CMU 15-112: Fundamentals of Programming and Computer Science
Class Notes: Serving and Deploying Websites

1. What is A Server
2. How to Serve Files
3. URL To Directory Mapping

1. What is A Server
   • A server is a program that listens for requests for data, processes those requests, and responds with data.
   • We will be working with file servers. These servers will receive requsets for html files and send them to your browser.


2. How to Serve Files
   
   • Running the following files or commands from a directory with html files in it will create a file server that is able to serve files from that directory.
   
   
   • This is a simple file server written in Python.
     import http.server import socketserver PORT = 3000 handler = http.server.SimpleHTTPRequestHandler with socketserver.TCPServer(("", PORT), handler) as httpd: print("serving at port", PORT) httpd.serve_forever()
   • 
     This is a simple file server written in Go.
     package main import ( "fmt" "net/http" ) func main() { PORT := "3000" http.Handle("/", http.FileServer(http.Dir("."))) fmt.Println("serving at port", PORT) http.ListenAndServe(":"+PORT, nil) }
   
   
   • And this is a line you can run in your Terminal to start a server:
     python3 -m http.server 3000


3. URL To Directory Mapping
   Say we run python3 -m http.server 3000 from a directory with the following file structure:
   
   |-index.html |-page2.html |-dir1 |---index.html |---page3.html
   Visiting http://localhost:3000/ will bring us to "index.html". When there is no html file specified after a path, the server automatically looks for "index.html".
   Visiting http://localhost:3000/page2.html will bring us to "page2.html"
   Visiting http://localhost:3000/dir1 will bring us to "dir1/index.html"
   Finally, visiting http://localhost:3000/dir1/page3.html will bring us to "dir1/page3.html"
   
   We can create relative links between pages. For example, the tag <a href="page2.html">link</a> in "index.html" would link to page2.html.