This post was written with the assistance of AI.

1. Package Managers

1.1 apt

Debian’s repository configuration file is /etc/apt/sources.list.

# Uncomment to enable official repository
# deb https://deb.debian.org/debian/ trixie main contrib non-free non-free-firmware
# deb https://deb.debian.org/debian/ trixie-updates main contrib non-free non-free-firmware
# deb https://security.debian.org/debian-security trixie-security main contrib non-free non-free-firmware
# Comment to disable mirror
deb <mirror>/ trixie main contrib non-free non-free-firmware
deb <mirror>/ trixie-updates main contrib non-free non-free-firmware
deb https://security.debian.org/debian-security trixie-security main contrib non-free non-free-firmware

After changing the configuration, run:

# Refresh package index
sudo apt update

Some mirrors:

Mirror Debian URL
TUNA https://mirrors.tuna.tsinghua.edu.cn/debian

1.2 dnf

Fedora’s repository configuration files are /etc/yum.repos.d/fedora.repo and /etc/yum.repos.d/fedora-updates.repo.

/etc/yum.repos.d/fedora.repo:

# Fedora main repository
[fedora]
name=Fedora $releasever - $basearch
baseurl=<mirror>/releases/$releasever/Everything/$basearch/os/
enabled=1
countme=1
metadata_expire=7d
repo_gpgcheck=0
type=rpm
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

# Fedora debug repository, disabled by default
[fedora-debuginfo]
name=Fedora $releasever - $basearch - Debug
baseurl=<mirror>/releases/$releasever/Everything/$basearch/debug/tree/
enabled=0
metadata_expire=7d
repo_gpgcheck=0
type=rpm
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

# Fedora source repository, disabled by default
[fedora-source]
name=Fedora $releasever - Source
baseurl=<mirror>/releases/$releasever/Everything/source/tree/
enabled=0
metadata_expire=7d
repo_gpgcheck=0
type=rpm
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

/etc/yum.repos.d/fedora-updates.repo:

# Fedora updates repository
[updates]
name=Fedora $releasever - $basearch - Updates
baseurl=<mirror>/updates/$releasever/Everything/$basearch/
enabled=1
countme=1
repo_gpgcheck=0
type=rpm
gpgcheck=1
metadata_expire=6h
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

# Updates debug repository, disabled by default
[updates-debuginfo]
name=Fedora $releasever - $basearch - Updates - Debug
baseurl=<mirror>/updates/$releasever/Everything/$basearch/debug/
enabled=0
repo_gpgcheck=0
type=rpm
gpgcheck=1
metadata_expire=6h
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

# Updates source repository, disabled by default
[updates-source]
name=Fedora $releasever - Updates Source
baseurl=<mirror>/updates/$releasever/Everything/source/tree
enabled=0
repo_gpgcheck=0
type=rpm
gpgcheck=1
metadata_expire=6h
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-$releasever-$basearch
skip_if_unavailable=False

After changing the configuration, run:

# Refresh repository metadata
sudo dnf makecache

# Show enabled repositories and their baseurl
dnf repolist -v

Some mirrors:

Mirror Fedora URL
Aliyun https://mirrors.aliyun.com/fedora

2. Terminal

#!/usr/bin/env bash

# http_proxy is used for HTTP, and https_proxy is used for HTTPS.
# Use http://127.0.0.1:7890 as the example proxy address.
export http_proxy=http://127.0.0.1:7890
export https_proxy=$http_proxy

# Remove the proxy from the current shell.
unset http_proxy https_proxy

# Functions to enable/disable proxy.
enable_proxy() {
    export http_proxy=http://127.0.0.1:7890
    export https_proxy=$http_proxy
}

disable_proxy() {
    unset http_proxy https_proxy
}

3. Git

PROXY=http://127.0.0.1:7890

git config --global http.proxy "$PROXY"
# Only set github to use proxy
git config --global http.https://github.com.proxy "$PROXY"

# Show the current proxy configuration.
git config --global --get-regexp 'proxy'

# Use these two lines to remove the proxy.
git config --global --unset http.proxy
git config --global --unset http.https://github.com.proxy

#!/usr/bin/env bash

# srv_ip is a remote IP address, and local_ip is the local IP address.
srv_ip=192.168.1.2
local_ip=127.0.0.1
proxy_port=7890
proxy=

# Connect to the server proxy if available.
if nc -z "$srv_ip" "$proxy_port"; then
    proxy=$srv_ip
elif nc -z "$local_ip" "$proxy_port"; then
    proxy=$local_ip
fi

# Enable proxy if it works
if [ -n "$proxy" ]; then
    git config --global http.proxy "http://$proxy:$proxy_port"
else
    git config --global --unset http.proxy
fi

4. npm

#!/usr/bin/env bash

npm config set registry <mirror>

# Show the current registry.
npm config get registry

# List all configurations
npm config list
Mirror Registry URL
Tencent Cloud https://mirrors.cloud.tencent.com/npm/

5. Ruby

5.1 gem

#!/usr/bin/env bash

# Change the RubyGems source with gem sources.
# Add the <mirror> mirror and remove the official source.
gem sources \
    --add <mirror> \
    --remove https://rubygems.org/

# Only the mirror should remain.
gem sources -l

# Restore the official source.
# gem sources \
#     --add https://rubygems.org/ \
#     --remove <mirror>

5.2 Bundler

#!/usr/bin/env bash

# Set the global mirror for <mirror>.
bundle config set --global mirror.https://rubygems.org <mirror>

# Show the configuration.
bundle config list

# Check the active mirror.
bundle config get mirror.https://rubygems.org

# Remove the mirror.
# bundle config unset --global mirror.https://rubygems.org

Available mirrors:

Mirror RubyGems URL
TUNA https://mirrors.tuna.tsinghua.edu.cn/rubygems/

6. Docker

Docker in the Fedora repositories is provided by moby-engine.

#!/usr/bin/env bash

# Fedora repositories provide moby-engine to replace docker
sudo dnf install -y moby-engine

# Enable Docker at boot.
sudo systemctl enable docker

Docker image pulls are handled by dockerd, so configure the proxy for dockerd.

Add environment variables to docker.service:

sudo mkdir -p /etc/systemd/system/docker.service.d
sudo tee /etc/systemd/system/docker.service.d/http-proxy.conf >/dev/null <<'EOF'
[Service]
Environment="HTTP_PROXY=http://127.0.0.1:7890"
Environment="HTTPS_PROXY=http://127.0.0.1:7890"
EOF
sudo systemctl daemon-reload
sudo systemctl restart docker

Confirm the configuration:

systemctl show --property=Environment docker
docker info | grep -i proxy

Verify with hello-world:

docker pull hello-world

7. Desktop Environments: GNOME and KDE

Desktop Entry point Configuration
GNOME Settings -> Network -> Network Proxy Choose “Manual” and fill in HTTP/HTTPS/SOCKS
KDE Plasma System Settings -> Network -> Proxy Choose “Manually specify proxy settings” and fill in HTTP/HTTPS/SOCKS

8. Firefox and Chromium

Firefox. The GUI path is Settings -> General -> Network Settings -> Settings.

Chromium. Chromium only inherits the desktop system proxy.

9. Clash

Clash is no longer maintained.

Clash is a proxy client written in Go. The user configuration directory is ~/.config/clash/. The system-level configuration uses /etc/clash/.

9.1 User-Space Run

Put config.yaml in ~/.config/clash/ and start Clash with -d to specify the configuration directory:

mkdir -p ~/.config/clash
cp config.yaml ~/.config/clash/
clash -d ~/.config/clash

9.2 LAN Sharing

Enable allow-lan in config.yaml:

allow-lan: true
bind-address: '*'

bind-address set to '*' listens on all interfaces.