mysql8.4/mysqld-wait-ready
2024-02-05 16:59:12 +01:00

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#!/bin/sh
# This script waits for mysqld to be ready to accept connections
# (which can be many seconds or even minutes after launch, if there's
# a lot of crash-recovery work to do).
# Running this as ExecStartPost is useful so that services declared as
# "After mysqld" won't be started until the database is really ready.
# Service file passes us the daemon's PID
daemon_pid="$1"
# extract value of a MySQL option from config files
# Usage: get_mysql_option SECTION VARNAME DEFAULT
# result is returned in $result
# We use my_print_defaults which prints all options from multiple files,
# with the more specific ones later; hence take the last match.
get_mysql_option(){
result=`/usr/bin/my_print_defaults "$1" | sed -n "s/^--$2=//p" | tail -n 1`
if [ -z "$result" ]; then
# not found, use default
result="$3"
fi
}
# Defaults here had better match what mysqld_safe will default to
get_mysql_option mysqld datadir "/var/lib/mysql"
datadir="$result"
get_mysql_option mysqld socket "$datadir/mysql.sock"
socketfile="$result"
# Wait for the server to come up or for the mysqld process to disappear
ret=0
while /bin/true; do
RESPONSE=`/usr/bin/mysqladmin --socket="$socketfile" --user=UNKNOWN_MYSQL_USER ping 2>&1`
mret=$?
if [ $mret -eq 0 ]; then
break
fi
# exit codes 1, 11 (EXIT_CANNOT_CONNECT_TO_SERVICE) are expected,
# anything else suggests a configuration error
if [ $mret -ne 1 -a $mret -ne 11 ]; then
ret=1
break
fi
# "Access denied" also means the server is alive
echo "$RESPONSE" | grep -q "Access denied for user" && break
# Check process still exists
if ! /bin/kill -0 $daemon_pid 2>/dev/null; then
ret=1
break
fi
sleep 1
done
exit $ret