Distroless image internals

We used a Google "distroless" image as the base image on a go application deployment in a project a while ago. I never looked into what distroless really means, but I had a guess. I'm also curious to look under the hood of a docker image if they really are just merged archives.

Recently there was a "Docker without docker" blog post in Hacker news about how simple docker (or rather, OCI) image format is. Spoiler: an image is tar archives on top of tar archives. The post has also a detailed explanation of how to pull images from a container registry. I shamelessly took the image pull script they shared and modified it a bit to pull the static distroless image from the Google container registry.

The image is only one layer, and here is how it looks like after I extracted it and removed all the root level empty directories with all directories with at least one file expanded.

It looks pretty empty to me, and I suppose that's the origin of the distroless term! :thinksmart:

I compared it to an alpine image with the GNU/Linux diff tool, and the output is enormous.

Comments

I'm not a passionate developer

A family friend of mine is an airlane pilot. A dream job for most, right? As a child, I certainly thought so. Now that I can have grown-up talks with him, I have discovered a more accurate description of his profession. He says that the truth about the job is that it is boring. To me, that is not that surprising. Airplanes are cool and all, but when you are in the middle of the Atlantic sitting next to the colleague you have been talking to past five years, how stimulating can that be? When he says the job is boring, it is not a bad kind of boring. It is a very specific boring. The "boring" you would want as a passenger. Uneventful. Yet, he loves his job. According to him, an experienced pilot is most pleased when each and every tiny thing in the flight plan - goes according to plan. Passengers in the cabin of an expert pilot sit in the comfort of not even noticing who is flying. As someone employed in a field where being boring is not exactly in high demand, this sounds pro

Extracting object properties from an IFC file with IfcOpenShell

Besides the object geometry information, IFC files may contain properties for the IFC objects. The properties can be, for example, some predefined dimension information such as an object volume or a choice of material. Some of the properties are predefined in the IFC standards, but custom ones can be added. IFC files can be massive and resource-intensive to process, so in some cases, it helps to separate the object properties from the geometry data. IfcOpenShell is a toolset for processing IFC files. It is written mostly in C++ but also provides a Python interface. To read an IFC file >>> ifc_file = ifcopenshell.open("model.ifc") Fetch all objects of type IfcSlab >>> slab = ifc_file.by_type("IfcSlab")[1] Get the list of properties >>> slab.IsDefinedBy (#145075=IfcRelDefinesByType('2_fok0__fAcBZmMlQcYwie',#1,$,$,(#27,#59),#145074), #145140=IfcRelDefinesByProperties('3U2LyORgXC2f_hWf6I16C1',#1,$,$,(#27,#59),#145141), #145142

Hubristic developer

Almost half of any Finnish generation goes through a shared experience: the conscript army. An integral part of that experience is learning military slang, a set way people in the army talk. The stories told with said jargon often spread outside of the barracks. It is not uncommon to hear strangers bonding together over beers reminiscing and feeling nostalgic about freezing cold nights spent in tents. There is a similar phenomenon detectable among us coders. To be part of the coder tribe, there is at least one type of story that one must master. That is - of course - ranting about legacy codebases. "Can you believe how much of a mess the previous coders left? Hear, hear!" There is no better way to onboard a new team member than to blame some previous B-team for all the murky parts of the system at hand. This can be seen as harmless, a subject for a good meme . Rarely do we hold real grudges against "the legacy folk" and can be the best of friends in a social gather

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