Manage your Macs with a Munki!

If you are not familiar with Munki you need to go take a look right now. It is possibly one of the easiest software management tools I have ever seen. It works on the same principal as Apple’s own Software Update system. You build a catalog of packages that you want installed on computers and it makes sure that software is installed and kept up to date. What munki provides beyond that is the ability to have each computer have it’s on manifest of software. A manifest tells it what software to install and what catalogs to pull from (i.e. production, testing, development, etc.).

Recently I spent some time getting our setup ironed out and better designed, and here is what I came up with. I’m not going to go through a step-by-step process for everything I did as this is a more open-ended install setup. Managing computers like this requires a bit more knowledge of the product itself. So you really should take a look at some of the munki documentation, particularly the getting started guide, as that will give you some understanding of the terms I will be using.

Setting up the munki repository

First off, I built a VM to run all this in. It is a simple Fedora 18 install with no GUI.  You can use any *nix flavor you want, but I am most familiar with Fedora. The server is named munki and has a few DNS aliases pointing to it as well, which I will get to in a moment. First off I installed netatalk to provide a few AFP shares, but for this use I primarily use it for a single share: the munki repository. I need to be able to manage the repository from my desktop Mac as that is where the command line tools are installed. Sadly there are no tools for managing the munki repository on *nix, only Mac. Since *nix does not have (good) support for things like Apple’s .pkg format, or .dmg even, it would be more trouble than it is probably worth to try and go for a pure *nix setup.

Anyway, I created a /var/www/munki/html folder that will store the repository and shared it with netatalk to just our “staff admin” users. This folder is also shared by apache under the hostname munki.mydomain.com. Next mount the share on the Mac and initialize the repository (or in my case, copy my existing repository to this location). For this I use MunkiAdmin, which provides a nice GUI for working with the munki repository. Now with your repository created you can start building up your packages, catalogs, manifests, etc. I can’t help you with that specifically, but later on I will give you an idea of how we structure our manifests.

One thing to note with this is that I put the /var/www/munki/html folder as it’s own hard disk volume in the VM.  Currently my repository is 5.7GB, so to give myself some growing room I created the hard disk as an LVM of 15GB. Doing an LVM means I can increase the size of the hard disk without rebuilding everything.

Setting up your web interface

The same guy who wrote munki also wrote munkiwebadmin, which is a web interface to munki. Primarily it is for monitoring and seeing status information, but you can do some basic manifest editing. That is handy for moving something from one manifest to the other, but since you can’t upload new packages you will probably do most of your true admin stuff in MunkiAdmin. However, I found munkiwebadmin (yes I know, sorry for the confusing names here) to be most powerful in its reporting abilities. I followed the install instructions here with a few minor changes. I created my virtual environment in /var/www/munki, so the final path became /var/www/munki/munkiwebadmin_env. You will also be pointing your repository to /var/www/munki/html so it can find everything. In Apache I setup a new virtual host of munkiadmin.mydomain.com that will handle the WSGI stuff and access to the website and obviously also setup a DNS alias to point to the server.

For the install I used MySQL instead of the default SQLite. The reason for this is that I also installed phpMyAdmin so that I can get CSV exports of the inventory data from munkiwebadmin. We only keep computers for 5 years and then they get sold off, usually to staff at the going eBay price minus a little. Using this list lets me sort the computers by how old they are and then take the bottom 1/5 of the list as the computers to be replaced this year. I can do the same in an SQLite database, just not as easily since that requires logging in and running some command line commands and then copying files across the network.

I also had to make 2 small changes to the source code with you can find here and here. Hopefully by the time anybody works on this these two issues will be fixed. Basically those two changes make it so the manifest list does not include the files created by netatalk and also addresses an issue when using MySQL as your database.

Finally, I built a package that contains the 3 scripts from munkiwebadmin. For building custom packages I use an app called Packages, it is simple and quick. The reason I build a separate package (which I called munkiscripts version 1.0) is that it lets me easily go back and update just the scripts. For example if I decide that I want to have munki do some other pre/post-flight operations I can push out a new munkiscripts package with those updated scripts. In fact I have considered doing this to have the postflight script scan the console log for disk I/O error messages and notify me and potential hard drive failures. Anyway, all I have to do is bump the version number and import it into munki and munki will install the new scripts on the next run. So yes, you will want to add this package to your repository.

Setting up your own SUS server

The last thing I wanted to do was have this server manage all software updates. Currently I have a Mac server doing this, and wasting a ton of disk space at the same time. There is an “application” called reposado that is basically a few linux scripts that handle downloading software updates from Apple and mirroring them locally on your server. I basically followed the getting started instructions. I created a new set of folders for reposado in /var/www/reposado/html and /var/www/reposado/metadata and pointed the configure command at those 2 folders.

I also created a 3rd hard drive in the VM and mounted it in /var/www/reposado. While the munki repository you could have as part of your room VM disk, I recommend the SUS volume be a separate disk for one very specific reason.  It’s big and can be downloaded again. At the time of writing this my entire SUS repository is 100G and will only get bigger as time moves on. The disk that backs this volume is set to not be backed up in VMware. If I lose it, I just run the sync command again.

So anyway back to reposado, basically follow the instructions and create an apache share for /var/www/reposado/html. In my case I created yet another virtual host of reposado.mydomain.com to handle these requests and setup the DNS alias. I tend to do things this way as it makes it easier to migrate things from one server to another. For example if I later decide to move reposado off the munki server I just have to update the DNS entry, not every client. Once reposado is setup, run the sync tool and go get a coffee, or lunch, or if you have a slow internet connection maybe a weekend. Like I said, 100GB.

Configuring Clients

We have all this great stuff happening on our server, but nothing is talking to our server just yet.  Three things need to happen to get all your clients integrated happily.

First we need to get munki installed on each client workstation. The software needs to be installed (which is pretty straight forward) and it then needs to be configured to point to your repository. You can do the latter any way you want. You can run a terminal command to set the properties, managed preferences, whatever. I use managed preferences so that I can easily change settings per-client. Munki install docs talk about various ways to do this. Your repository URL will be something like http://munki.mydomain.com.

Second we need to run munki so that it downloads all initial software, including the scripts. This will either happen after about an hour or you can use a terminal command to have it check now. I recommend doing a “check now” on a few clients just to be sure everything is working the way you expect, that way you are not waiting for hours to find out something was configured wrong.

Finally you need to update the software update catalog URL used by Apple. Reposado has some examples of URLs you will be using, yours will be something along the line of http://reposado.mydomain.com/content/catalogs/others/index-mountainlion-lion-snowleopard-leopard.merged-1.sucatalog for Mountain Lion (others will be similar). I use a modified script that runs as a login-hook I found here. Scroll down a few comments to one by the user feyd, that is the one you want (at-least as a starting point).

Reboot just to make sure everything is picked up. Wait a little bit and you should start seeing data populate in munkiwebadmin. Also you can verify that your clients are pulling from your SUS because the Software Update app (or App Store) will tell you where it got the update from, so it should have your reposado URL listed.

Example manifest structure

So the way munki handles everything is by manifest. You can either set a specific manifest or let munki use a default one (computer name, serial number, “site-default”, etc.). But each manifest references packages to be installed/updated/remove as well as catalogs to pull those packages from. It can take some work to get things sorted out in an order that works well. I can’t say what I have is best but it works for me.

First, the reason I ended up with this layout. We have basically 4 different computer groups. Realistically 95% of our workstations are in 2 of those groups. We have a standard install group that every computer gets (this would include computers that are head-less, or otherwise non-user centric). Then we have a staff group that is basically office computers which have people sitting at them. On top of that we have 2 speciality groups: Communications/Graphics/Video Department and Teaching Pastors. Each of those last 2 exist for one very specific reason. The first gets the latest version of the Adobe suite while the others get an older version (saves us some money doing it this way). The latter group get a different set of installed modules for some Bible software we use, so the staff gets the packaged version and those 4 computers (currently) get a manually installed version.

Now, a quick bit of understanding for how manifests work. A manifest references catalogs to determine which version of the package to install. So you might have a production catalog and a testing catalog. You put the upgrade in the testing, roll it out to your “early adopters” group and then when you are satisfied there are no problems move it to your production catalog. A manifest can also include other manifests, however, if an included manifest references any catalogs those catalogs will be search first. So for example, my early adopters manifest is called infotech and everybody else uses staff. The infotech manifest includes staff. infotech also references the testing catalog. If the staff manifest references the production catalog then the production catalog will always be checked first, even if the software is mentioned directly in the infotech catalog.

What I have adopted to resolve this is a “split manifest” system. So these are the manifests I currently have:

  • standard_software – Lists all the software, but no catalogs.
  • standard – Includes standard_software and references the production catalog.
  • office_software – Lists all the software for office computers, but no catalogs.
  • staff – Includes the office_software and standard_software manifests, references production catalog.
  • infotech – Includes office_software and standard_software manifests, references testing and production catalogs.
  • graphics – Includes office_software and standard_software manifests, references graphics and production catalogs. (graphics catalog has the newer version of the Adobe suite)
  • teaching – Includes office_software and standard_software manifests, references teaching and production catalogs. (teaching catalog has the different version of the Bible software)

Using managed preferences, it is fairly easy and straightforward to assign computers to various manifests and change them back and forth, though bear in mind munki may get confused by changing people’s manifests dramatically. i.e. if I install a computer as a teaching computer and then switch it to a staff computer, it will stick with the advanced version of the Bible software unless I manually remove it and then munki will re-install the correct version.

So basically ,when I say “split manifest” above what I mean is one manifest to hold the package names and another manifest that the computers point to. So all the *_software manifests are what contain the software, but the computers point to standard, staff, infotech, and graphics. That allows me to easily create a graphics_testing manifest that one computer points to which includes the same child manifests but references the testing catalog first so it gets the updated version.

Apple Software Updates

One other thing munki can do is install Apple Software Updates as well. This is useful if your users do not have admin accounts on the computer, and thus are unable to install the updates themselves. I have not yet rolled this out. It seems like it is not 100% stable from watching the discussion mailing lists. I do not mean stuff is broken and computers break, just that the update process is based upon a “apple does their own thing, we think we have figured it out” principal. So occasionally Apple releases an update that behaves strangely because it doesn’t fit into the mold of “we have figured it out” just yet and the mold has to be slightly modified. I think the worse I have seen is updates that keep showing up over and over again.

There is lots of documentation for how to turn this on (and off) so it may be worth your attention.  I will be looking at it again once I have more time, but for us it is not a critical issue since most of our users have admin access on their computers so they install their own updates.  As we move forward and (possibly) take that away this will be a bigger issue so we will look into it more.

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