Friday, April 17, 2015

run cygwin sshd under SYSTEM user - The CYGWIN sshd service on Local Computer started and then stopped. Some services stop automatically if they are not in use by other services or programs

I got this error when trying to switch cygwin sshd to run as windows SYSTEM user. This is a need if you want to allow cygwin to interact with graphical applications.
The CYGWIN sshd service on Local Computer started and then stopped. Some services stop automatically if they are not in use by other services or programs
The first thing to do is to look into the sshd logs:
$ tail -10 /var/log/sshd.log
/var/empty must be owned by root and not group or world-writable.
The reason for this error is the fact that SYSTEM user (look upper case) is not the owner of /var/empty. The exact reason why this error happens is explained here. So the solution is simple:
$ chown SYSTEM /var/empty
Even though I went pass this issue I later realized there was no way to run desktop applications remotely using this method as explained here and here.

Monday, April 13, 2015

dockerized mediawiki 1.25 upgrade

The latest version of mediawiki comes with VisualEditor which marks the beginning of real wiki visual edition thanks to the use of node parsoid project. This is a radical change when we compare with the former CKEditor which would add a lot of html tags to your wiki markup. With Visual Editor we get plain wiki markup that can be edited by those who do enjoy the keyboard more than the mouse ;-)

Here is a partial docker guideline that can be used to install this latest version.

Friday, March 27, 2015

When my Apple MAC notes disappeared ...

Several posts on the web suggest to open the different files you see in ~/Library/Containers/ renaming them to use the ".html" extension, however I was able to recover them after deleting the ".storedata-wal" and ".storedata-shm" files.

Before proceeding please make a copy of the whole Notes directory. The file(s) with extension ".storedata" is/are what you want to keep and in fact these are sqlite files so you can open them, see the schema and inspect tables with the sqlite3 command.

BTW this happened to me after I started playing with iCloud. My iPhone and MAC notes were not synchronizing anymore and after finding that the iPhone notes were the ones in iCloud I started playing with iTunes and Notes accounts' settings to end up losing my MAC notes and getting those from the iPhone locally.

Saturday, March 14, 2015

Docker - izing real life production services in Ubuntu

I plan to publish several real life production showcases on docker usage. Instead of using the classical posts on this blog I will go this time with github documentation as I will be posting some working code in there.

If you are new to docker you might check it out as there is an initial section to get to speed with docker. If you are well versed with docker please do so as well, to get it right as usual I need your criticism.

Tuesday, March 10, 2015

host command returns correct IP but SSH still goes somewhere else!

When /etc/hosts overrides DNS strange things might happen like in this case today when someone would ssh into a remote machine but end up still in his own host.

You better run ping and host and if there are not the same then look for the domain in question inside /etc/hosts.

Friday, February 06, 2015

Setting DISPLAY variable to avoid No protocol specified Error: Can't open display: :# Selenium UnknownError: unknown error: Chrome failed to start: exited abnormally

If Selenium server cannot open the current display the client will fail with an error similar to "UnknownError: unknown error: Chrome failed to start: exited abnormally". This is a common issue many people ask about when they try to either run X applications (like tests against selenium in a remote server) remotely or when they are logged in via VNC, XRDP etc. Basically the DISPLAY variable is assigned to the local terminal console and not really to the remote session. You need to find the proper DISPLAY variable for your remote session in order to resolve this problem.

Setting DISPLAY variable will avoid the typical problem "No protocol specified Error: Can't open display: :#" where # is usually 0.

If this variable is set incorrectly your session will have no access to run X applications in the visible display. Perhaps the fastest way to find out if your DISPLAY is correctly set is to run the xclock application. The commands below should be self explanatory about how it fails and how it should be corrected at least in Debian/Ubuntu: So all you really need to do in order to make sure your selenium server spawns the chrome browser successfully is to set the DISPLAY variable to the correct value. Keep that in mind specially after restarting.

Saturday, December 27, 2014

ITPalooza Kanban and Continuous Delivery presentation

This was definitely a great event to share Kanban and Continuous delivery experiences with other agile practitioners in South Florida. I thank IT Palooza and the South Florida Agile Association for the opportunity.