Quest: creating one hundred zones

Well, I need to create about one hundred zones once again. You could probably use ansible for this, but an old-fashioned man will do everything in shell. So: we have one "golden image" and have to create 100 zones like it. We could clone it, but with clones you receive wonderful issue - beadm activate fails in zone. So we create zones and do send/receive manually. This looks like this:

#!/bin/bash
set -e

for i in $(seq 1 100); do 

    #Creating interface for the zone
    dladm create-vnic -l e1000g1 hnet$i

    #Creating initial config   

    TEMPFILE=$(mktemp /tmp/XXXXXXXXXXXXXXXXXX)
    cat > $TEMPFILE <<EOF
create -b
set zonepath=/zones/h$i
set autoboot=true
set ip-type=exclusive
add net
set physical=hnet$i
end
add capped-memory
set physical=2G
end
add rctl
set name=zone.max-swap
add value (priv=privileged,limit=2147483648,action=deny)
end
add rctl
set name=zone.max-locked-memory
add value (priv=privileged,limit=536870912,action=deny)
end
EOF

    zonecfg -z h$i -f $TEMPFILE
    zfs send -R data/zones/h0@initial | zfs recv -F data/zones/h$i
 
    # Zone tools should know that zone is in installed state, not configured
    # Also during installation zoneadm assigns uuid to zone (last field). We do this manually.
    uuid=$(uuidgen)
    gsed -i  -e "/^h${i}:/ s/\$/${uuid}/" -e "/^h${i}:/ s/configured/installed/" /etc/zones/index
    zoneadm -z h$i mount

    # We known that golden image ip address  ends in 254 and change it
    addr=$((1+$i))
    sed -i -e "s:hnet0:hnet$i:g" -e "s:\.254:.$addr:g" /zones/h$i/root/etc/ipadm/ipadm.conf
    zoneadm -z h$i unmount
    zfs destroy data/zones/h$i@initial
    rm $TEMPFILE
    zoneadm -z h$i boot
done

Does ip belong to network?

It's so easy to check if IP belong to network... Until you start doing this in shell. I've tried and finally got this. This version works in bash, dash and ksh... Good enough for me, but perhaps it could be optimized a bit to avoid cut usage. Our function gets two parameters - ip address and network in address/netmask format. In fact we compare IPaddress & netmask and IPnetwork & netmask.

#!/bin/sh

belongs_network ()
{
   addr=$1
   network=$2

   netaddr=`echo $network | cut -d / -f 1`
   netcdr=`echo $network | cut -d / -f 2`

   a1=$(echo "$addr" | cut -d . -f 1)
   a2=$(echo "$addr" | cut -d . -f 2)
   a3=$(echo "$addr" | cut -d . -f 3)
   a4=$(echo "$addr" | cut -d . -f 4)

   n1=$(echo "$netaddr" | cut -d . -f 1)
   n2=$(echo "$netaddr" | cut -d . -f 2)
   n3=$(echo "$netaddr" | cut -d . -f 3)
   n4=$(echo "$netaddr" | cut -d . -f 4)

   ares=$((($a1*256*256*256+$a2*256*256+$a3*256+$a4)>>(32-$netcdr)))
   nres=$((($n1*256*256*256+$n2*256*256+$n3*256+$n4)>>(32-$netcdr)))

   if [ $ares -eq $nres ] ; then
     return 0
   else
     return 1
   fi
}

if belongs_network 10.208.103.255 10.208.128.0/17; then
  echo "belongs"
else 
  echo "does not belong"
fi

elfdump -a in Solaris

Solaris userland is rather specific... A lot of utilities misses convenient options from GNU/BSD analogs. E.g., we don't have "elfdump -a" here... As always, a bit of scripting solves this problem:

elfdump -c /bin/ls |grep Header |awk ' { print $4; }'  |xargs -n 1 -I '{}' elfdump -N '{}' /bin/ls 

POSIX rules, bashism sux, and shell is a great tool...

Just one link. Here I found a lot of useful advices and tricks concerning writing scripts in POSIX shell. As I'm really fond of shell, I'd like to share this link...