Set system proxy in Linux

setproxy.sh

#!/bin/bash

# CONSTANTS
# In case your proxy is without user and password just replace this line with
# HTTP:_PROXY="http://host:port"
# host is the proxy host. Ex: proxy.example.com or 192.168.1.50
# port is the proxy port. Ex: 3128 or 8080
HTTP_PROXY="http://user:password@host:port"
HTTPS_PROXY=$HTTP_PROXY

set_proxy(){
        echo "setting proxy";
        echo "setting SNAP proxy";
        sudo snap set system proxy.http=$HTTP_PROXY;
        sudo snap set system proxy.https=$HTTPS_PROXY;

        echo "setting APT proxy";
        sudo echo "Acquire::http::Proxy \"$HTTP_PROXY\";" > /etc/apt/apt.conf.d/proxy.conf
        sudo echo "Acquire::https::Proxy \"$HTTPS_PROXY\";" >> /etc/apt/apt.conf.d/proxy.conf
        sudo echo "Acquire::http::Proxy::mirror.uho.edu.cu DIRECT;" >> /etc/apt/apt.conf.d/proxy.conf

        echo "setting NPM proxy";
        npm config set --global proxy $HTTP_PROXY;
        npm config set --global https-proxy $HTTPS_PROXY;

        echo "setting GIT proxy";
        git config --global http.proxy $HTTP_PROXY;
}

unset_proxy(){
        echo "unset proxy";

        echo "removing proxy from SNAP";
        sudo snap unset system proxy.http;
        sudo snap unset system proxy.https;

        echo "removing proxy from APT";
        sudo echo '' > /etc/apt/apt.conf.d/proxy.conf;

        echo "removing proxy from NPM";
        npm config rm --global proxy;
        npm config rm --global  https-proxy;

        echo "removin proxy from GIT";
        git config --global --unset http.proxy
}

help(){
        echo type setProxy.sh on to put the proxy $HTTP_PROXY on snap, apt, npm and git;
        echo type setProxy.sh off to remove the proxy from snap, apt npm and git;
}


proxy(){
case "$1" in
        on) set_proxy;;
        off) unset_proxy;;
        help) help;;
        *) echo "only on or off supported"; exit 1;
esac
}

proxy $1