EmonPI

How to solve these types of errors in directory /etc/apt/sources.list.d/ ?

N: Ignoring file ‘mosquitto.git’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
N: Ignoring file ‘mosquitto-jessie.list.1’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
N: Ignoring file ‘mosquitto-jessie.list.3’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
N: Ignoring file ‘mosquitto_1.1.2.orig.tar.gz’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension

N: Ignoring file ‘mosquitto-repo.gpg.key’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
N: Ignoring file ‘mosquitto-repo.gpg.key.1’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
N: Ignoring file ‘mosquitto-jessie.list.2’ in directory ‘/etc/apt/sources.list.d/’ as it has an invalid filename extension
W: GPG error: http://ppa.launchpad.net trusty InRelease: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 03647209B58A653A

What is your setup and when do you see these errors?

When running the command sudo apt-get update

What system? EmonPi, EmonBase/EmonSD, Self install?

Also, how did those names come to be in /etc/apt/sources.list.d/ ?

Dave makes a good point.

All of the source list files in /etc/apt and /etc/apt/sources.list.d/
should have names ending in .list

The contents of those .list files should look similar to this:

deb http://ftp.us.debian.org/debian/ stretch main contrib non-free
deb-src http://ftp.us.debian.org/debian/ stretch main contrib non-free

deb http://ftp.us.debian.org/debian/ stretch-updates main contrib non-free
deb-src http://ftp.us.debian.org/debian/ stretch-updates main contrib non-free

deb http://security.debian.org/ stretch/updates main contrib non-free
deb-src http://security.debian.org/ stretch/updates main contrib non-free

deb https://packages.grafana.com/oss/deb stable main
deb https://repos.influxdata.com/debian stretch stable