Shell Script Consolidation
If you were to look under the 'hood', you will realise that S1WS start/stop scripts actually make use of a utililty called 'parsexml' to get information related to it's instance. 'parsexml' is located at $INSTALL_DIR/lib/parsexml, but there isn't any documentation on how to use it. Thanks to the UNIX utility - strings, basically it prints the strings of printable characters in file. By 'strings' the parsexml file, we discovered the usage and it's corresponding variables name. So, to find out the PID of the web instance, you need to display the content in the PID_FILE: $INSTALL_DIR/lib/parsexml -g PID_FILE
#$INSTALL_DIR/parsexml -h failure: CONF1115: Error opening -h/server.xml (File not found) #$INSTALL_DIR//parsexml --help failure: CONF1115: Error opening --help/server.xml (File not found) #$INSTALL_DIR/parsexml Usage: parsexml path -g option parsexml path #strings $INSTALL_DIR/lib/parsexml ... Usage: parsexml path -g option parsexml path server.xml SERVER_PID_FILE SERVER_TEMP_DIR SERVER_USER SERVER_PLATFORM_SUBDIR SERVER_JVM_LIBPATH %s: invalid option Options: PID_FILE TEMP_DIR USER JVM_LIBPATH PLATFORM_SUBDIR ... #$INSTALL_DIR/lib/parsexml -g PID_FILE /tmp/https-chihungchan.blogspot.com-9d93b4d6-1/pid #cat /tmp/https-chihungchan.blogspot.com-9d93b4d6-1/pid 5266
Since all these scripts are similar, we should be able to 'considerate' them together to a single generic script (I called it s1ws.sh). By doing so, we need to supply the script with the instance name. However, the instance name can be pretty long and it would not be user-friendly if you were to ask the user to supply that every time he/she needs to run it. I cannot remember where I came across the auto-complete trick in bash shell, but basically it allows you to auto-complete the name of the file/directory in your current working directory. In our case, we cannot limit the user from running our script (s1ws.sh) from the $INSTALL_DIR directory. The trick is to run some unix commands (ls -1d ... | sed ...) to extract the instance names and supply that to the 'complete' command which is a bash shell builtin command.
_COMP=($(ls -1d /opt/SUNWwbsvr/admin-server /opt/SUNWwbsvr/https-* | sed 's#.*/##'))
complete -o default -W "${_COMP[*]}" s1ws.sh
In the s1ws.sh script, it allows user to query the status of the web instance. Status includes process id, process name and arguments, listening port and it's corresponding netstat LISTENing output. It is possible to get hold of listening port number from the '$INSTALL_DIR/$INSTANCE/config/server.xml'. With xml_grep command in Linux, you can extract the port number by using
XPath notation. In our case, the XPath will be /server/http-listener/port. Here is a snippet of the server.xml
<server>
...
<http-listener>
<name>http-listener-1</name>
<ip>192.168.1.2</ip>
<port>80</port>
<server-name>chihungchan.blogspot.com</server-name>
<default-virtual-server-name>chihungchan.blogspot.com</default-virtual-server-name>
</http-listener>
...
</server>
Here is the generic "s1ws.sh":
#! /bin/sh
INSTALL_DIR="/opt/SUNWwbsvr"
if [ ! -d "$INSTALL_DIR" ]; then
echo "Error: \"$INSTALL_DIR\" directory does not exist"
exit 1
fi
PARSEXML="$INSTALL_DIR/lib/parsexml"
usage()
{
echo "Usage: $0 <instance> <start|stop|status>"
echo ""
}
if [ $# -ne 2 ]; then
usage
exit 1
fi
INSTANCE="$1"
ACTION="$2"
isRunning()
{
IS_RUNNING=0
CONFIG_DIR="$INSTALL_DIR/$INSTANCE/config"
if [ -d "$CONFIG_DIR" ]; then
PID_FILE=`$PARSEXML "$CONFIG_DIR" -g PID_FILE`
if [ -f "$PID_FILE" ]; then
PID=`cat "$PID_FILE"`
else
echo "***WARNING*** Web instance \"$INSTANCE\" is not running"
return
fi
else
echo "***ERROR*** Web instance \"$INSTANCE\" does not contain any configuration file"
return
fi
#
# check if process exist, via /proc
#
if [ -d /proc/$PID ]; then
IS_RUNNING=1
if [ $VERBOSE == 1 ]; then
echo "Process ID: $PID"
echo -e "`cat /proc/$PID/cmdline | tr '\000' ' '`\n"
# listen to port
port=`xml_grep --cond /server/http-listener/port --text_only $INSTALL_DIR/$INSTANCE/config/server.xml`
echo "Listening at port: $port"
netstat -an | awk '$6 == "LISTEN" && $4 ~/:'$port'$/{print}'
fi
fi
}
VERBOSE=0
case "$ACTION" in
status)
VERBOSE=1
isRunning
if [ "$IS_RUNNING" -eq 0 ]; then
exit 1
else
exit 0
fi
;;
start)
isRunning
if [ "$IS_RUNNING" -eq 1 ]; then
echo "***WARNING*** Web instance \"$INSTANCE\" is still running. No need to start"
else
$INSTALL_DIR/$INSTANCE/bin/startserv
isRunning
if [ "$IS_RUNNING" -eq 1 ]; then
echo "***INFO**** Successfully started."
fi
fi
;;
stop)
isRunning
if [ "$IS_RUNNING" -eq 0 ]; then
echo "***WARNING*** Web instance \"$INSTANCE\" is stopped. No need to stop"
else
$INSTALL_DIR/$INSTANCE/bin/stopserv
isRunning
if [ "$IS_RUNNING" -eq 0 ]; then
echo "***INFO**** Successfully stopped."
fi
fi
;;
*)
usage
exit 1
;;
esac
and "s1ws.sh" in action:
#s1ws.sh Usage: /usr/local/bin/s1ws.sh <instance> <start|stop|status> #s1ws.sh <tab> admin-server https-chihungchan.blogspot.com https-chihungchan.blogspot.com-dev1 https-chihungchan.blogspot.com-dev2 https-chihungchan.blogspot.com-test1 https-chihungchan.blogspot.com-test2 https-chihungchan.blogspot.com-uat #s1ws.sh admin-server status Process ID: 7215 webservd-wdog -d /opt/SUNWwbsvr/admin-server/config -r /opt/SUNWwbsvr -t /tmp/admin-server-9d93b4d6-1 -u root Listening at port: 8989 tcp 0 0 0.0.0.0:8989 0.0.0.0:* LISTEN #s1ws.sh admin-server start ***WARNING*** Web instance "admin-server" is still running. No need to start #s1ws.sh admin-server stop server has been shutdown ***WARNING*** Web instance "admin-server" is not running ***INFO**** Successfully stopped. #s1ws.sh admin-server status ***WARNING*** Web instance "admin-server" is not running #s1ws.sh admin-server start ***WARNING*** Web instance "admin-server" is not running Sun Java System Web Server 7.0U1 B06/12/2007 21:21 info: CORE3016: daemon is running as super-user info: CORE5076: Using [Java HotSpot(TM) Server VM, Version 1.5.0_09] from [Sun Microsystems Inc.] info: WEB0100: Loading web module in virtual server [admin-server] at [/admingui] info: WEB0100: Loading web module in virtual server [admin-server] at [/jmxconnector] info: HTTP3072: admin-ssl-port: https://chihungchan.blogspot.com:8989 ready to accept requests info: CORE3274: successful server startup ***INFO**** Successfully started. #s1ws.sh admin-server status Process ID: 7331 webservd-wdog -d /opt/SUNWwbsvr/admin-server/config -r /opt/SUNWwbsvr -t /tmp/admin-server-9d93b4d6-1 -u root Listening at port: 8989 tcp 0 0 0.0.0.0:8989 0.0.0.0:* LISTEN #s1ws.sh https-chihungchan.blogspot.com status Process ID: 5266 webservd-wdog -d /opt/SUNWwbsvr/https-chihungchan.blogspot.com/config -r /opt/SUNWwbsvr -t /tmp/https-chihungchan.blogspot.com-9d93b4d6-1 -u webservd Listening at port: 80 tcp 0 0 192.168.1.2:80 0.0.0.0:* LISTEN
After this 'shell script consolidation' exercise, we only need to remember and maintain one script instead of a half-a-dozen scripts or more.
Labels: shell script
posted by chihungchan at 9:19 PM
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