Networking, service management and ssh

22 March 2015

netstat

netstat  -alt   -a  list all
				-l  display listening socket
				-t  display tcp

watch

watch -d   highlight changes between updates

eg:
watch -d sudo iptables -nvL

Nagios monitoring

install LAMP stack with tasksel, tasksel is a package tools to install package on ubuntu

to see how may tasks can be installed, use

grep Task /usr/share/tasksel/ubuntu-tasks.desc, or use 
sudo tasksel

sudo tasksel install lamp-server

sudo apt-get install nagios3 -y

install mysql

sudo apt-get install mysql

mysql -u root -p

change root password

mysql_secure_installation

mysql -u root -p -e "SHOW DATABASES"

create Database

mysql -u root -p

mysql> SHOW DATABASES;   //list current database
mysql> CREATE DATABASE staff;  //create a new database
mysql> USE staff;

create table

mysql> SHOW TABLES;
mysql> CREATE TABLE department (did INT NOT NULL AUTO_INCREMENT, dname varchar(20), PRIMARY KEY(did));

mysql> DESCRIBE department;   //show table schema

rsyslog

latest version is 8.4

/etc/rsyslog.conf

local5.* /var/log/local5.log

by add this entry in rsyslog.conf, we can use logger to log the message to /var/log/local5.log

logger -p local5.info "script started"

logrotate

journalctl

part of systemd, responsible for viewing and log management

to view the journalctl, we must be the member of group adm, to add user to group adm, use usermod usermod -a -G adm username

using SSH

linux 4