[359] | 1 | #!/bin/bash |
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| 2 | |
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| 3 | CRONROOT=/afs/athena.mit.edu/contrib/scripts/cron |
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| 4 | |
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| 5 | # Find our real hostname |
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| 6 | |
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| 7 | # This big long mess just results in a list of ip/name. |
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| 8 | for i in `/sbin/ip addr show dev eth0 | grep ' inet ' | cut -f 6 -d ' ' | cut -f 1 -d '/' | xargs -n 1 host | cut -f 1,5 -d ' ' | sed 'y/ /\//'`; do |
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| 9 | hostip=`echo $i | cut -f 1 -d '.'` |
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| 10 | name=`echo $i | cut -f 2 -d '/'` |
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| 11 | case $name in |
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| 12 | SCRIPTS*) echo "$name";; |
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| 13 | *) echo "Heartbeat for $name ($hostip)"; HOSTNAME=$name; HOSTIP=$hostip;; |
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| 14 | esac; |
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| 15 | done |
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| 16 | |
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| 17 | # Tell everyone who's watching that we're alive |
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| 18 | touch $CRONROOT/servers/$HOSTNAME |
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| 19 | |
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| 20 | # Sleep based on our IP, in an attempt to not collide with another server also trying to gain control of the mirroring |
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| 21 | sleep $(($HOSTIP - 50)) |
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| 22 | |
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| 23 | # Find the current master |
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| 24 | MASTER="DOES-NOT-EXIST" |
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| 25 | current_server () { |
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| 26 | for i in $CRONROOT/server-crontabs/*; do |
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| 27 | if [ -h $i ]; then |
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| 28 | MASTER=`basename $i` |
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| 29 | echo "Current master $MASTER" |
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| 30 | fi |
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| 31 | done |
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| 32 | } |
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| 33 | if lockfile -1 -r10 -l90 $CRONROOT/lock/heartbeat.lock; then |
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| 34 | current_server |
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| 35 | |
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| 36 | # The only way to compare times in bash is to compare the modtimes of two files. |
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| 37 | compare=`mktemp /tmp/heartbeat-compare.XXXXXXXXXX` |
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| 38 | touch -d '2 minutes ago' $compare |
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| 39 | |
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| 40 | if [[ $CRONROOT/servers/$MASTER -ot $compare ]]; then |
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| 41 | # Master died! Take over. |
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| 42 | echo "Master '$MASTER' died! Taking over." |
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| 43 | for i in $CRONROOT/server-crontabs/*; do |
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| 44 | if [ -h $i ]; then |
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| 45 | echo rm $i |
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| 46 | rm $i |
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| 47 | else |
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| 48 | echo rmdir $i |
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| 49 | rmdir $i |
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| 50 | fi |
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| 51 | done |
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| 52 | for i in $CRONROOT/servers/*; do |
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| 53 | server=`basename $i` |
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| 54 | case $server in |
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| 55 | $HOSTNAME) |
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| 56 | echo ln -s ../crontabs/ $CRONROOT/server-crontabs/$HOSTNAME |
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| 57 | ln -s ../crontabs/ $CRONROOT/server-crontabs/$HOSTNAME;; |
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| 58 | *) |
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| 59 | echo mkdir $CRONROOT/server-crontabs/$server |
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| 60 | mkdir $CRONROOT/server-crontabs/$server;; |
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| 61 | esac; |
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| 62 | done; |
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| 63 | fi |
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| 64 | |
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| 65 | rm $compare |
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| 66 | rm -f $CRONROOT/lock/heartbeat.lock |
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| 67 | fi |
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