August 20, 2010

Dovecot 2.0 install

Ran into some minor hurdles in upgrading to Dovecot 2.0. Definitely need to read the docs on upgrading a bit better next time... But after some work, I have it running here.

Found an undocumented configuration option called service(dns_client), this was logged when it was trying to use the user 'dovecot' instead of the OS X user '_dovecot', which I had already listed in my config for some other services. Simple fix here, I took out the lines specifying 'user = _dovecot' for my listed services, and instead used this line at the top of my config file:

default_internal_user = _dovecot

Second issue that I ran into was the default install looks for a user called dovenull. This user didn't yet exist on my system, so I needed to create it (as opposed to defining a different existing user for this function, which I didn't want to do). My concern is that when Dovecot 2 is rolled into OS X, a new dovenull user will be created, or more likely, _dovenull. So, I can create the user now, and have it later overwritten, and who knows what issues might arise, or I create this user with a different name to avoid the whole issue.

Creating unix level users with OS X is a bit more involved than other systems, but once you read up on the dscl command, you can find some quick examples of this. The trickiest part is picking an appropriate UniqueID for the user.

Here's a handy command for listing all of the used UniqueIDs:
sudo dscl . -list /Users UniqueID | awk '{print $2}' | sort

We'll use a similar command to get a list of all Group IDs that are used:
dscl . -readall /Groups | grep PrimaryGroupID | awk '{print $2}' | sort

It seems best to avoid the range 0-99, and the low 200's are slowly filling up for UserIDs. There's nothing from 100-199, and OS X starts creating new users (the ones used by the Finder) at 501. Why 100-199 was left blank, I don't know, and who knows what other 200 range codes might be used in a future OS update. For the Group IDs, 0-100 were full up, again the break from 101-199, starting again with the low 200's, then starting with the 400's. So, throwing caution to the wind, I'll use 301 for my new user and the group associated with it, created with the following commands:

sudo dscl . -create /Users/_dovenull
sudo dscl . -create /Users/_dovenull UniqueID 301
sudo dscl . -create /Users/_dovenull PrimaryGroupID 301
sudo dscl . -create /Users/_dovenull UserShell /usr/bin/false
sudo dscl . -create /Users/_dovenull RealName "Dovenull"
sudo dscl . -create /Users/_dovenull NFSHomeDirectory /var/empty
sudo dscl . -append /Users/_dovenull RecordName _dovenull

sudo dscl . -create /Groups/_dovenull
sudo dscl . -create /Groups/_dovenull PrimaryGroupID 301
sudo dscl . -append /Groups/_dovenull RecordName dovenull

I set the UserShell above so that the user has no shell access, and set NFSHomeDirectory so that there is no home directory.

Once I had the _dovenull user created, I was successfully able to get dovecot running, so far, no issues.

Posted by Jim at 10:00 PM | TrackBack

August 9, 2010

Otterbox Defender case for iPhone 4

It is worth stressing that anyone with an iPhone should have a case of some sort, the day this case arrived in the mail here, that very morning I dropped my iPhone 4 for the first time, and all I could do was watch in horror as it fell to the floor, my muscles frozen, unable even to move my foot to brace the phone's fall. Think of all the times your phone is out, you tapping the screen, holding it up for friends, taking pictures. Sooner or later, it's going to drop.

That said, I'm extremely happy to have my new iPhone 4 wrapped in the Otterbox Defender case, and as usual they've done an outstanding job with this version.

The shape of the new iPhone 4 has let them come up with what I think is a much more user friendly case. The feel of this case is much nicer than that Defender cases for prior generations of iPhone, which were themselves darned good. The silicone exterior is textured, providing for an excellent grip, without being too tacky to the touch. It slides in and out of my pocket far better than prior models, which I generally would never use without the included holster. Having used my iPhone 4 without a case for a few weeks, I had become accustomed to sliding it into my pocket, and discovered that this new case supported that habit quite well. The downside though is that the case isn't quite as grippy on flat surfaces, quite often I would have my phone charging in my car, and have the case resting on the armrest between the front seats. Prior cases would stay put around corners and hard braking, this new case has a harder time staying put, but overall this is, to me, an acceptable trade off.

The included holster has also been redesigned, the original iPhone version had the phone sliding straight down into the holster, the 3G version had the bottom of the phone sliding in at a slight angle, then the rest of the phone clicking into place. The iPhone 4 version requires that one edge of the phone slide into place, then the other edge snaps in. This has the advantage of the phone screen either facing the inner part of the holster, totally protected, or unprotected and exposed, but viewable to the wearer. I actually prefer the screen facing outwards, as it makes it easy to see who is calling, quickly check the time, read a text message, etc. The holster now also doubles as a stand, which has come in very handy for my wife and I to watch baseball games via the MLB At Bat app while dining out.

The case's built in screen protector has also been redesigned, incorporating a textured surface on the inside that eliminates any bubbling, but does not interfere in any way with the touch screen operation.

The Defender case, like prior models, is a multipart design. It includes an inner polycarbonate shell, which includes the protective screen cover, and a silicone skin which goes over the hard shell. The ports on the phone are well protected from dust and accidental exposure, small flaps easily peel back to expose the dock connector, headphone jack, and mute switch. The volume buttons on the phone are also easily accessible through the case.

As usual, Otterbox also has the Commuter and Impact series cases available for the iPhone 4, which offer less extreme protection for those who already pamper their phones, these models do not include a holster, but are still fairly rugged. All models are currently only available in black. Full details on these and other offerings can be found at

In summary, I think that every minor complaint I may have had regarding prior models have been addressed with this case; it works great with and without the holster, the mute switch is accessible, the phone can fit into the holster with the screen facing outwards, and the fit of the phone within the holster is excellent.

Posted by Jim at 3:17 PM | TrackBack