dscacheutil -flushcache

Now all is well in the world of DNS.

Last night I enabled PHP on the apache server built into Mac OSX on my new laptop and installed MySQL on it. I also set up some bash aliases to rsync commands so that I could synchronise the websites from the server to the laptop and back again.

Now that I had local copies of the sites that are synchronised it was time to turn my attention to synchronising the databases between the server and my local machine. I could of configured the server’s MySQL installation to allow remote connections, however, I did not want to do this for security reasons. I decided that I would connect to the MySQL server over SSH by forwarding a port on my local machine to a remote port on the server.

First I needed to create an SSH tunnel using the following command

ssh -fNg -L 3307:127.0.0.1:3306 server.host.name

The options for SSH are

• f
  • Requests SSH to background so that you do not have to keep a terminal connected to the server open
• N
  • Does not execute a remote command (useful for just forwarding ports)
• g
  • Allows remote hosts to connect to local forwarded ports
• L
  • Specifies that a local port (3307) is forwarded to the given host (server.host.name) and port (3306)

I created an alias to that command for easy use in future but I’ll need to make sure the tunnel is active before trying to connect to the remote server.

Next its time to turn our attention to actually connecting to the remote MySQL server.

mysql -h 127.0.0.1 -P 3307 -u username -p

The Options:

• h specifies the host to connect to (must be 127.0.0.1)
• P specifies the port to connect to (your locally forwarded port)
• u specifies the username to connect with
• p will prompt you for your password (–password=passtext can be used to give the password)

Thats if I wanted to connect to the remote MySQL server on the command line. The latest phpmyadmin has an option for syncronizing databases in which case you can put the above details and it will compare the databases and allow you to choose what to synchronise.

The appropriate setting can be found under:

System Preferences : Personal > Security > Firewall

I have mine configured to “Set access for specific services and applications” which normally asks me if I want to allow an application to accept incoming connections the first time I run it and that’s normally the end of it. The trouble comes when you try and update certain applications using Software Update. I’m not exactly sure what causes the problem but for some reason with specific applications the firewall then proceeds to ask you, each time, if you would like it to accept incoming network connections. This you can imagine is superlatively tedious.

The answer though is to just delete the application from you applications folder and reinstall it. The first time you open the freshly installed application it will ask the question and then bug you no more. Then all you have to worry about is not updating it via software update again.

telnet xxx.xxx.xxx.xxx 110 (xxx = mailserver)
+OK Hello there.
user USERNAME
+OK Password required.
pass PASSWORD
+OK logged in.
stat
+OK (Information about your mail)
quit
+OK Bye-bye.

To Test IMAP

telnet xxx.xxx.xxx.xxx 143
* OK (welcome message)
a login USERNAME PASSWORD
a OK login Ok.
a examine inbox
(Information about mail)
a logout
a OK LOGOUT completed

To Test POP3 over SSL

openssl s_client -connect xxx.xxx.xxx.xxx:995
Commands as above

To Test IMAP over SSL

openssl s_client -connect xxx.xxx.xxx.xxx:993
Commands as above

The way I did it was to have various directories in the /Users/username/Sites directory as is the normal set up but to have a symbolic link for each project that I wanted to have a better looking URL for so for example if my PHP My Admin was contained in the directory /Users/username/Sites/phpma then I would create a symbolic link to the directory /Library/WebServer/Documents/ using the command…

• ln -s /Users/username/Sites/phpma /Library/WebServer/Documents/phpma

Et Voila… I can now use and bookmark a shorter and less visually offensive URL to the sites I’m working on.

I’ve been meaning to try Joomla for some time and a friend mentioning it last night was the impetus for me to give it a go. I downloaded the latest stable version just now and decided to give it a go.

I was very impressed by the installation script and how it guides you through the installation process with handy guidance, however, I feel it falls down in one area.

On the penultimate installation screen there is an option to load default content into the database or previously saved data. This didn’t work for me and when I tried to go to the final screen of the installation I was greeted with the following errors…

Notice: Undefined index: DBtype in /var/www/xxx/htdocs/joomla_directory/installer/models/model.php on line 702

Fatal error: Call to undefined method JException::getNullDate() in/var/www/xxx/htdocs/joomla_directory/installer/helper.php on line 290

It took a bit of searching to figure it out but the problem lied with where joomla stores its configuration variables. At the second step of the installation there is a list of requirements one of which is write access to a file called ‘configuration.php’ in Joomla’s root directory. I noticed there’s a sample configuration file called ‘configuration.php-dist‘ so I copied it and gave the webserver write access to the file and the installer’s check seemed happy with this.

It turns out that the webserver either needs write access to the folder to write its own configuration file or if you provided the file with write access then it must be blank. I used touch to create the file and made it writeable by the webserver and the installation finally worked.

To set up a tunneled connection you issue the following command on any client:

ssh -fNg -L 3307:127.0.0.1:3306 myuser@remotehost.com

The first command tells ssh to log in to remotehost.com as myuser, go into the background (-f) and not execute any remote command (-N), and set up port-forwarding (-L localport:localhost:remoteport ). In this case, we forward port 3307 on localhost to port 3306 on remotehost.com.

Screenshot:

So if I ever get spam then I know exactly where it’s come from because each company / person has their own email address alias. It’s easy to stop them too, just delete the alias and no more spam! Not only that but the company or person who either spammed or allowed you to be spammed has just lost some credibility with you.

I got a Lloyds TSB phishing email this morning. I expect that you know what phishing emails are all about. I wasn’t fooled for an instant but I was interested in how they expected to trick people. The contents of the email were poorly coded HTML with images that were sourced from the lloydstsb.com site itself and an ugly link that blatantly was not kosher.

The email was sent to ‘undisclosed recipients’ a flaw in my plan you might think, not a problem, a quick look at the headers revealed that the email was sent to underu@mydomain.co.uk (I like to use aliases that are the company names themselves). This was the email alias I set up for www.underu.com the underwear site for men, when I shopped with them in the past.

I don’t know how my email address got from them to the attacker and I’m away from home at the moment. When I get back I’ll be in touch with UnderU and ask how my email address and who knows what other information could of been abused. I’ll update the post if / when they respond.

I was storing two timestamps (as a UNIX timestamp) in the database. One designating the date-time the user logged into the application and the other the date-time of the last activity the user performed. Because I was using UNIX timestamps, which are just the number of seconds sine the UNIX epoch, I subtracted one from the other and used that difference as the input to the PHP function date().

I couldn’t for the life of me work out why the date function was saying that I was logged in for an hour longer than I should have been and it was driving me crazy. It turns out that the reason was that my timezone locale setting in PHP is ‘Europe/London’ and that this causes the date function to adjust for British Summer Time (GMT + 1) thus when I used my timestamp difference in the date() function it translated the difference into a readable format but also added an extra hour.

The solution is to use gmdate() which is identical to the date() function except that the time returned is in Grenwich Mean Time format.