Fun with CMake version ranges

Since release 3.19 CMake allows to specify a range in find_package() calls:

find_package(Dummy minVersion...maxVersion)

Although currently not much find modules support version ranges one might want to set the upper end to a maximum version the code is compatible with. This can be seen as a safeguard against breaking changes in an unknown future major version.

Let say we have a package “Dummy” whose major versions 1 and 2 are known to work with our own code. One might be tempted to specify the version range like the following:

find_package(Dummy 1...2)

This works well with 1.0.0, 1.5.0 or 2.0.0, but will break with 2.0.1 or 2.1.0.

Instead use the following syntax to include major versions 1 and 2:

find_package(Dummy 1...<3)

But why so?

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SWAG and WordPress in a subfolder

Desired setup

A SWAG reverse proxy should forward requests to WordPress running in the official wordpress docker image. The URL which is served by the reverse proxy is not the domain root, but a subfolder “blog”:

What does not work

Letting the docker image itself serve wordpress in the root folder and write some clever proxy / rewrite rules. At first it seems to work, but when it comes wp-admin URLs like a magic redirection happens to which points to outside the WordPress installation.

Fiddling around with RELOCATE, WP_HOME and WP_SITEURL does not solve the problem.

As it turns out WordPress needs to know the fact that it is installed in a subfolder, quote:

What you’ll want to do is run your WordPress container with WORKDIR set to /var/www/html/lab so it knows it is in a subdirectory and acts accordingly.

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Howto backup hosted nextcloud

In a hosted environment you ususally don’t have direct access to the database where calendars and contacts are stored.

And even when the provider has some sort of backup

  • you don’t really own it, because you can’t download it
    • e.g. you don’t can’t just migrate in case you are locked out for some reason
  • its an “all or nothing” story when it comes to restores
    • the whole instance/account is reset to some point in time
    • any change in between the last backup is effectively overwritten


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Wie man http-Server unter Python mockt

Führt der eigene Code http-Calls aus, z.B. um Dateien von einem externen Server runterzuladen stellt sich die Frage nach der Testbarkeit. Idealerweise ist der Code so aufgebaut, daß er nicht direkt von einer http-Library abhängt und man entsprechende Calls mocken kann. Ist dies nicht einfach möglich, kann man den in der Standarlibrary eingebauten http.server als localhost-Gegenstelle für Tests verwenden.

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