docker build -t metascan .
Sending build context to Docker daemon 1.306MB
Step 1/8 : FROM kalilinux/kali-rolling
latest: Pulling from kalilinux/kali-rolling
b8db5b66eb9d: Pull complete
Digest: sha256:d8f94cac6e035bf63c956d8663088ad335680bd4cd6b3a73226d8a656cafec46
Status: Downloaded newer image for kalilinux/kali-rolling:latest
---> 20d1b14b7bb9
Step 2/8 : RUN apt update -y
---> Running in 46d110c1e468
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
Get:1 http://kali.download/kali kali-rolling InRelease [41.5 kB]
Err:1 http://kali.download/kali kali-rolling InRelease
At least one invalid signature was encountered.
Reading package lists...
W: GPG error: http://kali.download/kali kali-rolling InRelease: At least one invalid signature was encountered.
E: The repository 'http://http.kali.org/kali kali-rolling InRelease' is not signed.
The command '/bin/sh -c apt update -y' returned a non-zero code: 100