Posts Tagged ‘Debian’

Another option you can employ is xkill. This is preinstalled in Ubuntu, but you can install it via the Terminal (which you can open with CTRL + ALT + T) if necessary. When called, xkill will enable you to close any desktop app. Install it with the following command:

sudo apt-get install xorg-xkill

Once this is done, run xkill by simply typing

xkill

Your mouse pointer will then display a cross (or a skull), and all you need to do is left-click on the offending application.

If it’s not possible to close your unresponsive app with any of these desktop-focused methods, the solution might be the command line…

Send Email when IP Address Changes

Posted: 6 Μαρτίου 2018 in linux
Ετικέτες: , , , ,

1. Setup Gmail and mSMTP

This time we are using mSMTP because it’s easy, and Gmail because it’s free.

I would prefer to create a new Gmail account specific only for this purpose. Use your creativity to create long and obfuscated password, e.g. with mkpasswd -m sha-512 yOuRp4ssW0rD you can get a long string which is should be very nice for password.

Next, install mSMTP and its mail “client”:

https://wiki.debian.org/msmtp

sudoapt-get install msmtp mailutils

Then edit the config file at /etc/msmtp/ssmtp.conf:

 

root=youremail@gmail.com
mailhub=smtp.gmail.com:587
AuthUser=youremail@gmail.com
AuthPass=yOuRfUnKyP4ssWorD
UseTLS=YES
UseSTARTTLS=YES
AuthMethod=LOGIN

mSMTP is not a daemon, so don’t worry about starting the service or such.

Next, test your setup:

echo"test message"| mail -s "testing msmtp"yourothermail@gmail.com

Note the blank like after the subject, everything after this line is the body of the email. When you’re finished, press Ctrl-D. mSMTP may take a few seconds to send the message before closing.

apt-get install curl

2. The Script

#!/bin/bash
 
#Script to report public IP address change
#By: Soultidis D. Christos
 

curl ipinfo.io/ip > /home/username/emailscript/erxeteip.txt


oldip=`cat /home/username/emailscript/oldip.txt`
erxeteip=`cat /home/username/emailscript/erxeteip.txt`

if [[ $erxeteip = $oldip ]]
then

    #echo $oldip > /home/username/emailscript/oldip.txt
    echo "Kamia allagi"

else
    echo $erxeteip > /home/username/emailscript/newip.txt
echo $erxeteip > /home/username/emailscript/oldip.txt


    cat /home/username/emailscript/newip.txt | mailx -s "Dynamic Public IP Address" youremail@gmail.com

fi

This time we use Bash, because you might not realize that you’re already fluent with Bash.

Save this anywhere in your home folder. I personally have my own /home/username/emailscript/

 

3. Cron
To make this run periodically, add the script as a cron job. More detail on cron you can STFG (Search The Fine Google).

crontab -e

Then add this to run the script every 30 minutes

#*/30 * * * * /home/username/emailscript/ip.sh >/dev/null 2>&1

ΥΓ. θα πρέπει να δημιουργήσω το oldip.txt

 

Cron daemon is not running. I really screwed up with this some months ago.

Type:

pgrep cron 

If you see no number, then cron is not running. sudo /etc/init.d/cron start can be used to start cron.

EDIT: Rather than invoking init scripts through /etc/init.d, use the service utility, e.g.

sudo service cron start

How to install msmtp to Debian 10 for sending emails with gmail

 by caupo

I am making this post because last 2 days I tried to install msmtp to my Debian 10 server. Previously I used ssmtp where I did not have any problems but it cannot be installed at the time of making this tutorial. Because nobody is maintaining the package anymore or something like this as far as I understood.

I spend countless hours to the error that said my username and password is not accepted by Gmail. So here is my tutorial to how fully install it and configure it.

Step 1: Installing required packages.

sudo apt-get install msmtp msmtp-mta

Step 2: Create an app password in Google for msmtp

This (Step 2.* in this tutorial) was the missing piece of the puzzle which weren’t in any of the msmtp tutorials I did through. I found out about it in one of the Postfix tutorials where it was included after many hours of trial and error. Because at first, I thought the msmtp config file where was password field had to be filled with the same password with what you log in as a person to your account.

Go to: https://myaccount.google.com and log into the email account you want to start sending the emails.

Step 2.1: Select Security from the side menu and turn 2-Step Verification ON.

Step 2.2: After that click on App passwords

Step 2.3: Next up select Other (Custom name)

Step 2.4: Fill in the name as msmtp for example

Step 2.5: Get the password for your msmtp configuration file

Save this password to some notepad temporarily so you can copy & paste it later to a configuration file because once you click DONE you cannot see the password again. At least I have not found a way to re-open this popup.

Step 3: Create a configuration file

sudo nano /etc/msmtprc

Step 4: Configure msmtprc file

defaults
auth           on
tls            on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile        ~/.msmtp.log
account        gmail
host           smtp.gmail.com
port           587
from           username@gmail.com
user           username
password       password
account default : gmail

The username@gmail.com has to be changed in the config file with the email you used to create an app password

The user field where is username has to be changed as well. For example, if your email is john.doe@gmail.com then change username to john.doe.

defaults
auth           on
tls            on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
logfile        ~/.msmtp.log
account        gmail
host           smtp.gmail.com
port           587
from           john.doe@gmail.com
user           john.doe
password       fkelpwkdymcwslwo
account default : gmail

Step 5: Testing the email configuration

echo "Message" | mail -s "Title" youremailaddress@gmail.com

After that command, you should receive an email from your configured account.

Debian Linux Install OpenSSH SSHD Server

Posted: 24 Ιανουαρίου 2013 in linux
Ετικέτες: , , ,

by

How do I install OpenSSH sshd server under Debian GNU/Linux operating systems?

You need to use the apt-get or aptitude command to install OpenSSH server under Debian Linux. Open a terminal and type the following command to update package database as root user:
# apt-get update

Task: Install OpenSSH server Under Debian Linux

Type the following command:
# apt-get install openssh-server
Sample outputs:

Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  ssh-askpass rssh molly-guard ufw
The following NEW packages will be installed:
  openssh-server
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 318 kB of archives.
After this operation, 717 kB of additional disk space will be used.
Get:1 http://mirror.anl.gov/debian/ squeeze/main openssh-server amd64 1:5.5p1-6+squeeze1 [318 kB]
Fetched 318 kB in 3s (89.0 kB/s)
Preconfiguring packages ...
Selecting previously deselected package openssh-server.
(Reading database ... 153448 files and directories currently installed.)
Unpacking openssh-server (from .../openssh-server_1%3a5.5p1-6+squeeze1_amd64.deb) ...
Processing triggers for man-db ...
Setting up openssh-server (1:5.5p1-6+squeeze1) ...
Creating SSH2 RSA key; this may take some time ...
Creating SSH2 DSA key; this may take some time ...
Restarting OpenBSD Secure Shell server: sshd.

By default openssh will run on the TCP port 22. You can verify the same with the following command:
# netstat -tulpn | grep :22
Sample outputs:

tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      3946/sshd
tcp6       0      0 :::22                   :::*                    LISTEN      3946/sshd

You can connect to the Openssh server, type:
$ ssh user@localhost
$ ssh user@sever-ip-here

How Do I Start / Stop / Restart OpenSSH Server Under Debian Linux?

Type the following commands as root user:
# service ssh stop
# service ssh start
# service ssh restart
# service ssh status

OR
# /etc/init.d/ssh stop
# /etc/init.d/ssh start
# /etc/init.d/ssh restart
# /etc/init.d/ssh status

Sample session:

Fig.01: OpenSSH under Debian LinuxClick to enlarge the image

How Do I Open Port 22 At The Firewall Level?

Edit your firewall script and append the following rule to restrict access to 192.168.1.0/24:

/sbin/iptables -A INPUT -s 192.168.1.0/24 -m state --state NEW -p tcp --dport 22 -j ACCEPT

Save and close the file. OR, you can type the command as follows and save it to your firewall config file:

# /sbin/iptables -A INPUT -s 192.168.1.0/24 -m state --state NEW -p tcp --dport 22 -j ACCEPT
# iptables-save > /path/to/your.firewall.conf

How Do I Configure and Secure OpenSSH Server under Debian Linux?

You need to edit the /etc/ssh/sshd_config file using the text editor such as vi, run:
# vi /etc/ssh/sshd_config
See this article which explains config option to tweak in order to improve OpenSSH server security.

Πηγή : http://www.cyberciti.biz/faq/debian-linux-install-openssh-sshd-server/