Wednesday, April 15, 2009

Lessons with OpenSolaris Appliances

Going through the comments for Minimal OpenSolaris Appliance entry,  I thought I will go over the problems I encountered when I was working on the create_solaris_appliance.sh script and what I think we can do to improve OpenSolaris in those areas.


1. Setting up the disk


This is probably the first thing that most appliance creators will have to do is to format a new media before it is usable by OpenSolaris. Now to make a disk usable by OpenSolaris (on x86/x64 platforms) two things needs to be done, one a primary Solaris partition needs to be created using fdisk and then a regular Solaris VTOC needs to be initialized on the Solaris partition. While the experience is bit easier with the interactive option of the commands, putting it in a script can be challenging.


Fortunately fdisk has -B option. From the man page:



    -B
Default to one Solaris partition that uses the whole
disk. On an x86 machine, if the disk is larger than 2 TB
(terabytes), the default size of the Solaris partition
will be limited to 2 TB.


Hence I could use the following easily in my script:


fdisk -n -B /dev/rdsk/${INSTALLDISK}p0


Unfortunately I saw no such option for fmthard. Infact it made it more difficult since you need to enter the geometry information of the target disk. I took the easy way out by finding the same for the default VirtualBox disk size which is 16GB and using it as follows:


fmthard -d 0:2:00:48195:33447330 /dev/rdsk/${INSTALLDISK}p0

There are some scripting ways to work this around as Vikram Datta commented on my earlier entry:



  SecCnt=`prtvtoc /dev/rdsk/${INSTALLDISK}p0 | awk '/sectors\/cylinder/ { print $2 }'`
LastSect=`prtvtoc /dev/rdsk/${INSTALLDISK}p0 | awk '$1 == "2" { print $5 }'`
LastSect=`expr $LastSect - $SecCnt`
fmthard -d 0:2:00:${SecCnt}:${LastSect} /dev/rdsk/${INSTALLDISK}p0


But I think it should be as easy as  fdisk.. i.e. doing the following:


fmthard -B /dev/rdsk/${INSTALLDISK}p0

Hence I have filed a new RFE 6829475. I think this RFE is useful not just for my script but in general helps improve usability of the command to a new learner of OpenSolaris.


2. Setting up the ZPool


The next step of creating zpool for the root device was pretty straight forward


zpool create -f rpool ${INSTALLDISK}s0
zfs set compression=on rpool
zfs create -o mountpoint=legacy rpool/ROOT
zfs create -o mountpoint=$PKG_IMAGE rpool/ROOT/VOSApp
zfs create -V 128M rpool/swap
zfs create -V 16M rpool/dump
zfs create rpool/ROOT/VOSApp/opt
zfs create rpool/ROOT/VOSApp/var
zfs create rpool/export
zpool set bootfs=rpool/ROOT/VOSApp rpool

Here I took liberty of separating out /opt /var into separate dataset so that I can enable zfs snapshots just for "optional" and "variable" data of the applications. This is a point of view of deployment. Your view may be different here.


3. Setting up the packages from OpenSolaris repository


The next step on how to use OpenSolaris repository to install the pacakges. Alex Eremin had great pointers on his blog that I adapted . The initial setup can be easily done by exporting the PKG_IMAGE environment variable to the directory where you are currently mounting the zpool and then using pkg image-create command.


pkg image-create -f -F -a opensolaris.org=http://pkg.opensolaris.org/release $PKG_IMAGE
pkg refresh

Then  I played with the package list over and over again to get a minimal size with most network adapter drivers to get on the internet and all required pacakges to allow "pkg" command to work. Of course this is the piece that took me quite a bit of trial and error to figure out the right mix of pacakges so OpenSolaris does boot up successfully and allow "pkg" to run successfully.


pkg install SUNWcsd
pkg install SUNWcs
pkg install SUNWcar SUNWcakr SUNWkvm SUNWos86r SUNWrmodr \
SUNWpsdcr SUNWpsdir SUNWcnetr SUNWesu SUNWkey SUNWnfsckr \
SUNWnfsc SUNWgss SUNWgssc SUNWbip SUNWbash SUNWloc SUNWsshcu \
SUNWsshd SUNWssh SUNWtoo SUNWzfskr SUNWipf SUNWintgige SUNWipkg \
SUNWadmr SUNWadmap SUNWPython SUNWperl584core SUNWgrub SUNWxcu6\
SUNWxcu4 SUNWgawk SUNWgtar SUNWgnu-coreutils SUNWscp SUNWfmd \
SUNWxge SUNWbge SUNWnge SUNWrge SUNWrtls \
SUNWixgb SUNWchxge SUNWzfs-auto-snapshot SUNWsolnm

I did realize one thing.. Loading one package at a time with pkg is awfully slow. By putting all the packages within one line (except for SUNWcsd and SUNWcs) I could cut down the time from hours to minutes. This was my "Eureka" moment when I could install the packages to a bare-metal .. well a bare-virtualbox VDI within 10 minutes.


4. Setting up the SMF Database on the system


cp $PKG_IMAGE/lib/svc/seed/global.db $PKG_IMAGE/etc/svc/repository.db
chmod 0600 $PKG_IMAGE/etc/svc/repository.db
chown root:sys $PKG_IMAGE/etc/svc/repository.db

# setup smf profiles
ln -s ns_files.xml $PKG_IMAGE/var/svc/profile/name_service.xml
ln -s generic_limited_net.xml $PKG_IMAGE/var/svc/profile/generic.xml
ln -s inetd_generic.xml $PKG_IMAGE/var/svc/profile/inetd_services.xml
ln -s platform_none.xml $PKG_IMAGE/var/svc/profile/platform.xml
# Set the environment variables for svccfg.
SVCCFG_DTD=${PKG_IMAGE}/usr/share/lib/xml/dtd/service_bundle.dtd.1
SVCCFG_REPOSITORY=${PKG_IMAGE}/etc/svc/repository.db
SVCCFG=/usr/sbin/svccfg
export SVCCFG_DTD SVCCFG_REPOSITORY SVCCFG

${SVCCFG} import ${PKG_IMAGE}/var/svc/manifest/milestone/sysconfig.xml

Again this is one area I think OpenSolaris can improve a bit. It does some amount of research (google, Alex Eremin) before understanding how to set it up properly. (But then I am not a kernel engineer.)



5. Other Miscellaneous but important stuff to get a bootable system


The following are basically hacks in some ways to get to a bootable system. 


# Set TimeZone
echo "$TIMEZONE" >⁞ $PKG_IMAGE/etc/TIMEZONE
echo $HOSTNAME > $PKG_IMAGE/etc/nodename

# configure our new /etc/vfstab
printf "rpool/ROOT/VOSApp -\t/\t\tzfs\t-\tno\t-\n" >> $PKG_IMAGE/etc/vfstab
printf "/dev/zvol/dsk/rpool/swap\t-\t-\t\tswap\t-\tno\t-\n" >> $PKG_IMAGE/etc/vfstab
chmod a+r $PKG_IMAGE/etc/vfstab

# turn off root as a role
printf "/^root::::type=role;\ns/^root::::type=role;/root::::/\nw" |\
ed -s $PKG_IMAGE/etc/user_attr
# Edit etc/ssh/sshd_config to allow ssh to root account
printf "/^PermitRootLogin no\ns/^PermitRootLogin no/PermitRootLogin yes/\nw" |\
ed -s ${PKG_IMAGE}/etc/ssh/sshd_config

# Generate ssh keys
ssh-keygen -t dsa -f $PKG_IMAGE/etc/ssh/ssh_host_dsa_key -N ''
ssh-keygen -t rsa -f $PKG_IMAGE/etc/ssh/ssh_host_rsa_key -N ''



6. Finally the boot archive and  grub


# configure /dev in the new image
devfsadm -R $PKG_IMAGE
bootadm update-archive -R $PKG_IMAGE
$PKG_IMAGE/boot/solaris/bin/update_grub -R $PKG_IMAGE
# For zfs root, menu.lst has moved to /rpool/boot/grub/menu.lst. #
# create the new real grub menu
cat <⁞<-EOF > /rpool/boot/grub/menu.lst
default 0
timeout 10
splashimage /boot/grub/splash.xpm.gz
title  Appliance based on OpenSolaris 2008.11
findroot (pool_rpool,0,a)
bootfs rpool/ROOT/VOSApp
kernel\$ /platform/i86pc/kernel/\$ISADIR/unix  -B \$ZFS-BOOTFS
module\$ /platform/i86pc/\$ISADIR/boot_archive
EOF
# make the grub menu files readable by everyone.
chmod a+r $PKG_IMAGE/boot/grub/menu.lst
chmod a+r /rpool/boot/grub/menu.lst
# setup /etc/bootsign so that grub can find this zpool
dir -p /rpool/etc>
echo pool_rpool > /rpool/etc/bootsign
zfs set mountpoint=/ rpool/ROOT/VOSApp
zfs set compression=off rpool



Hope this makes it easier for  someone thinking of making their own appliances based on OpenSolaris.


NOTE: There was fair number of people who did download the images. I did accidently lose the OpenSolaris image once after it was downloaded 75 times.  But you can track the images directly at mediacast.sun.com/tags/appliance






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