt basically works like so:

$ umt <command> <options>

You can see all the commands with umt --help. Eg:

$ umt help
...
Uncomplicated Massive Tool (umt)
umt COMMAND [OPTIONS]

COMMAND:
search       List best source packages for each release
download     Get source packages and unpack
changelog    sdch-like new entry creation or extraction of changelog from prior
             release (dch-repeat-like)
source       Produces source package from current directory of unpacked source
binary       Produces binary packages and other outputs from ../source source
build        Do both above
build-orig   Temporarily builds the previous release to get the log file
sign         Sign the packages
check        Do a check-source-package
compare-log  Compare the build log against the prior version's log
compare-bin  Compare the binary debs against the prior version's binaries
repo         Copy all built packages into local repository
upload       Uploads with dput

OPTIONS:
type "umt COMMAND -h" to get a list of options for each command.

Download a package

To download packages for all releases:

$ umt download <source package>

For each release, this will put the source package in './<source package name>/<release>' and perform dpkg-source -x on it.

To download a package for a single release:

$ umt download -r bionic <source package>

Source build

$ umt source
Package is: postgresql-8.1
Version is: 8.1.21-0ubuntu0.6.06
Version with epoch is: 8.1.21-0ubuntu0.6.06
Upstream version is: 8.1.21
Changelog release is: dapper
Release is: dapper
Pocket is: security
Component is: main 
Need -sa for source build? False
DEB_BUILD_OPTIONS: 
Dependency resolution: auto
Chroot: dapper-amd64
Censored sources.list for main build
Get:1 http://<mirror> dapper Release.gpg [189B]
Hit http://<mirror> dapper Release  
...
dpkg-buildpackage: source only upload (original source is included)
Copying files to '../source'
Skipping debdiff (only one dsc found)
SUCCESS: source package in '../source'

Some useful options for umt source are:

• --force-orig (forces inclusion of orig.tar.gz via use of -sa)
• -v VERSION (use changelog information from all versions strictly later than VERSION)
• -c CHROOT (specify the chroot to use instead of the default)
• -s (skip pocket and release consistency checks -- useful when doing non-security builds)

Binary build

$ umt binary
Package is: postgresql-8.1
Version is: 8.1.21-0ubuntu0.6.06
Version with epoch is: 8.1.21-0ubuntu0.6.06
Upstream version is: 8.1.21
Changelog release is: dapper
Release is: dapper
Pocket is: security
Component is: main 
Need -sa for source build? False
DEB_BUILD_OPTIONS: 
Chroot: dapper-amd64
core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 20
file size               (blocks, -f) unlimited
pending signals                 (-i) 16382
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) unlimited
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited
sbuild command is: /usr/bin/sbuild --setup-hook /tmp/umt-ws7rLM -d dapper-amd64 -A postgresql-8.1_8.1.21-0ubuntu0.6.06.dsc
Sessions still open, not unmounting
sbuild (Debian sbuild) 0.59.0 (02 Aug 2009) on ...
...
Built successfully
/var/lib/schroot/mount/dapper-amd64-a5089ef6-62ff-48e9-9977-9613ca584e3c/build/jamie-postgresql-8.1_8.1.21-0ubuntu0.6.06-amd64-kQ6GiK
--
Not removing build depends: cloned chroot in use

You can do a simple no-change rebuild (useful for examining the build log) with:

$ umt build -s [-c <chroot>]

You can also build the previous version (needed for log comparing) with:

$ umt build-orig

Signing a package

To sign your own package:

$ umt sign

To sign a sponsored package:

$ umt sign -k

Verifying a package

$ umt compare-log
... diff of last build log and current build opened in EDITOR ...

$ umt compare-bin
... creates reports in ../reports using debcompare (from ubuntu-security-tools) ...

$ umt check
Running '<absolute path to>/security-tools/package-tools/check-source-package -s -T dapper-security -b ../binary ../source/elinks_0.10.6-1ubuntu3.4.dsc' ...
Checking: elinks_0.10.6-1ubuntu3.4.dsc
Mode: security
Debdiff: elinks_0.10.6-1ubuntu3.4.debdiff

Retrieving madison output:      pass
Binary build:                   pass
PGP (verify dsc):               pass
PGP (verify source.changes):    pass
PGP (signature present):        pass
Distribution:                   pass
Pocket:                         pass
Maintainer:                     pass
Changed-By:                     pass
Source has orig.tar.gz:         pass
Recent date:                    pass
Output of diffstat:             
 elinks-0.10.6/debian/changelog       |   16 ++++++++++++++++
 elinks-0.10.6/src/intl/charsets.c    |   24 ++++++++++++------------
 elinks-0.10.6/src/protocol/smb/smb.c |    7 +++++++
 3 files changed, 35 insertions(+), 12 deletions(-)
Version:                        pass
Newest version:                 pass
 Current: 0.10.6-1ubuntu3.4
 Found:   0.10.6-1ubuntu3.3
Diff chaff:                     pass
Merged changelog:               ignored
Patch system:                   patchless? (skipped patch system checks)
Patch tagging:                  pass (no patches)
Check existing binaries:        
 found existing: elinks dapper-security
 found existing: elinks-lite dapper-security/universe
 Total: 2 (new=0, existing=2)
Reverse Debdiff:                pass
Bad files:                      pass
Vcs files in source:            pass
------
PASS

Uploading a package

$ umt upload
Source is: elinks
Version is: 0.10.6-1ubuntu3.4
Version with epoch is: 0.10.6-1ubuntu3.4
Distribution is: dapper
Pocket is: security
Destination is: ubuntu
Validating elinks version 0.10.6-1ubuntu3.4 ...
...

In general, if there is a problem with the upload, the uploader will be sent an email. If there is a problem with verifying the signature on the package, an email will not be sent. If this happens, verify that launchpad has the most up to date version of your key and if it doesn't, update the key (ie, gpg --keyserver keyserver.ubuntu.com --send-key <ID>).

Local apt repository

It is often useful to test the binaries before uploading to the security queue (after which, those binaries should be tested fully). UMT provides some functionality for copying the newly built binaries into a local repository. To use:

1. install the necessary software:

   $ sudo apt-get install apt-utils moreutils apache2

2. create a directory in /var/www/html, writable by you:

   $ sudo mkdir -p /var/www/html/debs/testing
   $ sudo chown -R $USER:$USER /var/www/html/debs

Now, after building your binaries you can copy them into the local apt repo:

$ umt repo
Package is: hello
Version is: 2.4-3ubuntu1
Version with epoch is: 2.4-3ubuntu1
Upstream version is: 2.4
Changelog release is: bionic
Release is: bionic
Pocket is: security
Component is: main 
Need -sa for source build? False
DEB_BUILD_OPTIONS: 
Repository: /var/www/debs/testing/bionic
Copying 'hello_2.4-3ubuntu1_i386.deb'...

You need a passphrase to unlock the secret key for
user: "Your Name <user@ubuntu.com>"
1024-bit DSA key, ...

--                
/var/www/debs/testing/bionic updated

Use:
  deb http://192.168.122.1/debs/testing/ bionic/
  deb-src http://192.168.122.1/debs/testing/ bionic/
--
SUCCESS

The output shows the progress of the command as well as the appropriate lines to add to a sources.list file to apt-get the packages. Keep in mind:

• this will copy all binaries found in ../binary relative to your toplevel source (be careful if you compiled i386 and amd64 binaries at different times to be sure you are testing what you thing you are testing)

• binaries are copied to the release directory under package_tools_repo_base. Eg, in this example running umt repo on a package with bionic-security as the distribution name results in the binaries being copied to /var/www/html/debs/testing/bionic. Note: prior to Ubuntu 14.04 LTS, the default DocumentRoot is /var/www instead of /var/www/html

• umt repo is not particularly smart -- it will overwrite packages of the same version and leave everything else in the local repo alone. It is often useful to clean out your local repository with something like:

  $ rm -rf /var/www/debs/testing/*/*

  The update_repo command from ubuntu-security-tools/repo-tools can also be used to update the local repository information (eg Sources, Packages, etc).

Building sources with packages in your local repository

Say that package bar depends on a particular version of package foo, and they need to be updated together. Build foo like normal, then use umt sign && umt repo to put foo into your local repository. Then when building bar, add --add-repo to the build command (eg, umt build --add-repo) and your local repository will be added to the build and bar can be built with your local foo. (Here is an alternative/related approach.)

For this to work, you should add your GPG key that is used to sign your packages to your schroots. Eg:

for rel in lucid precise quantal saucy trusty utopic ; do
  for arch in amd64 i386 ; do
     gpg --armor --export <your key id> | schroot -c source:$rel-$arch -u root apt-key add -
  done
done

copy_sppa_to_repos

The ubuntu-security-tools branch also has a script for copying files from LP into your local apt repository, which is very useful for testing the binaries people will actually install. To use:

$ $UST/repo-tools/copy_sppa_to_repos srcpkg1 srcpkg2

Please note, this requires a configured ubuntu-cve-tracker to work. You will also need to install several python packages:

$ apt install python-progressbar python-apt python-launchpadlib python-configobj

Typical package build procedure

$ umt download -r bionic foo
$ cd foo/bionic/foo-*    # cd into the toplevel source
$ umt changelog         # runs 'dch -i' with appropriate arguments for security updates
... perform your patching, etc ...
$ umt build             # runs 'umt source' followed by 'umt binary'
$ umt build-orig        # builds the prior version, for comparing with your new version 
$ umt compare-log
$ umt compare-bin
... view compare-bin results in ../reports/ ...
$ umt check
$ umt repo
... in a VM, apt-get packages from local repository to test the packages ...
$ umt sign
$ umt upload

ESM package build procedure

$ umt download -r precise/esm foo
$ cd foo/precise_esm/foo-*       # cd into the toplevel source
$ umt changelog                # runs 'dch -i' with appropriate arguments for security updates
... perform your patching, etc ...
$ umt build -c precise-esm-amd64 # runs 'umt source' followed by 'umt binary'
$ umt build-orig -sr precise/esm -c precise-esm-amd64 # builds the prior version, for comparing with your new version 
$ umt compare-log
# if the previous binaries to compare against are in the the Precise archive:
$ umt compare-bin
# otherwise, if the previous binaries to compare against are in ppa:ubuntu-esm/esm:
$ umt compare-bin --prev-ppa=ubuntu-esm/esm
... view compare-bin results in ../reports/ ...
$ umt check
$ umt repo
... in a VM, apt-get packages from local repository to test the packages ...
$ umt sign
$ umt upload -d esm:precise

Using UMT with git-buildpackage

UMT can also easily be used with packages that are maintained with git-buildpackage. You can run the commands which build packages using gbp's --git-builder option.

Note: mariadb-5.5 and mariadb-10.0 are examples of packages that are maintained using gbp. Full instructions on sponsoring MariaDB security uploads are available here.

To perform a source build:

$ gbp --git-builder='umt source'

To perform a full source and binary build:

$ gbp --git-builder='umt build'