Slackware guest on Linux-VServer

• Info: http://linux-vserver.org/
• What is Linux-Vserver: https://en.wikipedia.org/wiki/Linux-VServer
• Download my patch and installer script: /files/linux-vserver/slack_vserver.tar.gz

Linux-Vserver is an open source software which acts as a virtual private server implementation done by adding operating system-level virtualization capabilities to the Linux kernel.

This means that all guests share the same kernel and they don't need to provide hardware support.

The purpose of this note is to show how to setup a guest based on Slackware into a Slackware host. What follows was tested on Slackware 15.0, 14.2, 14.1, 14.0, 13.37 and 13.1 (both 32b and 64b). I will assume that you have a Linux-Vserver box working. You can find here a quick and easy howto concerning Linux-Vserver installation and configuration (patching the kernel + utils-vserver installation).

Download

wget https://notes.sagredo.eu/files/linux-vserver/slack_vserver.tar.gz
tar xzf slack_vserver.tar.gz
cd slack_vserver
ls

You have downloaded the following files:

• PKG_LIST_15.0 is the package list to be installed in the guest
• download_slack_pkg.sh is a script that you can use to download all the PKG_LIST. If you use this scriptlet all the package will be stored in the slackware[64]-version_pkg sub-folder.
• make_slack_vserver.sh is the shell script that you have to adjust. It installs the guest.
• rc is the startup script for the virtual server. It will be automatically copied in /etc/rc.d/init.d/rc
• slackware-15.0.patch is the patch which modifies the rc.x files. It must be applyed after the creation of the vserver process. In the patch I switched off all the mounts and executable that are related to the hardware. Comments would be welcome about this :-).

Download the packages

First of all select a minimal set of packages to be installed on the virtual server. This list of less than 200 packages is based on the Minimal System reported at http://www.slackwiki.com/Minimal_System without all hardware, kernel and multimedia related packages. The install leads to a guest of about 500 MB of size. This set fits with the installation of a complete virtual web server including apache, apache-tomcat, php, mysql, postgresql, qmail and related, ftp, named.

I assume that the packages to be installed are stored in the slackware{$ARCH}-{$VERSION}_pkg folder. If not, adjust its location editing the make_slack_vserver.sh script.

You can download my minimal set of packages running the shell script download_slack_pkg.sh. It can create a folder like slackware{$ARCH}-{$VERSION}_pkg for you, where $ARCH has to be "64" if you want to download 64b packages or empty otherwise, while $VERSION is the Slackware version, so it's something like "15.0".

#!/bin/bash
#
# 2021.10.13
# Removed lines like
# if [ ! -f ${FILE}*.t?z ]; then
# because they prevented packages with same prefix to be downloaded (i.e. glibc, glibc-i18n)
#
# 2020.11.04
# Do not download patches if version is -current
#
# 2016.06.08
# Now the script parses comments in the package list (thanks to Mark Colclough)

VERSION="15.0" # Slackware version
ARCH="64" # you can put 64 for 64b cpu just to separate 64/32 download folders

# Put here your favourite Slackware repository
SRC=ftp://ftp.gwdg.de/pub/linux/slackware/slackware${ARCH}-${VERSION}
#ftp://ftp.slackware.no/slackware/slackware${ARCH}-${VERSION}

# put here your pkg list
LIST=${PWD}/PKG_LIST_${VERSION}

# the directory where you unpacked slack_vserver.tar.gz
# $PWD should work, otherwise put /path/to/slack_vserver
SETUP=../ #$PWD

# the directory where you want to download the slackware packages
PACKAGES=${SETUP}/slackware${ARCH}-${VERSION}_pkg

# create the folder where the pkg will be downloaded
if [ ! -d $PACKAGES ]; then mkdir -p $PACKAGES; fi

# clean the $PACKAGES dir
rm -r ${PACKAGES}/*

# create the "patches" sub-folder
if [ ! -d ${PACKAGES}/patches ]; then mkdir -p ${PACKAGES}/patches; fi

# download
cd $PACKAGES

if [ -f $LIST ]; then
        while read LINE
            do
		[ "$LINE" ] || continue
		[ "${LINE#\#}" = "$LINE" ] || continue

		FILE=$(echo $LINE | sed -e "s/^.*\/\(.*\)/\1/")
		wget ${SRC}/slackware${ARCH}/${LINE}*.t?z
        done < $LIST
else
	echo "Can't find $LIST file."
	exit 1
fi

# download packages from the patches folder
if [ ${VERSION} != "current" ]; then
	cd ${PACKAGES}/patches

	if [ -f ${LIST} ]; then
        	while read LINE
		do
			IFS='/' read -ra PKG <<< "$LINE"
                	[ "${PKG#\#}" = "${PKG}" ] || continue
			PKG_LEN=${#PKG[@]}
        	        if [ $PKG_LEN == 2 ]; then wget ${SRC}/patches/packages/${PKG[1]}*.t?z; fi
        	done < $LIST
	else
		echo "Can't find $LIST file."
	        exit 1
	fi
fi

Adjust the package PKG_LIST_15.0, enter your favorite ftp server and run from the command line

./download_slack_pkg.sh

NB: this script tries also to overwrite the packages downloaded from the /slackware folder with the updates belonging to the /patches dir.

Make the guest

Now let's create the guest and install the packages. As you know you must choose at least a "name", a "context" and an ip. In addition you have to modify most of the rc.* startup scripts removing all the hardware related daemons, and finally replace the /dev dir.

This is done adjusting and running the script make_slack_vserver.sh:

#!/bin/bash
#
# v. 2021.11.02
# Author: Roberto Puzzanghera
# Thanks to Mark Colclough for corrections
#
# Installs a Slackware guest into a linux-vserver host (http://linux-vserver.org)
# More info here: https://notes.sagredo.eu/other-contents-186/slackware-guest-on-linux-vserver-7.html
#

# adjust this to where your things live
NAME=vtest
HOSTNAME=$NAME.yourdomain.tld
IPv4=168.192.1.1
IPv6=2001:41d0:1:c174::1
INTERFACE=eth0:$IPv4/24
INTERFACE6=eth0:$IPv6/64
CONTEXT=101
VERSION=15.0 # Slackware version
ARCH=64 # you can put 64 for 64b cpu just to separate 64/32 download folders

# where is the vservers dir? default is /vservers
VDIR=/vservers

# the directory where you unpacked slack_vserver.tar.gz
# $PWD should work, otherwise put /path/to/slack_vserver
SETUP=$PWD

# the directory where you downloaded the slackware packages
PACKAGES=$SETUP/slackware${ARCH}-${VERSION}_pkg

# the path to rc script file (leave as is)
RC=$SETUP/rc

###################################################################################### end configuration
############################################################################ do not touch anything below

# sanity check

if [ ! -d "$VDIR" ]; then
        echo
        echo "Can't find VDIR dir: $VDIR"
        echo "Exiting"
	echo
        exit 1
fi
if [ ! -d "$SETUP" ]; then
        echo
        echo "Can't find SETUP dir: $SETUP"
        echo "Exiting"
	echo
        exit 1
fi
if [ ! -d "$PACKAGES" ]; then
        echo
        echo "Can't find PACKAGES dir: $PACKAGES"
        echo "Exiting"
        echo
        exit 1
fi
if [ ! -f "$RC" ]; then
        echo
        echo "Can't find RC path: $RC"
        echo "Exiting"
        echo
        exit 1
fi

# if everything is ok start the install

echo
echo "Making skeleton..."
vserver $NAME build -m skeleton \
        --hostname $HOSTNAME \
        --interface $INTERFACE \
        --interface $INTERFACE6 \
        --context $CONTEXT \
        --flags lock,virt_mem,virt_uptime,virt_cpu,virt_load,sched_hard,hide_netif \
        --initstyle sysv
echo "...done"
echo

echo "Moving the /dev folder to a temp dir the /dev folder..."
mv $VDIR/$NAME/dev $VDIR/$NAME/dev2
sleep 3
echo

echo "Installing packages..."
sleep 3
cd $PACKAGES
installpkg --root $VDIR/$NAME *.t?z;
# install patches if dir not empty
if [ "$(ls -A patches)" ]; then ROOT=$VDIR/$NAME upgradepkg patches/*.t?z; fi
echo

echo
echo "Installing the rc script to /etc/rc.d/init.d/rc ..."
cp $RC $VDIR/$NAME/etc/rc.d/init.d/
chown root:root $VDIR/$NAME/etc/rc.d/init.d/rc
chmod +x $VDIR/$NAME/etc/rc.d/init.d/rc
echo

echo "Removing x flag to rc.sshd, removing not needed rc scripts..."
chmod -x $VDIR/$NAME/etc/rc.d/rc.sshd
rm $VDIR/$NAME/etc/rc.d/rc.cpufreq $VDIR/$NAME/etc/rc.d/rc.modules* \
   $VDIR/$NAME/etc/rc.d/rc.setterm \
   $VDIR/$NAME/etc/rc.d/rc.inet1* $VDIR/$NAME/etc/rc.d/rc.loop \
   $VDIR/$NAME/etc/rc.d/rc.K $VDIR/$NAME/etc/rc.d/rc.0 \
   $VDIR/$NAME/etc/rc.d/rc.S $VDIR/$NAME/etc/rc.d/rc.4 \
   $VDIR/$NAME/etc/rc.d/rc.inetd
echo

echo "Adjusting HOSTNAME, hosts, resolv.conf, profile. Check them later..."
cp /etc/resolv.conf $VDIR/$NAME/etc/
cp /etc/localtime $VDIR/$NAME/etc/
rm $VDIR/$NAME/etc/profile
cp /etc/profile $VDIR/$NAME/etc/
echo $HOSTNAME > $VDIR/$NAME/etc/HOSTNAME
echo "127.0.0.1 localhost" > $VDIR/$NAME/etc/hosts
echo "$IP $HOSTNAME $NAME" >> $VDIR/$NAME/etc/hosts
touch $VDIR/$NAME/etc/mtab
touch $VDIR/$NAME/etc/fstab
echo

echo "Restoring /dev2 to /dev"
rm -r $VDIR/$NAME/dev
mv $VDIR/$NAME/dev2 $VDIR/$NAME/dev
echo

echo "Updating ca-certificates"
chroot $VDIR/$NAME usr/sbin/update-ca-certificates --fresh 1> /dev/null 2> /dev/null

echo
echo -n "Do you want that I apply the patch for you y/n? [y] "
read VAR_PATCH

if [ "$VAR_PATCH" = 'y' ] || [ "$VAR_PATCH" = 'Y' ] || [ "$VAR_PATCH" = '' ]; then

	if [ ! -f "${SETUP}/linux-vserver_slackware-${VERSION}.patch" ]; then
	      	echo
		echo "Can't find any PATCH here: ${SETUP}/linux-vserver_slackware-${VERSION}.patch"
		echo "Exiting"
		echo
		exit 1
	fi

        cd ${VDIR}/${NAME}/etc/rc.d
        patch -p1 < ${SETUP}/linux-vserver_slackware-${VERSION}.patch
        echo "patch applyed."
        echo
        echo "You can start and enter the virtual server typing: "
        echo
        echo "vserver $NAME start"
        echo "vserver $NAME enter"

else
        echo
        echo "DON'T FORGET to patch /etc/rc.d as follows: "
        echo
        echo "cd ${VDIR}/${NAME}/etc/rc.d"
        echo "patch -p1 < ${SETUP}/linux-vserver_slackware-${VERSION}.patch"
fi

echo
echo "More info at https://notes.sagredo.eu/other-contents-186/slackware-guest-on-linux-vserver-7.html"
echo

Note that /etc/resolv.conf /etc/localtime /etc/profile are copied form the host.

Edit the script inserting at least the NAME, the IP and the CONTEXT. The packages' location should be ok if you downloaded them using my script.

./make_slack_vserver.sh

Apply the patch

The script itsself can install the patch for you. Anyway this is how to apply the patch by yourself:

cd /vservers/vserver_name/etc/rc.d
patch -p1 < /path/to/slack_vserver/slackware-15.0.patch

Inside the tarball you can find the old patch for Slackware 13.1 and 13.37, 14.0, 14.1, 14.2 if you like.

Post installation tasks

Put this inside your rc.local:

/usr/local/etc/init.d/vprocunhide  start

Start the new server

vserver <vserver_name> start
vserver <vserver_name> enter