# DIY Local Proxy Cache

Proxies, or proxy servers, are computer programs that act as an **intermediary** between the **user** and the **destination server**. One often uses a proxy server to modify the way a user accesses a website, to redirect the user to a different website and so on.

## In This Tutorial
We will be using `proxy.py` to setup a proxy server to **cache** and serve content from the internet. 

>Caching is the process of storing the content of a website in a local cache to speed up the loading of the website.

Imagine you have a lot of devices on the same network. Now if one device visits a website and the **website is slow to load**, without a proxy all the other devices will have to wait for the website to load.

With a proxy this issue can be **minimized due to the caching of the website**. The proxy server coordinates with the source server to cache documents such as files, images and web pages.

## Prerequisites
⚠️ If you are using a **Mac** system, the Docker image is broken due to incompatibilities with [vpnkit](https://github.com/moby/vpnkit/issues/469). However you can use [**Homebrew**](https://github.com/abhinavsingh/proxy.py#using-homebrew) to install it.

Having a Raspberry Pi is **not** a requirement for this tutorial. Although if you have a Raspberry Pi you can use it to setup a proxy server.

We will be using **Docker** to setup the proxy server.

Install Docker from here - [Docker Engine](https://docs.docker.com/engine/install/)

One command is all it will take to setup this proxy.

```bash
docker run -d --restart unless-stopped -p 8899:8899 abhinavsingh/proxy.py:latest --plugins proxy.plugin.CacheResponsesPlugin --hostname 0.0.0.0
```

**Explanation**

- `docker run` - Starts the proxy server.
- `-d` - Runs the proxy server in the background aka detached mode.
- `--restart unless-stopped` - Restarts the proxy server if it is stopped automatically, however if stopped automatically it will stop.
- `-p 8899:8899` - Sets the port to 8899 and expose the internal port of the Docker container to the internal network.
- `abhinavsingh/proxy.py:latest` - The proxy.py image.
- `--plugins proxy.plugin.CacheResponsesPlugin` - The plugin to cache responses as mentioned in the documentation [here](https://github.com/abhinavsingh/proxy.py#cacheresponsesplugin).
- `--hostname 0.0.0.0` - Sets the hostname to 0.0.0.0, which means that the proxy server will be accessible from any device on the network. This is important.

💡If you want to check out more about Docker commands, you can check out my article [here](https://blog.anjann.dev/docker).

Your proxy is now running on port **8899**.

That's about it! You can set your device (recommended) or browser to use the proxy.

## Setting It Up

Set your proxy IP to the IP address of the **device the docker container is running on**.

If you are running the container on a Mac or Linux system use `ifconfig` to get the IP address of your system.

If its Windows then `ipconfig` will print the IP address.

⚠️ Most of the times the DHCP server on your router should assign your device a static internal IP address, however if it doesn't, change your device settings from DHCP assignment to static assignment.

### Linux
If you have a Linux system you will be finding your proxy settings in **Network settings**.

Since I use a Debian based distro I have it in Settings > Network > Proxy.

### Windows
Settings > Network and Internet > Proxy

## Final Notes
You can lookup how this proxy server can be used to connect to **multiple devices on the same network**. This was a tutorial for setting it up on one device.

If your router supports it, **configure your router** settings to use the proxy.