opsiconf 2018

It is a week already since the first ever opsiconf took place in Mainz, Germany.

I may be a bit biased as I was involved in some smaller parts of the preparation but my focus before the conference was to have a stable release for opsi 4.1 out. However I don't think that you had to be involved to have a good time.

The thing I enjoyed the most were the discussions with various opsi users. I got a lot of input and was able to help users with my knowledge. There was a great feeling of community - it didn't matter if you are an opsi veteran or just starting with opsi - everyone was welcome.

It was great for me to hear how many people actually use the API to automate their workflows with opsi. There have been lighting talks from users showing how they integrated opsi into their system which I found very inspiring!

It sure boosts my wish to improve the API documentation to make the usage simpler - especially for newcomers. If you have any questions now don't hesitate to post them in the fresh opsi development subforum.

The conference was also used to announce the public repositories for opsi on ARM devices. Head over to the announcement in the forums to read more.

I am really happy with how everything went. There is still a bit of room for improvements but it was a good debut in my eyes. If there will be another conference (I hope there will be) I'd love to see more talks given by users next time.

PS: This wasn't the first opsi-centered conference. There hase been the opsi4instituts conference in 2017. Our community sure is busy :)

News from the Machine Room - January 2018

It's been quite busy weeks from the start of the year on.

A major opsi release is lurking around the corner and even though the development is mostly done there are a lot of other things to do in preparation of it. The most obvious one is probably improving the documentation for the release.

But for me these weeks have also been filled with writing a lot of small utility scripts for our internal use. Those batteries included did help me a lot for this!

For the next week I expect to work on some finishing touches in the documentation and tweak our OBS build configuration.

opsi-script: Checking for opsi 4.1

Since this week public repositories for opsi 4.1 are available and now is a good time to prepare for the switch to opsi 4.1. If you are using opsi to also manage your opsi servers there is a chance that you may want to distinguish between servers running opsi 4.0 and opsi 4.1.

This was the case as I was working on some opsi script that makes use of the new .repo file feature in opsi 4.1 for easy configuration of opsi-package-updater.

In case the script is run on a server that does not support this feature I wanted to abort with a meaningful message.

This is what I came up with:

if "0" = getLastExitCode
    message "Doing some awesome opsi 4.1 stuff..."
    isFatalError "Only usable on opsi 4.1 or newer."

set -x
export PATH=/sbin:/usr/sbin:/usr/local/sbin:/root/bin:/usr/local/bin:/usr/bin:/bin
python -c "from OPSI import __version__ as v; print(v)"
exit $?

Improving our integration tests

In the last weeks I focussed on our integration test environment. For opsi 4.1 we are increasing the amount of tests we run because in addition to the tests descriped here we added automated migration tests. All these tests should not only be reliable but they also should be fast so that it is possible to run them often.

One downside of our test implementation was that it spent a lot of time in sleep. If we know a reboot would happen then we inserted a sleep 120 to wait 120 seconds and then hopefully the machine was up. Two minutes are a lot of time but sometimes during heavy load that wasn't enough for the machine to be up and accessible. So in some places this got increased to 180 to make really, really sure that the machine could be reached. This made tests a little bit more reliable but also slower. The overall runtime for one of these tests is usually somewhere between two and four hours. Three minutes do not seem like much but there is usually more than one sleep in each test.

So I went on to replace all the sleeps with something better. As mentioned before the sleeps are usually inserted when we wait for a port being reachable. This usually is SSH or opsiclientd which we then use for further work.

My attempt was to write a small Python script that does the waiting for us. Connection attempts are made until the port becomes reachable with a short delay inbetween checks. Once a port is reachable it exits. If a connection can not be made after five minutes it is assumed that something went wrong and the script ends with an non-zero exitcode. The exitcode helps in using this script inside our jenkins stages as this marks the step as failed.

The script does have some tricks though. If a port is reachable right away it will exit right away. The script also understands different kinds of waiting. It may wait for a port to come up, a port to come down or a reboot to happen (port goes down and then comes up again).

With the script in use we managed to reduce the overall runtime by some minutes. Not totally overwhelming but in the end every minute counts. In addition this also improves the reliability of our tests. There is another neat advantage: most of the tests are implemented as functions and the changes made for the tests of opsi 4.1 also effect the runtime of our opsi 4.0 tests.

Using jq to work with JSON

I often see processing of JSON on the shell through tools like grep and awk. Sure, this works but usually it depends on the output having only one item per line and not having the keywords you are grep'ing for in other places.

So I was very delighted to learn that there is a better way through the commandline tool jq.

With jq you can filter, slice and alter JSON. And you get some highlighting of the output which makes it nicer to read than plain text!

Here are two small examples I tried out today to process output from opsi-admin:

opsi-admin -d method host_getHashes | jq '.[] | .id + ": " + .lastSeen'

This will list all your clients along with the time they have been last seen. The output on my test machine looks like this

"vtest16r.uib.local: 2013-09-08 21:28:50"
"vtest18-w2k-r.uib.local: 2008-05-24 17:58:35"
"zedach.uib.local: 2011-01-19 15:47:18"

And to see what installation status the products on your clients have you can use this snippet:

opsi-admin -d method productOnClient_getHashes | jq '.[] | "On " + .clientId + " the product " + .productId + " is " + .installationStatus'

Again with some example output:

"On pcbon4.uib.local the product xnview is installed"
"On fscnoteb1.uib.local the product xpknife is unknown"
"On vtest16r.uib.local the product xpknife is installed"
"On fscnoteb1.uib.local the product yed is installed"
"On hpnoteb1.uib.local the product yed is installed"
"On pcbon4.uib.local the product yed is installed"

Creating new JSON data is also possible:

opsi-admin -d method productOnClient_getHashes | jq '.[] | {hostId: .clientId, productId: .productId, status: .installationStatus}'

This return something like the following (look ahead: no JSON list but multiple standalone dictionaries instead):

  "hostId": "vmex12w10x64c.uib.local",
  "productId": "winscp",
  "status": "installed"
  "hostId": "vmex12w10x86.uib.local",
  "productId": "winscp",
  "status": "installed"

If you want to know more I'd suggest to start with the documentation. If you do not want to install anything on your machine there even is an online version to play with.

Smoother transition to opsi 4.1

Work towards a public opsi 4.1 release is making progress. Today's release has brought us a small step closer to a seamless migration from 4.0 to 4.1.

The release includes an opsi-atftpd which provides opsi-tftpd and the updated opsipxeconfd, opsi-depotserver and opsi4ucs all require this. This makes it easier to switch to a different tftpd without requiring any further user interaction.

opsi 4.1 will be released in a separate repository. Our current migration path is adding the new repository and then run apt, yum or zypper with their upgrade options to migrate to the new version. To finish the migration you will have to run opsi-setup with the update parameter for the backends you use and this is it.

Reproducable Debian Packages

If you are following tech news you probably read that this week Debians efforts in having reproducible builds resulted in making it a policy that packages should be reproducible. In short this means that given the source could anyone should be able to reproduce the resulting packages that are distributed through the Debian repositories.

I think this is very good!

Over at the opsi.org GitHub page you can have a look inside the repositories and you will find all parts that are needed for building. Whenever we release a new version the commit used for that package receives a tag. This is useful not only in pinning down changes between different versions but also if we want to provide patches for specific versions.

Regarding git we still have some repositories left to migrate from Subversion but I am confident to get this tackled until the end of the year. Then everything will be accessible at one location - again.

News from the Machine Room - Summer Season 2017

This is just a small update from the machine room.

Summer season has hit the office and many of our co-workers enjoy their holidays. The developer team is helping out in the support to not have any shortcomings for our customers.

Other than that we are in preparation of a new release for opsi 4.0 that will bring support to some newer distributions - Debian 9, openSUSE Leap 42.3 and Univention Corporate Server 4.2.

Unfortunately this delays the release of opsi 4.1. The upside is: we can have support for these distributions right at the release. While some preparations still need to be done we are making good progress.

I hope to be back soon with longer posts. Until then: enjoy your summer!