Author Archives: hbanken

[OS X] Linux Open Directory and Mavericks clients: network accounts need GeneratedUID field

It has been quite some time since the last post on Open Directory on this blog, but I wanted to share something i found out about OS X Mavericks as a OD client. Let’s face it: running a non-Apple server for Apple clients is not your ideal, one-click-solution. It is not officially documented and the blogs are sparse, and more importantly: dated. Most how-to’s date back to 2009 or even older. My own write up dates back from 2009, rewritten in 2011.

A lot has changed since then. The server we tried to mimic was Tiger or Leopard and we tried to hook up clients of the same version. Apple continuously updates OS X and our consumers (or family members) want the latest and greatest features. These new versions like Lion and Mavericks brought some breaking changes. Think about technologies like using AFP in favor of NFS and the now new SMB2 that is not yet fully compatible with Samba, but also the discontinued Workgroup Manager (at least it is not shipped anymore) that I used to model changes from my old Snow Leopard server to my Linux OD’s autoconfig plist.

Mac OS X needs to repair your Library to run applications. Type your password to allow this.Some of my family members are experiencing a lot of trouble with their network home directories continuously disconnecting. I tried to overcome this issue by updating to the newest version of Netatalk (3.1) but this did not solve the problem. I also tried to disable Spotlight as is described [here](link needed). No luck. Looking through the log files I found some notice of “too many open files”, but searching this on the web I could not link it to network accounts with afp homes on linux servers.

Previously I did not wan’t our machines to keep local copies of the users home folders as I was worried about the home directories getting out of sync as this behavior can be very hard to explain to my users. When trying mobile accounts my own home folder got out of sync and it was a pain to merge everything back together.

This situation (with a continuously disconnecting home folder) however, was unworkable for the user and I decided to give it one more try. I went to System Preferences > Users and Groups and clicked the button to create a Mobile Account for my user. OS X logged out, and asked for the users password. After that: nothing. Inspecting the logs I found a warning about a missing GeneratedUID field in the user’s metadata. Looking at the LDAP schema I indeed found an apple-generateduid field that all of my users lacked. I added a binding for this field in my OD config and added the field to all my users. I then tried creating a Mobile Account and suddenly OS X started syncing the home folder! Success!

Not all files got synced immediately – the home folder of the user is 10G+ – and after login the home folder was incomplete. Just make sure you sync your users home directory completely or explain them their home still needs to be synced, otherwise they will be scared when they see their empty home directory.

HTML5 audio trouble

For a website of a music bind I’m currently developing, I needed a onscreen playlist controlled by javascript. The features are:

  • Save the songs in the same .playlist as the currently playing audio-tag.
  • Save current seek time of the playing audio-tag as it changes.
  • Save current song in the .playlist, so the index.
  • Restore the playing playlist on page load in a .playlist-player element if this exists.

This way the audio keeps playing when navigating through the website. When the player works, I’m also going to use AJAX to load the next page and push- and popState to update the URL, for a completely smooth audio experience.

So halfway during development suddenly the audio started crackling. Whenever I paused and played the audio again and again the crackling started to get worse. To test if this was a HTML5 thing I tried a YouTube video, but that audio also crackled. Googling for ‘Chrome audio crackling’ gave me some hints, but when I discovered the solution, that was no where near the solutions of the Google-results.

When developing in Chrome I also tried to view the player in an iPad Simulator (from XCode). This was not working and I decided to make things compatible later, and I forgot about having it open. So I restarted Chrome and the crackling was still there, I cleared cache, nothing worked. Then, I remembered the Simulator, closed it, and audio was back normal! The problem is probably with Core Audio being used by both Mobile Safari and Chrome, but I’m not sure.

You can test this by doing the following:

  1. Starting Chrome and Mobile Safari (in iOS Simulator) on the same OSX device
  2. Load a website using html5 audio-tags and start playing them on both browsers
  3. Toggle the play pause button a few times in Chrome, audio should become bad.
  4. Close the iOS Simulator and instantly audio goes back to normal in Chrome.

It will not always occur as I discoverd doing it the 3th time, but still: hope this helps anyone.

Code Reviews

Scrolling through my twitter timeline I read a tweet from Zef Hemel and found myself reading his blog the complete afternoon. One post that catched my attention was entitled “Never Commit to Master”.

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WhatsApp, running on your computer

WhatsApp in BlueStack App PlayerI previously wrote about playing WhatApp through VNC on your Mac, but this wasn’t useful if you didn’t have a phone near. Anyhow, there has been some development in the reverse engineering of Whatsapp and there are also some great emulators available right now, so I would like to introduce to you: Bluestacks running WhatsApp!WhatsApp on Bluestack

Warning: you can only have 1 device connected to WhatsApp at the same time. Once you have entered the verification code on your computer, you can’t use WhatsApp on your phone anymore until you reactivate WhatsApp on your phone. This can only be done 60 minutes after sending the previous verification code. A great way to circumvent this is by using a landline number, since you won’t be installing WhatsApp on your good old DECT-phone.

So how do you get this running yourself?

  1. Download the following files:
  2. Install Bluestacks by moving it from the dmg to your Applications folder (Mac) or clicking the installer (Windows).
  3. Start Bluestacks, this can take some time and at least my computer showed 50% CPU loads for a while.
  4. Install WhatsApp in BlueStack by running the follwing in Terminal:
    ~/Library/BlueStacks\ App\ Player/Runtime/uHD-Adb install \
  5. Start WhatsApp and set it up by entering your Country and Phone number, then wait till the time countdown is up. You will receive a SMS in the mean time, but you can’t enter this since – in Android – WhatsApp will handle this SMS automatically.  After the time is up, WhatsApp will offer to call you. Pick up your phone and enter the code the woman reads on your computer.
    WhatsApp sending SMS WhatsApp calling you
  6. Enter a name and your good to go. Enjoy!

WhatsApp contact list

[OS X] High process numbers

Ever experienced high process numbers (20k+) in Finder? That’s probably since some process keeps respawning over and over. Some launchAgents fail to start and launchtcl keeps trying to start them. This is filling your hard disk with logs and keeps your hard disk busy writing, preventing it to spin down.

12-07-12 11:11:25,732 (org.postgresql.postgres[66258]) Exited with code: 1
12-07-12 11:11:25,732 (org.postgresql.postgres) Throttling respawn: Will start in 10 seconds
12-07-12 11:11:34,034 (com.edb.launchd.postgresql-9.1[66265]) getpwnam("postgres") failed

You should probably fix the error that prevents the agent or daemon to start but thats depending on the kind of agent. In my case I didn’t need the agents that were spawning. I didn’t need a PostgreSQL-server and neither the Wiki-server OS X is providing, coming with all kinds of collab* processes. Please proceed only if you don’t need the agent you are going to remove, permanently!

So, how do you stop these annoying little agents? First determine the process-name. Then lookup the launchctl plist files:

$ sudo launchctl list | grep annoyingAgent

You can unload/remove this plist from launchctl by running:

$ sudo launchctl remove 'com.your.annoying.agent.plist'

Please check now that your computer is still functioning. Do this first, as you can return easily until now. Just replace the ‘remove’ with ‘load -w’ to re-add the agent.

When you reboot your machine the processes are sometimes coming back and to permanently disable them run:

$ locate 'com.your.annoying.agent.plist' | while read -r line; do sudo mv $line $line.disabled; done;

Control your home server

Last year I published my Ultimate Single Sign On tool for setting up a perfect Home Server. The work on this project is not yet done and I can use all the help you guys can offer me. Setup is easy: just use VirtualBox, Ubuntu Server and install after a git clone of git://

When you have this (or your own working LDAP server) up and running your users can login on Mac OS X and Ubuntu and can use their home directories and stuff. But they can’t change their credentials and user info, till now..

LDAP Control is a control centre for your Home Server where your users can manage their data (feature #2) but can also start and plan backups (feature #1), browse your families Address Book (feature #3), manage your favorite series and movies through the media centre (feature 4), and much more (when you guys help me).
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Git repository for ‘Single Sign On’-project

When I first made my installer for OpenLDAP I did this for my own convenience. But while doing so I realized the script could be useful for more people and I published it on my blog. Then it became big, and I invited Sean to write for my blog about this project. For Sean and you guys I just made a git repository on GitHub so anyone can edit the installer to be the best (and first) SSO-installer ever.

So please help this project and fork the project at

New Author, introducing: Sean

In the last few months this blog started to generate a lot more traffic than before. Mostly via the tweets from my fellow student (@veeence) but my site also gained a few returning visitors interested in the Mac server scene. As these folks started to test my scripts posted here they found found some bugs and posted some comments. One of them is Sean and today I’m announcing Sean as a new writer for this site.

Sean will mostly write about Mac server imitation implementations, complete with Single Sign On and Windows support. But of course he can write about whatever he wants if it’s only a little bit relavant for you guys!

So stay tuned and if you like the blog, subscribe for the RSS feed!

WhatsApp on Mac or PC

Update 13/01/13: run WhatsApp on your pc/mac without a phone/VNC!

WhatsApp is a fairly new App for multiple mobile devices. Due to the App Store, Android Market, etc. it grew huge in just a few months. Especially since people started to use them as a replacement for SMS chats and because your identity is based on your mobile number.

I think WhatsApp as a service has one disadvantage: it only works on mobile devices. Although it might be the reason it so popular. At the moment it’s a replacement for SMS and services that offer equal features like Google Talk work on multiple devices. So the service is not thought of as some kind of replacement for SMS. The nice thing is that every one who has WhatsApp has a smartphone and therefore can also download Google Talk apps should WhatsApp become less popular.

The nice thing of a full scale qwerty keyboard is that you can type way faster and therefore communicate faster. So the other day I was having a conversation on WhatsApp and messages where being send almost faster than they could be read. In order to keep up with the chat I really needed a full size keyboard. Then I came up with the following idea: install a VNC server on my iPhone and connect to it from my mac!

So here is the manual to do so:

  1. Jailbreak iPhone
  2. Install Veency
  3. Install VNC client on mac like “Chicken of VNC” or “JollysFastVNC“.
  4. Connect to your iPhone

Until somebody decides to write a app that can use WhatsApp as a server – I might get that idea in my head and end up writing it myself, so stay tuned – we’ll have to use this epic work-around or continue using our phones keyboard..

Want a free/open-source Apple Home Server?

When Apple introduced the Mac Mini server version nobody knew. When Apple discontinued the XServe people started thinking. When the changes for OS X Lion became public and OS X Server was merged into the client-version, everybody should have known. When the rumors came that Apple will stop using Samba and implement their own SMB2 server/client, I knew: Apple wants to give the world an alternative to Windows Home Server (WHS).

Whats in for me? Read more »