How do I find out my public IP address on the Linux and OS X Unix command line to use with my own bash shell script without using third party web site? Is there command-line option which will show my dynamic IP address on a Ubuntu or Fedora Linux?
There are many ways to find out your public IP address or wan (Wide Area Network) IP on a Linux or Unix-like operating systems such as FreeBSD, OpenBSD, NetBSD, Apple OS X, and others.
Explain IP addresses
An IP is short for Internet Protocol. It is used to identify computers or mobile devices on the Internet. Each device connected to the Internet has an IP address. IP address can be used to personalize information.
I‘m a new Linux / Unix system user. How can I set encrypted tunnel between my desktop/laptop computer and server in a remote data center to bypass the limits in a network? How do I create a reverse SSH tunnel on Unix-like systems?
SSH tunnelling can be thought as a poor-man’s-VPN. It is handy in situations where you would like to hide your traffic from any body who might be listening on the wire or eavsdropping.
You can use such tunnel between your computer and your Unix/BSD/Linux server to bypass limits placed by a network or to bypass NAT, and more. Lire la suite…
on injecte la base: [maitre]# mysql -u root -pMDP votre_bdd.sql > votre_bdd.sql
Maintenant, on va activer la réplication de la base MySql du serveur maître sur l’esclave: sur le serveur maître: tout d’abord on va se connecter sur la base
[maitre]# mysql -u root -pMDP
Puis on bloque la base en lecture seule mysql>: FLUSH TABLES WITH READ LOCK;
On repère la position de la base:
mysql > SHOW MASTER STATUS;
------------------ ---------- -------------- --------------------------
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB |
------------------ ---------- -------------- --------------------------
| mysql-bin.000003 | 73 | test,bar | foo,manual,mysql |
------------------ ---------- -------------- --------------------------
1 row in set (0.06 sec)
et on note: mysql-bin.000003 ← le log bin à utiliser 73 ← la position du log évidemment à adapter suivant le cas.
sur le serveur esclave: on se connecte aussi à la base mysql [esclave]# mysql -u root -pMDP
on stoppe la réplication en cours mysql>stop slave;
on fait une RAZ de la réplication mysql>reset slave;
On va positionner le serveur esclave comme le maître: mysql> CHANGE MASTER TO MASTER_HOST = 'IP', MASTER_USER = 'repli', MASTER_PASSWORD = 'repli', MASTER_LOG_FILE = 'mysql-bin.000003', MASTER_LOG_POS = 73;
on démarre la réplication mysql> start slave;
on vérifie qu’on n’a pas d’erreur
mysql> show slave statusG*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.94.8.58
Master_User: repli
Master_Port: 3306
Connect_Retry: 60
Master_Log_File: mysql-bin.000003
Read_Master_Log_Pos: 73
Relay_Log_File: GLPI_esclave-relay-bin.000024
Relay_Log_Pos: 660186
Relay_Master_Log_File: mysql-bin.000003
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
******
Last_Errno: 0
Last_Error:
******
Seconds_Behind_Master: 0
1 row in set (0.00 sec)
on se déconnecte de mysql mysql>exit;
sur le serveur maitre on déverrouille l’écriture sur la base mysql> UNLOCK TABLES;
on se déconnecte de mysql mysql>exit;
et pour finir on lance le script de lancement automatique des services heartbeat/mon/http/myslq:
[maitre]#./startHA
sur le serveur maitre c’est le même script sauf le service Mon en moins: [esclave]#./startHA
on vérifie que l’IP virtuel est actif sur le serveur maitre:
[maitre]#ifconfig
eth0:0 Link encap:Ethernet HWaddr 00:22:19:D7:73:48
inet adr:10.94.8.56 Bcast:10.94.15.255 Masque:255.255.248.0
UP BROADCAST RUNNING MULTICAST MTU:1492 Metric:1
Interruption:16
et dans le navigateur firefox, on fait un test de connection:
http://appliweb.com
SI TABLE CRASHED :
d’après le log, on repère la table dite crashed
connexion à mysql : #mysql -u root -pMDP ;
on sélectionne la base mysql>use votre_bdd ;
on répare la table mysql>repair table nomdelatable ;
How do I find out running processes were associated with each open port? How do I find out what process has open tcp port 111 or udp port 7000 under Linux?
You can the following programs to find out about port numbers and its associated process:
netstat – a command-line tool that displays network connections, routing tables, and a number of network interface statistics.
fuser – a command line tool to identify processes using files or sockets.
lsof – a command line tool to list open files under Linux / UNIX to report a list of all open files and the processes that opened them.
/proc/$pid/ file system – Under Linux /proc includes a directory for each running process (including kernel processes) at /proc/PID, containing information about that process, notably including the processes name that opened port.
You must run above command(s) as the root user. Lire la suite…
I‘m a new Unix system user. How do I use sudo command without a password on a Linux or Unix-like systems?
Some times you may need to run a command with root privileges, but you do not want to type a password using sudo command. This is useful for scripting or any other purpose. This can be achieved by editing /etc/sudoers file and setting up correct entries.
You need to consider any security consequence of allowing a sudo command execute without a password. Lire la suite…
