How to set proxy in Ubuntu for all services?

Question

linux

Good afternoon!
The network uses an http proxy to access Internet resources.
Registered in the system settings of the network access to the proxy (address, port).
For apt-get to work, I added proxy settings in the apt config and set the http_proxy system variable.
But still, not all services work normally with the Internet. For example, add-apt-repository doesn't work.
In addition, it is very inconvenient in the browser to enter the login with the password from the proxy every time.
On Windows, I solve this problem by installing handycache. I specify the proxy settings in it, and I distribute the proxy outside through the local address without a login and password. In this case, you do not need to specify anything else anywhere.
Is it possible in ubuntu to write proxy settings somewhere in one place, including a login with a password, so that they do not have to be entered again and that all services that need the Internet use these settings?
Thank you!

Answer 1

Can be written to /etc/environment
http_proxy=...
https_proxy=...

Answer 2

There is also a button "apply for the entire system", + there is an opportunity to specify a config for a proxy - look on the network how to compose it, it is possible that he will enter a login with a password himself.