Author: Alan Siu

Backing up database data from a Crypt server

This is really just a step-by-step version of what's available in the July 2015 update doc, which links to Django dumpdata and loaddata.

If you want back up your Crypt server database, this is how you can dump the data out:

docker ps
to find the name of your docker container, in case you forgot it? Let's just assume, for the next command, that the container's name is Crypt.
docker exec -it Crypt bash
This gets you to a bash prompt inside the Crypt docker container.
cd /home/docker/crypt/
Change to the docker crypt directory.
python manage.py dumpdata > db.json
Dump the data out into a .json file.
exit
Exit out of the docker container bash shell.
docker cp Crypt:/home/docker/crypt/db.json .
Copy the .json file to where you are outside the docker container.

If you want to get back into the docker container to delete the original .json (since there is no docker mv, only docker cp), you can do

docker exec -it Crypt bash
rm /home/docker/crypt/db.json
exit

P.S. Thanks to Graham Gilbert for the tip about not needing to chmod the manage.py file.

P.P.S. This data dump method will work regardless of whether you're using the built-in sqlite3 database or an external postgresql database.

Upgrading to High Sierra: “You may not install this volume because the computer is missing a firmware partition”

If you try to upgrade to High Sierra (macOS 10.13) and get You may not install this volume because the computer is missing a firmware partition when trying to select your drive to upgrade, it may be because you're upgrading on an OWC drive.

If you're using Munki, the error may appear in your /Library/Managed Installs/Logs/Install.log as Starting macOS install: FAILED: startosinstall failed with return code 243.

Previously, you'd have to physically swap back the OEM drive, and then put the OWC drive back again, but now OWC has its own firmware updater tool that fixes the problem:
Aura SSDs: Firmware Update (beta).

Parental Controls keeps blocking allowed apps

If macOS Parental Controls keep blocking allowed apps (both allowed through the checklist in System Preferences and through manually approving via password), deleting the account and recreating it may not be enough to fix the glitch. Instead, try recreating an account with a new name.

I've found Santa to block things more reliably (or not to block things you've allowed). You can block by certificate or (for Apple applications you'd need to do this), block by binary.

Handling cfqueryparam errors in ColdFusion queries

<cfqueryparam> is ColdFusion's way of fighting against SQL injection attacks. If, however, you just put <cfqueryparam> in your SQL or MySQL query, people entering the wrong type of input will get a server-side error message, which will make them think your website is messed up instead of realizing they put in the wrong type of input.

If you use <cfcatch>, be sure to specify that the type is database if you want to be able to display your own error message.

Here's an example:

<cftry>
<cfquery name="somequeryname" datasource="somedatasource">
SELECT somefield
FROM somedatabase
WHERE someotherfield = <cfqueryparam
value="#formname.someotherfieldname#"
cfsqltype="CF_SQL_INTEGER"
maxlength="12">
</cfquery>
<cfcatch type="database">
yoursupercoolandinformativeerrormessage
</cfcatch>
</cftry>

Preventing alarms from going off on MDM’ed iPads

If you have alarms set on iPads (either an actual alarm or an alarm from the "bedtime" portion of the Alarm app), you can't disable the alarm by blocking the app. All blocking the app does is prevent the user from launching up the app.

To prevent the alarm itself from going off, you have to block notifications from the Clock app.

Bulk-extracting and combining audio from .mov to .mp3

If you aren't able to use an audio recording app on your iPad for whatever reason and need to resort to using the Camera app to record audio (long story), you will get a bunch of .MOV files.

So I wrote up a script that employs ffmpeg to extract just the audio from each file in a subdirectory, and then combine the separate audio files from that subdirectory into one audio file.

Script here: ExtractCombineMOVtoMP3.py

CrashPlan 6.5 stuck on Connecting… and never times out

We had a couple of clients who would just never do an initial connection to CrashPlan after the upgrade from CrashPlan 4 to CrashPlan 6.5. But they would never time out or give an error message either.

Restarting the CrashPlan service didn't help. Restarting the computer didn't help. Uninstalling and reinstalling the client didn't help.

Turns out it if the detect-a-user script can't find a CP_USER_HOME, it will just keep trying to connect instead of erroring out. We modified our script, and now those clients are good (we did have to uninstall and reinstall the client after modifying the script, though).

P.S. Someone pointed out that I don't actually share the original or modified script. The point of this blog post isn't to say "Here's a script that works." There are lots of scripts that work. The point is more that if you're experiencing this issue ("connecting" and never timing out or providing an error message), you likely need to fix your script to output a CP_USER_HOME).

Considerations when upgrading CrashPlan with Munki

I had a great workflow for installing CrashPlan with Munki for older versions of CrashPlan (we were on versions 3 and 4 before).

We recently made the jump to CrashPlan 6.5, though, and that workflow no longer applies. Now you have to use a deploy.properties file instead of custom.properties and userInfo.sh files.

We had some added complications to our "upgrade" process, because our new CrashPlan server is a completely different server, and we weren't migrating everyone at once, so we couldn't just change the DNS to point to the new server. I'm not sure a jump from 4 to 6.5 would have been possible as just an installation upgrade anyhow.

So what were those complications?

  • We couldn't use an installs array any more to tell Munki whether CrashPlan was installed or not. Keeping the installs array would (without managed_updates) prompt users to upgrade to CrashPlan 6.5 or, worse, just upgrade them automatically (with managed_updates). So I changed CrashPlan 4 and 6.5 to use an installcheck_script instead.
  • Since CrashPlan 6.5 isn't just an update but an actual upgrade for us (think Microsoft Office 2016 vs. Microsoft Office 2011), it's a separate item in Munki altogether, which means we also had to remove the old version from the client's SelfServeManifest before installing the new version (otherwise, the old version would just reinstall).
  • Likewise, as part of the preinstall_script for 6.5, we had to invoke the /Library/Application Support/CrashPlan/Uninstall.app/Contents/Resources/uninstall.sh script to remove 4 first.
  • Lastly, we had to have a temporary place to hold the deploy.properties file before copying it to /Library/Application Support/CrashPlan—otherwise, the old installation of CrashPlan would somehow make it disappear or be unusable by the new installer. Not sure exactly what was happening, but it wasn't being recognized when just being delivered there directly as a payload. We also tried including the deploy.properties file in the .dmg itself, but that didn't work either (prompted for server and registration key).
  • Annoyingly, if you choose not to use SSO, you can't fully automate user account creation or sign-in, so some user interaction for the upgrade is required.

Ours may be a very niche scenario (upgrading from CrashPlan 4 to CrashPlan 6.5 and not using single sign-on), but in case anyone else is in that same situation and using Munki, maybe this blog entry can save you some time in planning your rollout.

Getting the Team ID of kernel extensions in macOS 10.13 (and higher?)

Why do you need Team IDs?

Beginning with macOS 10.13 (High Sierra), Apple is now blocking kernel extensions unless you, in recovery mode (or recovery mode–like environment), change the policy on the machine itself or use an MDM profile to approve certain KEXTs by Team ID.

How do you find these Team IDs, though?

sqlite3

One way is to install the KEXTs on a 10.13 machine, user approve them, and then check the sqlite database to see what the Team IDs are:

sqlite3 /var/db/SystemPolicyConfiguration/KextPolicy
SELECT * FROM kext_policy;

Here's an example of some of the output you might see:

EQHXZ8M8AV|com.google.dfsfuse.filesystems.dfsfuse|1|Google, Inc.|8
In this example, EQHXZ8M8AV is the Team ID and com.google.dfsfuse.filesystems.dfsfuse is the bundle ID.

You can use Control-D to exit the sqlite3 session.

Acknowledgements: Got commands from Enabling Kernel Extensions in High Sierra

codesign

Another way is to run this command on an existing bundle from the vendor:

codesign -dv --verbose=4 /PATH/TO/NAMEOFBUNDLE.app

For example, if you run

codesign -dv --verbose=4 /Applications/Google\ Drive\ File\ Stream.app
you should see in the output a line like
TeamIdentifier=EQHXZ8M8AV

This approach can be helpful in fringe cases (you just need the Team ID and not the bundle ID, which may be the case, and the KEXT you're looking for has an associated bundle you can run codesign on.

Acknowledgements: Got command from MunkiReport-PHP extensions module

Isn't there a list somewhere of all these Team IDs?

There is a list, actually. There's a spreadsheet that a bunch of Mac admins are sharing with each other. Unfortunately, at this point, it's a spreadsheet that anyone with the link can edit, so I wouldn't really count on that. At this point, I don't see anything malicious in there (and I haven't verified every single Team ID, of course), but I would probably play it safe and just get the Team IDs yourself. Chances are that you'll have to do it only once or twice a year at the most.