apt-get update not working on specific version

[minyoung90]

"tiangolo/uvicorn-gunicorn-fastapi:python3.9-slim-2023-05-22" version can do this command after "apt-get update",

RUN apt-get install netcat -y

but, "tiangolo/uvicorn-gunicorn-fastapi:python3.9-slim-2023-07-03" version can't that command with this errors

#0 0.388 Get:1 http://deb.debian.org/debian bookworm InRelease [147 kB]                                                                                                                                                                                                                   
#0 0.513 Get:2 http://deb.debian.org/debian bookworm-updates InRelease [52.1 kB]                                                                                                                                                                                                          
#0 0.559 Get:3 http://deb.debian.org/debian-security bookworm-security InRelease [48.0 kB]                                                                                                                                                                                                
#0 0.606 Get:4 http://deb.debian.org/debian bookworm/main amd64 Packages [8904 kB]                                                                                                                                                                                                        
#0 0.896 Get:5 http://deb.debian.org/debian-security bookworm-security/main amd64 Packages [47.3 kB]
#0 1.418 Fetched 9199 kB in 1s (7743 kB/s)
#0 1.418 Reading package lists...
#0 1.665 Reading package lists...
#0 1.915 Building dependency tree...
#0 1.972 Reading state information...
#0 1.974 Package netcat is a virtual package provided by:
#0 1.974   netcat-openbsd 1.219-1
#0 1.974   netcat-traditional 1.10-47
#0 1.974 
#0 1.976 E: Package 'netcat' has no installation candidate

[tiangolo]

You can probably try with the non-slim version, also probably better with a more recent version. This is based on the official Python image, which is based on the official Debian image. So, you could try to install the package on a pure Debian image, and once you make it work, you can copy that here.

---

Now, on the other hand... now that Uvicorn supports managing workers with --workers, including restarting dead ones, there's no need for Gunicorn. That also means that it's much simpler to build a Docker image from scratch now, I updated the docs to explain it.

Because of that, I deprecated this Docker image: https://github.com/tiangolo/uvicorn-gunicorn-fastapi-docker#-warning-you-probably-dont-need-this-docker-image