The Felix Fileinstall and Config Admin are two essential components of Apache Karaf runtime. I wrote about issues with array/list handling already twice. In 2015 and 2022. While earlier post was about syntax, later was about troubles with parsing of stored entries. Turns out, I’ve found a reason.

When it comes to handling of configuration updates from filesystem the Fileinstall is first in the queue to carry these into runtime. However recently I was again hit by its behavior. While earlier issue was solved just by making configuration read only, this time I wanted to keep it open for modifications. And problem was clear – I could write using square brackets (array) syntax, but I could not use regular brackets (collection) syntax. Over the journey I’ve found following.

Typed properties

Fileinstall embeds felix-utils which ship class named TypedProperties. This little lovely thing can distinguish typed and non-typed properties. Later ones are treated as strings. Turns out, decision is made based on regex, which does recognize [ a, b, c] syntax but does not accept ( a, b, c ). Issue known for 5 years – see FELIX-6042.

To make things worse, fileinstall relies on outdated felix-utils release till today. I was first hit by issue with fileinstall 3.6.6 back in 2020. But problem is still present in most recent release – 3.7.4. Why? Because it does rely on felix-utils 1.11.2 which miss this patch: https://github.com/apache/felix-dev/commit/2a8b4eba2fb99bfac727818f315ea190542c92e7.