Wednesday, February 8, 2017

Linux PORTs and PIDs

Get PID of a process running on a given PORT



down voteaccepted

$ sudo netstat -nlp | grep :80
tcp  0  0  0.0.0.0:80  0.0.0.0:*  LISTEN  125004/nginx
You can also use lsof:
$ sudo lsof -n -i

Nginx and AWS


To Install Nginx from Source

cd /tmp #so we can clean-up easily
wget http://nginx.org/download/nginx-1.10.0.tar.gz
tar zxvf nginx-1.10.0.tar.gz && rm -f nginx-1.10.0.tar.gz
cd nginx-1.10.0
sudo yum install pcre-devel openssl-devel #required libs, not installed by default
./configure \
  --prefix=/etc/nginx \
  --conf-path=/etc/nginx/nginx.conf \
  --pid-path=/var/run/nginx.pid \
  --lock-path=/var/run/nginx.lock \
  --with-http_ssl_module \
  --with-http_v2_module \
  --user=nginx \
  --group=nginx
make
sudo make install
sudo groupadd nginx
sudo useradd -M -G nginx nginx
rm -rf nginx-1.10.0

You'll then want a service file, so that you can start/stop nginx, and load it on boot.
Here's one that matches the above config. Put it in /etc/rc.d/init.d/nginx:
#!/bin/sh
#
# nginx - this script starts and stops the nginx daemon
#
# chkconfig:   - 85 15
# description:  NGINX is an HTTP(S) server, HTTP(S) reverse \
#               proxy and IMAP/POP3 proxy server
# processname: nginx
# config:      /etc/nginx/nginx.conf
# config:      /etc/sysconfig/nginx
# pidfile:     /var/run/nginx.pid

# Source function library.
. /etc/rc.d/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

# Check that networking is up.
[ "$NETWORKING" = "no" ] && exit 0

nginx="/etc/nginx/sbin/nginx"
prog=$(basename $nginx)

NGINX_CONF_FILE="/etc/nginx/nginx.conf"

[ -f /etc/sysconfig/nginx ] && . /etc/sysconfig/nginx

lockfile=/var/run/nginx.lock

make_dirs() {
   # make required directories
   user=`$nginx -V 2>&1 | grep "configure arguments:" | sed 's/[^*]*--user=\([^ ]*\).*/\1/g' -`
   if [ -z "`grep $user /etc/passwd`" ]; then
       useradd -M -s /bin/nologin $user
   fi
   options=`$nginx -V 2>&1 | grep 'configure arguments:'`
   for opt in $options; do
       if [ `echo $opt | grep '.*-temp-path'` ]; then
           value=`echo $opt | cut -d "=" -f 2`
           if [ ! -d "$value" ]; then
               # echo "creating" $value
               mkdir -p $value && chown -R $user $value
           fi
       fi
   done
}

start() {
    [ -x $nginx ] || exit 5
    [ -f $NGINX_CONF_FILE ] || exit 6
    make_dirs
    echo -n $"Starting $prog: "
    daemon $nginx -c $NGINX_CONF_FILE
    retval=$?
    echo
    [ $retval -eq 0 ] && touch $lockfile
    return $retval
}

stop() {
    echo -n $"Stopping $prog: "
    killproc $prog -QUIT
    retval=$?
    echo
    [ $retval -eq 0 ] && rm -f $lockfile
    return $retval
}

restart() {
    configtest || return $?
    stop
    sleep 1
    start
}

reload() {
    configtest || return $?
    echo -n $"Reloading $prog: "
    killproc $nginx -HUP
    RETVAL=$?
    echo
}

force_reload() {
    restart
}

configtest() {
  $nginx -t -c $NGINX_CONF_FILE
}

rh_status() {
    status $prog
}

rh_status_q() {
    rh_status >/dev/null 2>&1
}

case "$1" in
    start)
        rh_status_q && exit 0
        $1
        ;;
    stop)
        rh_status_q || exit 0
        $1
        ;;
    restart|configtest)
        $1
        ;;
    reload)
        rh_status_q || exit 7
        $1
        ;;
    force-reload)
        force_reload
        ;;
    status)
        rh_status
        ;;
    condrestart|try-restart)
        rh_status_q || exit 0
            ;;
    *)
        echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload|configtest}"
        exit 2
esac
Set the service file to be executable:
sudo chmod 755 /etc/rc.d/init.d/nginx
Now you can start it with:
sudo service nginx start
To load it automatically on boot:
sudo chkconfig nginx on
Finally, don't forget to edit /etc/nginx/nginx.conf to match your requirements and run 
sudo service nginx reload 
to refresh the changes.

To disable Nginx 


sudo /etc/init.d/nginx stop
Or 

sudo service nginx stop

sudo chkconfig nginx off
then confirm with
chkconfig --list | grep nginx

To list all the autostart services or processes 

sudo chkconfig 

To Reload Nginx


sudo nginx -s reload

or

 sudo service nginx reload

Reload is required whenever nginx.conf file changes