Installing MySQL in Solaris 10 zones / containers

Now that installing MySQL in Solaris zones is even officially supported by the MySQL support group (see http://www.mysql.com/about/legal/supportpolicies/policies-06.html#q03), the question is: What is the right way of installing MySQL in a zone. Of course this depends on what you want to achieve. The following description is based on Solaris 10. On Opensolaris this is different (somewhat easier, as there are no more sparse root zones.)

If you run a local zone as a whole root zone, you can easily install MySQL from tarball or the package installer.

If you run a local zone as a sparse root zone, there are different options:

First you cannot use the package installer, as this procedure will copy binaries to /usr/bin. But /usr/bin is inherited from the global zone and write protected. You have to use the tarball installation.

1. Make /usr/local/mysql writable
The tar ball will install in /usr/local/mysql. You can create a symbolic link in your GLOBAL ZONE:
> ln -s /localsoftware/mysql  /usr/local/mysql
This link points to a directory, that is not inherited. So in every zone /usr/local/mysql will point to a dedicated directory with write permission. You untar the software in the zone in /localsoftware

2. Make /usr/local writable
If you want no software from /usr/local in the global zone to be available in the local zones as well, you can use solution#1 even with /usr/local. So in every zone, /usr is inherited and write protected. But /usr/local points to a directory, that is writable. This is my personal favorit:

In the global zone:

> mv /usr/local /LOCAL
> ln -s /LOCAL /usr/local
and in the local zone
> mkdir /LOCAL
> cd /usr/local
> gtar -xzf /anywhere/mysql.tgz

3. Install in different location
You can untar the MySQL tarball in any other location, that is not inherited from the global zone. Maybe /opt/ ? Check with mount, what directories are loopback mounted from the global zone with read-only flag.

4. Install MySQL globally for all zones
You can untar MySQL in the global zone's /usr/local. Then every local zone has a MySQL installation as well. But then it is important, that all write access in MySQL is done to a writable directory, like /var/lib/mysql. Otherwise MySQL in the local zone will stop, because it cannot write it's logfile/errorfile/datafiles in /usr/local/mysql/data

Cloning zones

THIS BLOG POST GIVES WRONG ADVICE. DON'T DO THIS!

As the zones use ZFS as root filesystem it's easy to do a zfs snapshot/clone to reproduce a zone. The different zones have only one difference: They differ in /etc/nodename, they have different rootpaths and they have different IP addresses.

I wrote a script to read from global's /etc/hosts the ip address. Zonerootpath is /zones/zonename and /etc/nodename must contain as well. The name of the zone is always identical to the hostname of the zone. That rule is not from OpenSolaris but from me.  ;-)

Here is my script: Beware: I hate to do a lot of checking. This is not for general use...

#!/bin/bash
echo "Creating zone $1 from zone TEMPLATE"
echo check if $1 does not already exist...
zoneadm list -cv | grep $1 && exit -1

echo -n "Retrieving TEMPLATE's IP: "
TEMPLATE_IP=$(grep TEMPLATE /etc/hosts | nawk '{print $1}')
echo $TEMPLATE_IP
echo -n "Retrieving $1's IP: "
NEW_IP=$(grep $1 /etc/hosts | nawk '{print $1}')
echo $NEW_IP

echo "Creating Command File"
rm /tmp/MBcommand 2> /dev/null

# We use the config of TEMPLATE zone and modify this
zonecfg -z TEMPLATE export | sed s/TEMPLATE/$1/ | sed s/$TEMPLATE_IP/$NEW_IP/ > /tmp/MBcommand

echo "generating new zone"
zonecfg -z $1 -f /tmp/MBcommand
echo "Installing new zone as snapshot"
zoneadm -z $1 clone TEMPLATE
echo done.

Very easy so far.

zoneadm clone will do a sys-unconfig to remove any network configuration from the clone. Acutally I don't like that. I don't want to run the whole sysidcfg configuration with every clone. So I did a hack:

AND HERE BEGINS MY PROBLEM. sys-unconfig IS NECESSARY FOR THE HOSTID. 

/usr/lib/brand/ipkg/clone is the shell script that will run, when you do a 'zoneadm clone'.

And here is the (malicious) call to /usr/sbin/sys-unconfig. I removed this and changed it to only write the new /etc/nodename file in the zone's root filesystem. Here are the last few lines of /usr/lib/brand/ipkg/clone:

/usr/sbin/mount -F zfs $zpds/$zpname/ROOT/$BENAME $zonepath/root || \
fail_incomplete "$f_zfs_mount"

#/usr/sbin/sys-unconfig -R $zonepath/root || fail_incomplete "$f_sysunconfig"
echo $zonename > $zonepath/root/etc/nodename
echo Run /usr/sbin/sys-unconfig manually. Command removed by Mario in $0
echo Instead edited only the /etc/nodename file with $zonename

/usr/sbin/umount $zonepath/root || fail_fatal "$f_umount"

exit $ZONE_SUBPROC_OK

Now I only have to populate /etc/hosts with my machines and run one command to have a completely installed and configured zone for my demo environment:

root@ap-mysql:~# ./create_zone_from_TEMPLATE berlin
Creating zone berlin from zone TEMPLATE
check if berlin does not already exist...
Retrieving TEMPLATE's IP:
Retrieving berlin's IP: 192.168.14.226
Creating Command File
generating new zone
Installing new zone as snapshot
Run /usr/sbin/sys-unconfig manually. Command removed by Mario in /usr/lib/brand/ipkg/clone
Instead only the /etc/nodename edited with berlin
done.

Creating a datacenter in one Solaris machine

There is a big event coming: Cebit!

And with that I took the task to implement a demo for MySQL Enterprise Monitor to show at the Sun booth. So I need a machine for the enterprise monitor and some machines to run MySQL databases. After all I need something to monitor.

So the setup will be an Ultra 24 desktop machine installed with OpenSolaris 2008.11 . For every machine I will install a zone to run a separate database and one zone to run the enterprise monitor.

So here is my first round of experiences: Installing a template container on OpenSolaris and cloning it to build four or five separate database machines. Let's go:

####################################################################################
# Creating ZFS filesystems for all zone root-fs and a zfs that's shared between global and all local zones for easy data exchange
####################################################################################

root@ap-mysql:/# zfs create -o mountpoint=/zones rpool/zones
root@ap-mysql:/# zfs create -o mountpoint=/zones/share rpool/zones/share

####################################################################################
# Create a template zone, that will be cloned for all demo zones
####################################################################################

root@ap-mysql:/# zonecfg -z TEMPLATE
TEMPLATE: No such zone configured
Use 'create' to begin configuring a new zone.
zonecfg:TEMPLATE> create
zonecfg:TEMPLATE> set zonepath=/zones/TEMPLATE
zonecfg:TEMPLATE> add inherit-pkg-dir
zonecfg:TEMPLATE:inherit-pkg-dir> set dir=/zones/share
zonecfg:TEMPLATE:inherit-pkg-dir> end
zonecfg:TEMPLATE> add net
zonecfg:TEMPLATE:net> set physical=e1000g0
zonecfg:TEMPLATE:net> set address=192.168.14.225/24
zonecfg:TEMPLATE:net> end
zonecfg:TEMPLATE> verify
zonecfg:TEMPLATE> commit
zonecfg:TEMPLATE> exit
root@ap-mysql:/# zoneadm list -cv
ID NAME STATUS PATH BRAND IP
0 global running / native shared
- TEMPLATE configured /zones/TEMPLATE ipkg shared

####################################################################################
# Now we have the TEMPLATE zone. Next step is to install the zone and boot it.
# CAVEAT: The machine needs internet access to install a zone. The software respository must be www.opensolaris.org in the moment... :-(
####################################################################################

root@ap-mysql:/# zoneadm -z TEMPLATE install
A ZFS file system has been created for this zone.
Authority: Using http://pkg.opensolaris.org/release/.
Image: Preparing at /zones/TEMPLATE/root ... done.
Installing: (output follows)
DOWNLOAD PKGS FILES XFER (MB)
Completed 52/52 7862/7862 72.41/72.41

PHASE ACTIONS
Install Phase 12939/12939
PHASE ITEMS
Reading Existing Index 9/9
Indexing Packages 52/52

Note: Man pages can be obtained by installing SUNWman
Postinstall: Copying SMF seed repository ... done.
Postinstall: Working around http://defect.opensolaris.org/bz/show_bug.cgi?id=741
Done: Installation completed in 518.993 seconds.

Next Steps: Boot the zone, then log into the zone console
(zlogin -C) to complete the configuration process


####################################################################################
# time to boot the zone
# prepare a second terminal window and start the zone's console with
# zlogin -C TEMPLATE
####################################################################################

root@ap-mysql:~# zoneadm -z TEMPLATE boot

####################################################################################
# In TEMPLATE's console, do the interactive sysidcfg procedure
# I like to install some other packages. The default set is too small for me
# Adding packages is easy: 'pkg install SUNWxyz'. Unfortunately you have to
# be in the internet to have access to www.opensolaris.org
# hopefully this will change in the future.

# Here is the list of packages I installed for the showcase:

# SUNWgnu-coreutils

# SUNWgcmn

# SUNWgtar    needed for installing MySQL tarball

# SUNWuiu8

# SUNWman    can't live without it

# SUNWless

# SUNWpkgcmds   to use pkgadd later with MySQL
####################################################################################

That's it. We have a zone called TEMPLATE. Next blog will be cloning to define 4 identical machines.