How to ssh without password

Sometimes we need to remotely copy and backup files to a backup server every night. In linux, it is very easy to do so.

Here's how...

At local host, generate ssh key.

1. guest@guest:~$ ssh-keygen -t rsa
2. Generating public/private rsa key pair.
3. Enter file in which to save the key (/home/guest/.ssh/id_rsa):
4. Enter passphrase (empty for no passphrase):

5. Enter same passphrase again:
Your identification has been saved in /home/guest/.ssh/id_rsa.
Your public key has been saved in /home/guest/.ssh/id_rsa.pub.
The key fingerprint is:
0c:51:be:1e:2d:1c:8f:34:18:b9:8e:21:a3:50:6e:95 guest@guest

After that, at the remote linux host, copy the file in /home/guest/.ssh/id_rsa.pub

Create directory .ssh

1. myhost@myhost:~$ mkdir .ssh
2. From guest, guest@guest:~$ scp ~/.ssh/id_rsa.pub myhost@myhost:~/.ssh/authorized_keys
3. Change to file permission, myhost@myhost:~$ chmod 600 .ssh/authorized_keys
4. Then now you can ssh into the myhost without any password.
5. guest@guest:~$ ssh myhost@remoteIPaddress
6. guest@myhost:~$ 


Then, you are ready to go...

PostgreSQL Need To Know

Installation

# apt-get install postgresql-8.3 postgresql-contrib-8.3

Note:

postgresql-contrib-8.3 contains additional facilities for postgresql

Configuration file location

# /etc/postgresql/8.3/main/postgresql.conf

# /etc/postgresql/8.3/main/pg_hba.conf

Actual location is /var/lib/postgresql/8.3/main/postgresql.conf

To configure connection for postgresql, edit pg_hba.conf

# "local" is for Unix domain socket connections only
local     all     all     ident sameuser (default) -> meaning database user does not need password for database editin.

It should be changed from ident sameuser to md5, this will require password login for database user for security purposes.

Things I Learn Today

I have learned something today that I would like to share here.

Something useful in postfix,

# postqueue -p (list active queue)

# postsuper -d msgID (delete queue id)

# postsuper -d ALL (delete all queue)

Feelings For Mother

My mom passed away a month ago. I was very sad as she has worked so hard to raise me and my sister and she has never rested enough until the day she passed away. I felt really guilty of not spending more time with her when she is still around.

My mom always encourages us to eat fruits and vegetables to stay healthy. She is a hardworking and a loving mother. She always worked non-stop not only at work but at home as well. I really felt ashame of myself of not helping my mom to do the household chores and be there when she needs me.

Today, I was cleaning my mom's room. I found some old photos of me, my sister and my mom together. When I saw those photos, those days were happy moments. I felt so sorry because I did not share my feelings with her and make her happy.

I have promised to my mom that I will take care of my sister and I will keep that promise.

Mommy, I Love You! You are the greatest mother in the world!

How to setup a Linux Debian Etch/Lenny Samba Server

Today, I would like to share my experience on how to setup a Linux Debian Etch Samba Server. I believe it works for Debian Lenny as well because I have upgraded my Linux Debian Etch Samba Server to Lenny successfully without any issues.

Here are the steps.

1. Setup a normal Debian Etch or Lenny server.

2. Install basic packages by using apt-get install such as ssh, sudo, apache2, php5, phpsysinfo and etc

3. Install Samba packages - samba, samba-common, samba-doc, smbfs, smbclient and swat

4. After install the packages, it's time to configure Samba for your clients.

First, add your clients by using adduser command.

# adduser john

Then disable remote login such as ssh, by editing file /etc/passwd

# vi /etc/passwd

Change /bin/sh to /bin/false for user john

# john:x:1002:1002:,,,:/home/john:/bin/false

Save the file.

Secondly, add related group to enable users in the group to share files.

Add group command

# addgroup itgroup

Add related users into the group

# vi /etc/group

# itgroup:x:1003:john (user john is added into itgroup to share files)

Save the file.

Now it's the time to configure Samba. Remember that we have installed swat during the step 3 above. It is Samba Web administration tool. To access this web page, go to http://ipaddress:901

It will prompt out username and password to login. To login, please use root and root password. You can configure anything inside the web.

Here's my working Samba configuration in /etc/samba/smb.conf

# Samba config file created using SWAT
# from 192.168.xxx.xx (192.168.xxx.xx)
# Date: 2008/12/17 12:35:30

[global]
  workgroup = IT
  netbios name = SAMBA
  server string = %h server
  encrypt passwords = false
  passwd program = /usr/bin/passwd %u
  passwd chat = *Enter\snew\sUNIX\spassword:* %n\n *Retype\snew\sUNIX\spassword:* %n\n *password\supdated\ssuccessfully* .
  syslog = 0
  log file = /var/log/samba/log.%m
  max log size = 1000
  os level = 64
  local master = No
  domain master = No
  dns proxy = No
  wins support = Yes
  panic action = /usr/share/samba/panic-action %d
  invalid users = root
  read list = john
  write list = jay (edit write list follow your own needs, write list users are users that own the folders)

hosts allow = 192.168.1.0/24, 192.168.2.0/24

[homes]
  comment = Home Directories
  valid users = %S
  create mask = 0700
  directory mask = 0700
  browseable = No

[printers]
  comment = All Printers
  path = /var/spool/samba
  create mask = 0700
  printable = Yes
  browseable = No

[print$]
  comment = Printer Drivers
  path = /var/lib/samba/printers
  read only = No
  browseable = No

[winreg]
  comment = registry for windows
  path = /usr/share/doc/samba-doc/registry
  guest ok = Yes

[data]
  comment = Data Directories
  path = /data
  admin users = jay
  force user = jay 
  force group =  itgroup
  read only = No
  create mask = 0640
  directory mask = 0740 (only folder owners can edit the file)
  inherit permissions = Yes (This setting will preserve the  group permissions and ownership although the file owners have edited the files) 
  inherit acls = Yes

You can manually edit the samba configuration or edit the file by using swat. Both is the same. Remember to restart samba service whenever you change any settings in the samba configuration file.

Restart samba command -> # /etc/init.d/samba restart

After that, set samba password for your user login by using smbpasswd command.

# smbpasswd -c /etc/samba/smbpasswd (create a file to store samba password)

# smbpasswd -a john (add user john into the samba password file) 

# smbpasswd -x john (delete user john from the samba password file)

After you have added related users, it is time for your clients to connect the samba server. Before that, your Windows client need to install the windows registry file in the samba server to enable blank username and password for Windows access. It has been configured in my configuration file above. The windows registry path is located at /usr/share/doc/samba-doc/registry

To access your samba server from Windows PC, type IP address and then access the folders. It will prompt out login name and password. If you are able to login with the correct password that created earlier, then your linux Samba server is ready for implementation. It's that simple. 

More tips and tutorials coming soon. Enjoy!!!

TM SME Biz Net 2009

This morning I went to SME Biz Net 2009 at Star City Hotel organized by TM. There are three agendas during the session.
1.Talks about SMIDEC Grant
-> SMIDEC stands for Small and Medium Industries Development Corporation. It helps to promote and coordinate the development of SMEs in Malaysia.
-> For more information, please log on to http://www.smidec.gov.my
-> It is very helpful to new business starters. Take a look if you are interested to start a business.

2. SME Biz Net Package
-> The package basically includes Internet Broadband Services for business and also some other promotions. They also promote Toll Free number for SMEs.

-> I received a new information from TM presenter that they provide one stop solution from their new website that is http://www.tmsme.biz

The site is developed to provide information for SMEs in developing a successful business. It has latest news and events to be launched in the coming months.

3. E-Secure Solution by ESS

-> Basically, it is a simple and brief description of the importance of Internet security. TM also provides E-Secure in their Internet services for SMEs.

Overall, many business partners attended the event and I'm satisfied with the information provided.

Welcome to Linux Tips and Tricks

I'm a fan of Linux and lets share our experience with open source applications.

Here's some basic Linux tips for starters

1. Prevent root logins

# Edit ssh configuration file (Debian and Fedora)

-> vi /etc/ssh/sshd_config

-> PermitRootLogin no (default is yes)

2. Display Linux tasks

# Use top command

3.  To see every process on the system using BSD syntax

# Use ps ax command

To find specific process running, use the command below:

-> ps ax | grep apache2 (This will check the apache2 running process)

4. To kill a Linux process

-> kill -9 123 (123 refers to pid in Linux process, you can view the pid by using ps ax command above)

My First Ever Blog

Hi all,

This is the first time I've decided to create a blog to share my learnings and personal feelings with all the people around the world.

Any posts would be most welcome and lets us share together.