Difference between revisions of "ExecuteInAllVEs"

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I found myself often faced with a need to run the same command in all VEs, e.g. ''apachectl restart'' to restart all webservers or ''dmesg | tail'' to see the latest news from everybody.
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You can loop through all VEs and execute this this easily:
 
<code>
 
<code>
#!/bin/bash
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  for veid in `vzlist -Hoveid`; do vzctl exec $veid COMMAND; done
CONFDIR="/etc/vz/conf"
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</code>
if [ "$1" == "" ]; then
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  echo "$0 -- Execute a command on all VEs"
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Knowing this, you can also save some typing later by making a simple utility out of it.
  echo ""
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I like to call this ''/usr/sbin/vzexec'' so I can later just say ''vzexec apachectl restart''
  echo "Example: vzexec service httpd restart"
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<code>
  echo ""
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  #!/bin/bash
  echo "Note that variables are expanded in the host's shell, and use '' to prevent this."
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  # vzexec -- execute a command on all VEs
  echo "Example:  vzexec echo \$PWD    and  vzexec 'echo \$PWD'  are different."
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  if [ "$1" == "" ]; then
  exit
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    echo "$0 -- Execute a command on all VEs"
fi
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    echo ""
for veconf in $CONFDIR/*.conf ; do
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    echo "Example: vzexec service httpd restart"
  veid=`basename $veconf .conf`
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    echo ""
  if [ "$veid" == "0" ]; then continue; fi
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    echo "Note that variables are expanded in the host's shell, and use ' ' to prevent this."
  vename=`grep ^NAME $veconf | head -1 | sed -e 's@NAME=@@' | sed -e 's@"@@g'`
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    echo "Example:  vzexec echo \$PWD    and  vzexec 'echo \$PWD'  are different."
  echo "*** VE $veid ($vename)"
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    exit
  vzctl exec $veid $@
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  fi
done
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  for veid in `vzlist -Hoveid`; do
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    echo "*** VE $veid"
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    vzctl exec $veid $@
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  done
 
</code>
 
</code>

Latest revision as of 15:23, 6 January 2008

I found myself often faced with a need to run the same command in all VEs, e.g. apachectl restart to restart all webservers or dmesg | tail to see the latest news from everybody.

You can loop through all VEs and execute this this easily:

 for veid in `vzlist -Hoveid`; do vzctl exec $veid COMMAND; done 

Knowing this, you can also save some typing later by making a simple utility out of it. I like to call this /usr/sbin/vzexec so I can later just say vzexec apachectl restart

 #!/bin/bash
 # vzexec -- execute a command on all VEs
 if [ "$1" == "" ]; then
   echo "$0 -- Execute a command on all VEs"
   echo ""
   echo "Example: vzexec service httpd restart"
   echo ""
   echo "Note that variables are expanded in the host's shell, and use ' ' to prevent this."
   echo "Example:   vzexec echo \$PWD    and   vzexec 'echo \$PWD'   are different."
   exit
 fi
 for veid in `vzlist -Hoveid`; do
   echo "*** VE $veid"
   vzctl exec $veid $@
 done