Multiple Machines

[Karl Vogel]

>> On Fri, 24 Sep 2010 15:04:45 -0800, 
>> David Allen <the.real.david.allen at gmail.com> said:

D> I'm wondering what folks are doing when setting up multiple (more than
D> 1, but less than 10) machines.  Consider, for example, some ordinary
D> files such as the following:
D> /root/.cshrc /home/username/.bashrc

   The first thing I'd recommend for root and home dotfiles is placing them
   under revision control.  I'm (slowly) moving to GIT, but for now RCS
   does the trick just fine:

     me% echo $RCSINIT
     -zLT

     me% ident .vimrc .zshrc
     .vimrc:
          $Revision: 1.40 $
          $Date: 2010-08-16 15:02:52-04 $
          $Source: /home/vogelke/RCS/.vimrc,v $
          $Host: example.org $
          $UUID: a4f4bf9d-514d-37c7-a0e1-04b41434e869 $

     .zshrc:
          $Revision: 1.21 $
          $Date: 2010-09-24 20:13:04-04 $
          $Source: /home/vogelke/RCS/.zshrc,v $
          $Host: example.org $
          $UUID: da56ec7f-14be-39b5-8583-d31b5afb80eb $

   I use the RCSINIT environment variable to prepend "-zLT" to the argument
   list for rcs commands so I get dates in localtime with the timezone
   appended.  A short script called "mkrcs" creates the RCS strings shown
   above; I like including the FQDN of the host on which the file was
   created, along with a random UUID.

   After I get a set of dotfiles I'm happy with, I usually make separate
   tarballs for regular users and root.

D> /etc/fstab /etc/resolv.conf

   /etc files go under revision control with an extra step; just after
   installation, back up /etc.

     root# cd /etc
     root# mkdir /etc.orig
     root# find . -depth -print | pax -rwd -pe /etc.orig

   I also get a signature of all installed files:

     root# cd /
     root# find . -type f -print | grep -v '^./proc/' | sort | xargs md5 -r

   This goes in /root/orig.md5 after stripping out /tmp, /var/tmp, /var/log,
   /var/run, etc.

D> Some files are identical, some require different permissions, and some
D> (like fstab) consist of customizations that need to be added.  Short of
D> enabling root ssh logins or writing makefiles, what would be the best
D> approach to handing the above?

   Any system I maintain gets a directory called "/doc/sitelog/hostname".
   Tarballs, patches, etc. all go under that directory.  If I upgrade a
   system or install a similar one, the tarballs and patches handle most of
   the gruntwork.

   I use a script like the one below to figure out what files I've added to
   (or removed from) /etc and make patches for the modified files.  Patches
   go in their own /tmp/work$$ directory and look like this:

     root# cat /tmp/work81394/etc-shells
     *** /etc.orig/shells    Sun May  7 00:00:23 2006
     --- /etc/shells Wed Sep  9 21:06:04 2009
     ***************
     *** 6,9 ****
     --- 6,13 ----

       /bin/sh
       /bin/csh
     + /bin/ksh
       /bin/tcsh
     + /bin/bash
     + /usr/local/bin/ksh
     + /usr/local/bin/zsh

-- 
Karl Vogel                      I don't speak for the USAF or my company

Hopefully digesting of this tasty post would not cause too much of farting.
            --Yaroslav Halchenko, after reading a good debian-users message

---------------------------------------------------------------------------
#!/bin/sh
#<etc-patches: find modified /etc files

PATH=/usr/local/bin:/usr/local/sbin:/bin:/usr/bin:/sbin:/usr/sbin
export PATH

textfiles () {
    find . -print | xargs file | grep ' text' | cut -f1 -d:
}

flist=/tmp/flist$$
work=/tmp/work$$
mkdir $work || exit 1

( cd /etc && textfiles; cd /etc.orig && textfiles ) |
    cut -c3- | sort -u > $flist

echo "results in $work" >$2
for x in `cat $flist`
do
    cur="/etc/$x"
    orig="/etc.orig/$x"

    if test -f "$cur" -a -f "$orig"; then
        patch=`echo $cur | sed -e 's!^/!!' -e 's!/!-!g'`
        cmp -s $orig $cur || diff -c $orig $cur > $work/$patch
    elif test -f "$cur"; then
        echo ADD: $cur
    elif test -f "$orig"; then
        echo DEL: $cur
    fi
done

rm $flist
exit 0