Unable to run apt-get update when using oryx/python:3.10 due to GPG NO_PUBKEY error

[ssanderlin]

Bug Report

• At what date and time did you most recently experience the problem?
  2/12/2024 @ 1150 Eastern

• Where did you experience the problem? E.g. Azure Web Apps, Azure Functions, Azure Container Registry, or offline use.
  Building Dockerfile that's using mcr.microsoft.com/oryx/python:3.10 as its base image

• If your repo is publicly available please share its URL:
  N/A

• What happened?
  During a build of a Dockerfile that uses this image as its base, I received this error during the apt-get update step:

GPG error: https://packages.microsoft.com/debian/12/prod bookworm InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF

• What did you expect or want to happen?
  To be able to run apt-get update during a build that uses this oryx/python:3.10 as its base image without receiving this error.

• How can we reproduce it?
  Create a docker file with the following contents:

FROM mcr.microsoft.com/oryx/python:3.10
RUN apt-get update

• Do you have log output? Please include between the backticks:

[+] Building 4.9s (6/13)                                                                                                                                                                             docker:default
 => [internal] load build definition from Dockerfile                                                                                                                                                           0.0s
 => => transferring dockerfile: 640B                                                                                                                                                                           0.0s 
 => [internal] load metadata for mcr.microsoft.com/oryx/python:3.10                                                                                                                                            0.2s 
 => [internal] load .dockerignore                                                                                                                                                                              0.0s
 => => transferring context: 207B                                                                                                                                                                              0.0s 
 => CACHED [1/9] FROM mcr.microsoft.com/oryx/python:3.10@sha256:f2f9bbd0cfb0934fef30bbfbf404cb96570a6de2238a987337e35aa3e60918f4                                                                               0.0s 
 => [internal] load build context                                                                                                                                                                              0.1s 
 => => transferring context: 7.33kB                                                                                                                                                                            0.0s 
 => ERROR [2/9] RUN apt-get update                                                                                                                                                                             4.6s 
------
 > [2/9] RUN apt-get update:
0.716 Get:1 https://packages.microsoft.com/debian/12/prod bookworm InRelease [3617 B]
0.821 Err:1 https://packages.microsoft.com/debian/12/prod bookworm InRelease
0.821   The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF
0.889 Get:2 http://deb.debian.org/debian bookworm InRelease [151 kB]
0.947 Get:3 http://deb.debian.org/debian bookworm-updates InRelease [52.1 kB]
0.998 Get:4 http://deb.debian.org/debian-security bookworm-security InRelease [48.0 kB]
1.082 Get:5 http://deb.debian.org/debian bookworm/main amd64 Packages [8786 kB]
2.206 Get:6 http://deb.debian.org/debian bookworm-updates/main amd64 Packages [12.7 kB]
2.236 Get:7 http://deb.debian.org/debian-security bookworm-security/main amd64 Packages [137 kB]
3.827 Reading package lists...
4.515 W: GPG error: https://packages.microsoft.com/debian/12/prod bookworm InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY EB3E94ADBE1229CF
4.515 E: The repository 'https://packages.microsoft.com/debian/12/prod bookworm InRelease' is not signed.
------
Dockerfile:6
--------------------
   4 |
   5 |     # Install GCC for pyodbc
   6 | >>> RUN apt-get update
   7 |     RUN apt-get install -y gcc
   8 |
--------------------
ERROR: failed to solve: process "/bin/sh -c apt-get update" did not complete successfully: exit code: 100