Why am I getting this error with apt-get in docker?

Question

linux

Good time of the day. When building the project, I get an error:

RUN apt-get clean  && apt-get update

E: Failed to fetch http://deb.debian.org/debian/dists/stretch/InRelease  Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?)
E: Some index files failed to download. They have been ignored, or old ones used instead.

Why am I getting an error?

Answer 1

Because translate.google.com!
In the same English and white it says: Unsigned file is invalid
You missed this step:
Add Docker's official GPG key:
$ curl -fsSL https://download.docker.com/linux/debian/gpg | sudo apt-key add -
$ apt update
https://docs.docker.com/engine/install/debian/