## Simple CDN Design

I wanna create a simple cdn server to serve my static files.

Design the cdn server.

### Goals

- Upload files
- Service static
- Cheep to use

### Architecture

```mermaid
flowchart TD
  A[Jonathan]
  B[Frontend Cache Server]
  C[Reverse Proxy]
  D[Upload Server]
  Z[Storage Backend]
  A-->C
  C-->B
  B-->Z
  A-->C
  C-->D
  D-->Z
```

### Choose Solutions

#### 1. Reverse Proxy

Now using Caddy server.

Caddy can automate create https and setup proxy very easy.

TODO: Save Caddy certificates to s3.

#### 2. Frontend Cache Server

In my knowledgement base, varnish is the best software.

#### 3. Upload Server

I have to write it myself. So it easily fit my servers.

#### 4. Storage Backend

The AWS Simple Storage Service (s3) is the cheapest way as I known.