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Wed 10 Mar 2010

Introducing DNS Agent

For a long time, I've been wanting to replace DNSUpdate with my own app (DNSUpdate had been keeping my server's IP address record on dyndns.com updated in sync with my domain name whenever that IP address changes).

Ever since the Work Around Bonjour troubles we've had on OS X 10.4.7, DNSUpdate hadn't been working quite right, always stalling when you try to install its IP-monitoring daemon, and even now on Snow Leopard.

So building something to replace it had been on my radar for some time. And the time came when I received a request to add dynamic DNS client support to DNS Enabler Snow. I worked on this over the last couple of months and I have now a new version of DNS Enabler Snow to release, which I'll do next, but first I'll introduce its companion app, DNS Agent :

DNS Agent can update a DNS Enabler Snow-enabled DNS Server with a client's ever-changing IP address (i.e., those machines on dynamically assigned IP addresses or those machines always on the move), as shown above.

Or, DNS Agent can update dyndns.com, if the user has a member's account with dyndns.com (see below).

Setting it up to use with dyndns.com is dead easy - just enter your members.dyndns.com userID and password by clicking on "Set Up Update Keys" button, enter the host name(s) of the machine for which you want DNS Agent to update dyndns.com, start the IP-address monitoring daemon, and you're good to go (as shown above). You can then close the app because the daemon continues to run, even across reboots, until you stop it.

Setting DNS Agent to work with a DNS Enabler Snow DNS Server is just as easy. I'll come to it next when I've finished updating DNS Enabler Snow's web page.

But DNS Agent is available now. Only for Snow Leopard.

Posted at 10:34AM SGT | permalink

Sat 06 Mar 2010

MailServe Snow 4.1.4

Category : Technology

I've updated MailServe Snow to 4.1.4, so that it can also handle 2048 bit length SSL keys.

On top of that, I've also added a new custom Procmail settings button to the Spam panel.

MailServe Snow uses Procmail to integrate Postfix, Dovecot and SpamBayes to implement spam filtering. With version 4.1.4, the user can now set up custom Procmail directives to be processed before or after the default procmail directives for handling spam filering.

The default procmailrc can also be edited and there's a button to revert the directives back to their default state if, for some reason, the user's custom edits fail to work.

Download the latest MailServe 4.1.4 now.

I have a new version of DNS Enabler Snow to be released next. Plus a new companion app, DNS Agent. They will work in concert to allow client machines on dynamic IP addresses to update the DNS server whenever their IP addresses change. With this, users can now set up their own dynamic DNS service, much like dyndns.com.

Actually, I've made DNS Agent able to also update dyndns.com so that I can now use my own app instead of DNSUpdate. It seems to be working well on my live site but I'll need to test it for a few days more.

Plus, I'm also working (with my friend, Hai Hwee) on the iPhone and the iPad simulator to port Maven (which will soon be renamed) and Luca to these platforms. So lots of work. More work, less talk, more reading, and more time with the family - that comes pretty close to paradise on earth, at least for me.

Posted at 12:31PM SGT | permalink

WebMon Snow 4.0.5 Released

Category : Technology

I've updated WebMon Snow to 4.0.5.

From this version, on WebMon Snow will create SSL test certs and cert requests at a default 2048 bits instead of the previous 1024 bit standard.

There is a movement towards supporting only 2048 bit length keys by Certificate Issuers and browser makers by December 31st 2010 and this is to prepare for it.

According to the GoDaddy link that I quoted, above, "It is estimated that the computer power required to break 1024-bit length secure certificate private keys will exist by 2011."

But it seems like it's already been broken yesterday. (See "RSA 1024-bit private key encryption cracked").

So, right on time. And I'll be updating MailServe Snow, too.

Posted at 9:49AM SGT | permalink

Fri 29 Jan 2010

MailServe Snow 4.1.3 Released

Category : Technology

I've released MailServe Snow 4.1.3.

It includes a few new features. I've added the ability to create and delete mail users from within MailServe, and decide if the user should be hidden from the Login Window and whether he has the full complement of the standard OS X home folder or a minimal home folder to store only the IMAP folders.

The administrator can also decide for this user if his spam mail will be deleted right away or continue to collected in the spam folder.

Dovecot has been updated to the latest version 1.2.10.

Fetchmail was updated by Apple to 6.3.11 via the latest software updates, and this version has a much less chatty log and so the Fetchmail log has been merged with the Postfix and Dovecot log in the MailServe Log Panel.

Finally, there used to be a 16K limit to the size of the Aliases field (and all other similar fields). This limit has been removed and they can now contain as much information as the mail admin wants.

This is a release that includes a substantial amount of code changes, plus a lot of tweaks that the user don't see underneath - unless I left some bugs and, of course, hell may then break loose. But I've tested as much as I can and I've been using it on my live server for a week now. Hope that I've done enough.

This is really the time to put in the new features - when Snow Leopard has already settled in for a while. It would have been unwise to attempt all these when Snow Leopard just came out. So it's a bit of an inversion (in terms of business practice) from what the users would have expected. But this is dictated by the realities of living at the cutting edge of technology. I think this works. (And I'm now going to work on a major new feature addition to DNS Enabler Snow, though there's a new toy - the iPad simulator - that's calling out its siren song.)

Posted at 11:38AM SGT | permalink

Wed 27 Jan 2010

Dovecot 1.2.10

Category : Technology

Dovecot 1.2.10 is out, so I've updated the latest test version of MailServe Snow 4.1.3 to include it.

I might also be able to include a feature that'll allow the user to set up his own custom procmail recipes, in addition to the one that's set up for the SpamBayes junk-mail filtering to work.

This is going to be a pretty significant update.

Posted at 4:42PM SGT | permalink

Mon 25 Jan 2010

Dovecot 1.2.9

Category : Technology

I forgot to mention that the latest (testing-stage) MailServe Snow 4.1.3 also includes the latest Dovecot 1.2.9 release.

But you'll need to save your MailServe config and then do a de-install of MailServe so that MailServe can then replace it with the new version of Dovecot when you start up all the services again.

I'm starting on a new version of DNS Enabler for Snow Leopard that will hopefully make it able to support dynamic DNS updates from client machines that are on dynamic IP addresses.

Posted at 8:50AM SGT | permalink

Sat 23 Jan 2010

MailServe Snow 4.1.3

Category : Technology

There is now a new 4.1.3 version of MailServe Snow (as yet unreleased). I've added the ability to create new OS X users from within MailServe.

The administrator has the option to create standard OS X users (with the full complement of folders inside their home folder) or ones with only a minimal home folder (to contain only the IMAP folders) and these latter type of users are hidden in the OS X login window.

It needs more testing before I'll release it. I'm using it now on my live server.

There's one more new feature - the ability to indicate that spam for a specific user should be sent straight to the black hole, via /dev/null, with just one click. I've used this to make sure that my son Brendan never ever gets to see the spam/junk/filth that was heading his way (or at least the ones that were filtered off by SpamBayes - a few still get through unfortunately).

Because the users thus created who have a minimal home folder do not appear in the login users list, they will also not show up in Systems Preferences' Accounts pane. So, how do we delete them when necessary? I've given the mail administrator the ability to delete users but, to be safe, MailServe will not delete admin-level users.

Current MailServe Snow users who would like to try it can just contact me and I'll send the copy over.

Posted at 6:52PM SGT | permalink

Mon 18 Jan 2010

Designing Software Cinematically

Category : Commentary

Actually there's one book I'd like to recommend that software developers read (okay, only if you also love movies) and that's Robert McKee's "Story: Substance, Structure, Style and The Principles of Screenwriting".

Long ago in the '80s, Brenda Laurel made the analogy that designing computer systems is a lot like figuring out the manifold activities that go towards putting together a play. That was in her book, "Computers as Theatre" which, though rather dated by now, is still a classic. And one can argue that with the Internet, YouTube and all, its time has come.

So, if you're of such a persuasion, you can find much of relevance in Robert McKee's exhortation to tell good stories always. For in telling good stories, you pare away at the details, so that what you have left is all that you need to keep the viewer on the message.

Where computer-systems design and story-telling diverges is when after you've set up a sense of expectation (via the layout of the "scene"), in computer-systems you must go on to fulfill the expectations, but in a play, the playwright often does just the opposite, building suspense and creating the drama that keeps the audience transfixed.

But the point is, the principal creative activity in both endeavours is the setting up of the scene (because in computer-systems, if you create in the user the right expectations, he will already know what to do, and you save yourself the bother of having to write a thick user guide). And the principles are quite similar in both cases, which shouldn't be surprising if you're a software designer who also loves watching movies.

Just one more thing. Reading the book, you'll enjoy movies a lot more because Robert McKee deconstructs famous scenes from e.g., Casablanca and also one from Chinatown, which struck me because, watch this. In the scene the detective slaps the woman, saying, "You're lying. Tell me who she is!". "She's my daughter." Slap. "She's my sister." Slap. "She's my daughter." Slap. "She's my daughter. And my sister!" Slaps. Then the horror, as the truth dawns on the detective (and also on us, the audience).

Now watch how Steve Jobs uses this technique, in the launch of the iPhone. "We're launching three products today. An iPod. A phone. And an Internet communicator. An iPod, a phone. Are you getting it?" And the crowd goes wild.

Posted at 9:50AM SGT | permalink