Create OVS templates

Problem

The rebuild OracleLinux templates for OVS are perfect for a headstart: they have the OVS templates pre-configured. They are perfect, except for one small omission. They have been recently updated with some patches, updating the contents to a newer version then available on the installer (shipping) version. If you don't happen to have an internet connection to the public-yum.oracle.com, nor have a local (mirror) repo, you may find those templates unusable due to missing dependencies. Observe this:

[root@test ~]# yum install gcc
Loaded plugins: security, ulninfo
Setting up Install Process
Resolving Dependencies
--> Running transaction check
---> Package gcc.x86_64 0:4.4.7-16.el6 will be installed
--> Processing Dependency: libgomp = 4.4.7-16.el6 for package: gcc-4.4.7-16.el6.x86_64
--> Processing Dependency: cpp = 4.4.7-16.el6 for package: gcc-4.4.7-16.el6.x86_64
--> Processing Dependency: glibc-devel >= 2.2.90-12 for package: gcc-4.4.7-16.el6.x86_64
--> Processing Dependency: cloog-ppl >= 0.15 for package: gcc-4.4.7-16.el6.x86_64
--> Processing Dependency: libgomp.so.1()(64bit) for package: gcc-4.4.7-16.el6.x86_64
--> Running transaction check
---> Package cloog-ppl.x86_64 0:0.15.7-1.2.el6 will be installed
--> Processing Dependency: libppl_c.so.2()(64bit) for package: cloog-ppl-0.15.7-1.2.el6.x86_64
--> Processing Dependency: libppl.so.7()(64bit) for package: cloog-ppl-0.15.7-1.2.el6.x86_64
---> Package cpp.x86_64 0:4.4.7-16.el6 will be installed
--> Processing Dependency: libmpfr.so.1()(64bit) for package: cpp-4.4.7-16.el6.x86_64
---> Package glibc-devel.x86_64 0:2.12-1.166.el6 will be installed
--> Processing Dependency: glibc-headers = 2.12-1.166.el6 for package: glibc-devel-2.12-1.166.el6.x86_64
--> Processing Dependency: glibc = 2.12-1.166.el6 for package: glibc-devel-2.12-1.166.el6.x86_64
--> Processing Dependency: glibc-headers for package: glibc-devel-2.12-1.166.el6.x86_64
---> Package libgomp.x86_64 0:4.4.7-16.el6 will be installed
--> Running transaction check
---> Package glibc.i686 0:2.12-1.166.el6 will be installed
--> Processing Dependency: glibc-common = 2.12-1.166.el6 for package: glibc-2.12-1.166.el6.i686
--> Processing Dependency: libfreebl3.so(NSSRAWHASH_3.12.3) for package: glibc-2.12-1.166.el6.i686
--> Processing Dependency: libfreebl3.so for package: glibc-2.12-1.166.el6.i686
---> Package glibc-headers.x86_64 0:2.12-1.166.el6 will be installed
--> Processing Dependency: kernel-headers >= 2.2.1 for package: glibc-headers-2.12-1.166.el6.x86_64
--> Processing Dependency: kernel-headers for package: glibc-headers-2.12-1.166.el6.x86_64
---> Package mpfr.x86_64 0:2.4.1-6.el6 will be installed
---> Package ppl.x86_64 0:0.10.2-11.el6 will be installed
--> Running transaction check
---> Package glibc.i686 0:2.12-1.166.el6 will be installed
--> Processing Dependency: glibc-common = 2.12-1.166.el6 for package: glibc-2.12-1.166.el6.i686
---> Package kernel-headers.x86_64 0:2.6.32-573.el6 will be installed
---> Package nss-softokn-freebl.i686 0:3.14.3-22.el6_6 will be installed
--> Finished Dependency Resolution
Error: Package: glibc-2.12-1.166.el6.i686 (local)
           Requires: glibc-common = 2.12-1.166.el6
           Installed: glibc-common-2.12-1.166.el6_7.1.x86_64 (installed)
               glibc-common = 2.12-1.166.el6_7.1
           Available: glibc-common-2.12-1.166.el6.x86_64 (local)
               glibc-common = 2.12-1.166.el6
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
[root@test ~]#

The glib-common has been replaced from the shipping media default 2.12-1.166.el6 to 2.12-1.166.el6_7.1.

Solution

We create our own template, based on the installer media, available to us.

Preparation

Install a default server, having a NIC and a 12G new virtual disk. Using the ISO installer, e.g. we install OL6.7 here.

• Install without configuring a network
• Set timezone to Europe/Amsterdam
• Set a temp root password (anything except empty string)
• Create custom layout
  • 200M /boot partition (force primary)
  • 1G swap partition (force primary)
  • remaining space /root partition (force primary)
• Install bootloader into /dev/xvda
• Install Basic Server

At the end of the install process (after reboot), stop the machine.

Configuration

We now have a disk, which we can mount at any other (existing) machine as an additional disk. On that machine, we can chroot to further prepare the machine.

• Deattach the disk from the default server
• Attach the disk to another (already running/configured) machine

# See it being attached, make note of the disk name, here xvdc: we need the third partition.
dmesg|tail
blkfront: xvdc: flush diskcache: enabled; persistent grants: enabled; indirect descriptors: enabled;
xvdc: xvdc1 xvdc2 xvdc3

Now we can configure this disk.

mydisk=/dev/xvdc3
mymount=/media/mytemplate
myarch=x86_64 # alternative=i386
mypackages="libovmapi libovmapi-devel ovmd python-simplejson xenstoreprovider ovm-template-config  ovm-template-config-authentication ovm-template-config-datetime ovm-template-config-firewall ovm-template-config-network ovm-template-config-selinux ovm-template-config-ssh ovm-template-config-system ovm-template-config-user libovmapi xenstoreprovider ovmd python-simplejson xenstoreprovider oracle-rdbms-server-12cR1-preinstall wget dos2unix zip unzip screen nc expect"
# mount the disks
mkdir -p ${mymount}
mount ${mydisk} ${mymount}
# Add the resolver
echo "search local" > ${mymount}/etc/resolv.conf
echo "nameserver 192.186.2.2" >> ${mymount}/etc/resolv.conf
echo "nameserver 192.186.2.4" >> ${mymount}/etc/resolv.conf
# Change the public-yum to point to public-yum.local
sed -i'' -e's/oracle.com/local/g' ${mymount}/etc/yum.repos.d/public-yum-ol6.repo
# Change root into the disk, using x86_64 architecture, and install software ovm template
chroot ${mymount} /usr/bin/setarch ${myarch} yum --assumeyes --enablerepo=*addons install ${mypackages}
# Disable selinux
sed -i'' -e's/SELINUX=enforcing/SELINUX=disabled/g' ${mymount}/etc/sysconfig/selinux
# Disable iptables
chroot ${mymount} chkconfig iptables off
chroot ${mymount} chkconfig ip6tables off
# Configure the OVM template initial run
sed -i -e's/INITIAL_CONFIG=no/INITIAL_CONFIG=yes/g' ${mymount}/etc/sysconfig/ovmd
# Add user agent12c as example. It makes sense to add the shared key for oracle and root too.
chroot ${mymount} useradd -G dba agent12c
chroot ${mymount} su - agent12c -c "mkdir .ssh;chmod 700 .ssh;touch .ssh/authorized_keys; chmod 700 .ssh/authorized_keys"
echo "ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAqmwDETdBnHx4J1+JHRJsAhgJ+R//+6UsQMSO+ih0yPBn9txv1SaoIwEsYKyakQyx6y4Du1wn3gV68q2xB0p3cP7w+FjGNEXQsZtqlN6qRFvkiWwzce7I1vV8DucpHuySFtVaZlMh/bRAa3etEm3ew/XMX1xuchCFl4jcpigvGcVTxLkCffg5Mcti/6SJvQs8amTB09cVsxgnwbgAu/xAww+w4m+EiwcfgaaHyQxO17qXEee37uLlFaKnurX3UA+qg984UF6N6i4Ijfz53gWcQv1CawFIec8wEBu8Ylb+T2mPwJBdkK+YIe0VBVx9hbEFtPYz4n2fTSPxyVRnyptxPw== agent12c@spc.local" >> ${mymount}/home/agent12c/.ssh/authorized_keys
# Add agent12c to sudoers
echo "" >> ${mymount}/etc/sudoers
echo "agent12c ALL=(ALL) NOPASSWD:ALL" >> ${mymount}/etc/sudoers
# Disable tty requirement
sed -i'' -e's/^Defaults\ \ \ \ requiretty/#\0/g' ${mymount}/etc/sudoers
# Clear settings
chroot ${mymount} /usr/bin/setarch ${myarch} yum clean all
rm -fR ${mymount}/tmp/*
rm -fR ${mymount}/root/.bash_history
# unmount the disks
umount ${mymount}
rmdir ${mymount}

Finalizing

All we now have to do, is create a OVS template of the disk.

• Deattach the disk from the running/configured machine
• Reattach it the default machine
• Create a new OVM template, based on the default machine