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Archive for the ‘linux’ Category

Here are steps to configure DKIM on Postfix.

I configure DKIM on Postfix using the Ubuntu.

1. Install dkim

sudo apt-get update
sudo apt-get upgrade
sudo apt-get install opendkim opendkim-tools

2. Configure /etc/opendkim.conf

Domain              yourdomain.com
KeyFile             /etc/mail/mail.private
Selector            mail

3. Configure /etc/default/opendkim file

Add to the end of the file.

SOCKET="inet:8891@localhost"

4. Configure /etc/postfix/main.cf file

Add these configuration options to the end of the main.cf file.

# DKIM
milter_default_action = accept
milter_protocol = 2
smtpd_milters = inet:localhost:8891
non_smtpd_milters = inet:localhost:8891

5. Create directory /etc/mail and go there with cd

6. Generate keys in /etc/mail

sudo opendkim-genkey -t -s mail -d youdomain.com

After generating keys you’ll have mail.private and mail.txt in the directory. mail.private is your private key and mail.txt is the public key that you should set as TXT record of the domain.

7. Configure your domain TXT record for DKIM

mail.txt contains what you should set for the domain. It contains something like this:

mail._domainkey IN TXT "v=DKIM1; k=rsa; t=y; p=MIG...QAB" ; 
----- DKIM key mail for youdomain.com

This means that you need to create TXT record for you domain that has mail._domainkey as a “host name” and v=DKIM1; k=rsa; t=y; p=MI…AQAB as a “ip address/url”.

7. Start opendkim and restart Postfix

sudo service opendkim start
sudo service postfix restart

8. Useful links

help.ubuntu.com/community/Postfix/DKIM

Often, when I want to access my remote DigitalOcean server I have to find out the IP address of it. It isn’t comfortable for me so I decided to create a short alias for this IP in /etc/hosts. Now, after I’ve just made an alias, it’s really more comfortable and faster to login to the remove server via ssh.

/ets/hosts

127.0.0.1	localhost
127.0.1.1	infous-desktop
69.55.52.184	your_alias

Login via ssh using the alias

ssh user@your_alias

UPDATE:

The another way to set the ssh alias is to edit the ~/.ssh/config file.

Host your_alias
Hostname 192.0.2.1

Then to login just type:

ssh user@your_alias

But there’s a shorter way. Again, edit ~/.ssh/config and set:

Host your_alias
Hostname 66.66.66.66
User your_user

Now, you can login to your remote host via ssh like:

ssh your_alias

Thanks to everybody that commented this little note and suggested more elegant solutions!

I use Ubuntu 11.10 and in this short note I will provide steps to install PhpStorm.

1. Install Java

  sudo add-apt-repository ppa:webupd8team/java
  sudo apt-get update
  sudo apt-get install oracle-java7-installer

And check that Java’s been installed well:

  java -version

Or:

  javac -version

http://www.webupd8.org/2012/01/install-oracle-java-jdk-7-in-ubuntu-via.html

2. Download PhpStorm for Linux. You will download PhpStorm-5.0.4.tar.gz or something like this. BTW, I download it using Google Chrome.

http://wiki.jetbrains.net/intellij/Installing_and_running_PHPStorm_on_Ubuntu

3. Click on the downloaded archive so that Archive Manager will be opened. Extract all files to ~/PhpStorm/ if you don’t have this folder create it.

Don’t uncheck “Re-create folders” and “Overwrite existing files”. Everything should be like on the screenshots above. Otherwise the folder structure will be broken and you might get the error, when you’re launching phpstorm.sh:

Error: Could not find or load main class com.intellij.idea.Main

4. After the PhpStorm archive has been extracted quit the Archive Manager.

5. Open the Terminal and find phpstorm.sh inside ~/PhpStorm/PhpStorm-121.390/bin/ folder and run it:

  sudo ~/PhpStorm/PhpStorm-121.390/bin/phpstorm.sh

Congratulations, PhpStorm should be installed and launched!

Very often you need to send mail only. For example, your web site sends some notifications by email only. In this case, there’s a reason to configure you MTA (main transfer agent) only to send emails.

In case of Postfix, only some options should be edited to force your Postfix to send mail only.

/etc/postfix/main.cf

inet_interfaces = loopback-only
mydestination =

Comment existing inet_interfaces and mydestination if they’re exist by using # at the beginning of the line.

Don’t forget to reload Postfix:

  sudo /etc/init.d/postfix reload

For more information you may read Postfix on a null client.

Here’s a quick guide of installing Postfix (Mail Transfer Agent) on Ubuntu Linux.

To install Postfix type this command:

  sudo apt-get install postfix

/etc/postfix/main.cf is a main configuration file.

At least, configure a hostname in main.cf.

To find out the value of some configuration option type this command, for example, find out the myhostname value:

  postconf -d myhostname

After all the changes have been made to main.cf you should restart the Postfix to apply the changes:

  sudo /etc/init.d/postfix reload

Before all of the things you need Linux and something like Postfix installed. I test these examples on Ubuntu.

In the first example, we will create a file with the message and then we’ll send it to the recipient with help of sendmail command.

Create the file /tmp/mail.txt that contains the text and a new line at the end:

  sudo nano /tmp/mail.txt

Subject: the subject
This is the text of the message.
[new line]

Then type this:

  sendmail recipient@gmail.com < /tmp/mail.txt

I’ve tryed to use some GD functions in php. Locally everything is ok, I use xampp on Windows. But when I moved my site to the server I get this error:

PHP Fatal error: Uncaught exception ‘WideImage_Exception’ with message ‘WideImage requires the GD extension, but it’s apparently not loaded…

In my php app the WideImage library is used and it utilizes GD library. So, there isn’t GD extension installed. Well, let’s install it:

apt-get update
apt-get upgrade --show-upgraded
apt-get install php5-gd

After installing php5 gd library the error have been gone and WideImage classes begin to work properly.

PHP has lots of libraries and modules. To list them you can use this command:

apt-cache search php5-

Then you will see:

php5-cgi - server-side, HTML-embedded scripting language (CGI binary)
php5-cli - command-line interpreter for the php5 scripting language
php5-common - Common files for packages built from the php5 source
php5-curl - CURL module for php5
php5-dbg - Debug symbols for PHP5
php5-dev - Files for PHP5 module development
php5-gd - GD module for php5
php5-gmp - GMP module for php5
php5-ldap - LDAP module for php5
php5-mysql - MySQL module for php5
[...]

If you want to install a module run the command:

sudo apt-get install module-or-library-name

It’s possible to install several modules or libraries at once just separate them with a space.

I’ve just tried to understand what’s the problem with my crontab. I set it to a proper time but nothing happens. As i guessed the problem is in timezone.

I use Debian linux so here I’ll provide steps how I’ve fixed it:

Configure time zone with dpkg-reconfigure

    dpkg-reconfigure tzdata

Link localtime to a corresponding zoneinfo file

    ln -sf /usr/share/zoneinfo/Europe/Kiev /etc/localtime

In your case select your time zone.

Restart cron daemon

    /etc/init.d/cron restart

In my case this was the fix for the problem. I edited my contab and cron started to work like a Swiss watch