Greetings!

In this assignment, you will be writing an HTTP server by hand.

Your task is to create an application that acts as a sort of file-access server, using the HTTP protocol to perform the "create, retrieve, update, delete" (CRUD) operations.

To do this...

... you must have a copy of this repository in your GitHub account. You can do this one of two ways:

1. Fork this repository. From the GitHub repository web page, click "Fork" in the upper-right. This will create a copy of this repository in your own GitHub account. From there do a git clone from your own copy of the GitHub repository. (If you are unsure of the clone syntax, open the new repository in your account from the web, and click the green "Code" button--it will offer the correct syntax to use.)

2. Clone and re-home this repository. Open a "Command Prompt" or "Terminal" instance and use:

    git clone https://github.com/tedneward/INFO314-HTTPServer
   

   ... to do the deed. This will also create a local copy of the project on your machine in a directory called INFO314-HTTPServer. You will also need to "re-home" your local copy so it points to your own GitHub account; you can do this by creating a repository of this same name (INFO314-HTTPServer) in your GitHub account and then executing git remote set-url origin https://github.com/[your-ID]/INFO314-HTTPServer.git.

   In order to store your changes to your own GitHub account, you need to create a new repository on GitHub (call it INFO314-HTTPServer), and then change the project's settings to point to that new repository as the remote origin.

    git remote set-url origin https://github.com/[your-ID]/INFO314-HTTPServer.git
   

   Note, this will appear to succeed whether you got the syntax of the URL correct or not, so do a quick push to make sure it all worked correctly:

    git push
   

   Git will ask you for your username and password, then (if everything was done correctly), it will upload the code to the new repository, and this is your new "home" for this project going forward. Verify the files are there by viewing your GitHub project through the browser.

   (Needless to say, it's a lot easier to fork the repo!)

Now, you can begin to work on the homework code.

Stories/rubric

This assignment is worth 10 points, total. Your server must:

• Listen on port 8080. (If you use a different port, notify the TA before grading.)
• Respond to the GET request. (2 pts) Have your server respond as any HTTP server would: find the relative file given in the URL portion of the HTTP RequestLine and send the contents back as the body of an HTTP response. Make sure you have Content-Length and Content-Type set correctly!
• Respond to the PUT request. (2 pts) For this, have your server take the body sent along with the PUT request and write it to a new file given by the URL portion of the HTTP RequestLine. (In other words, PUT /test.txt HTTP/1.0 should write the body to a new file called "test.txt" in the same directory as this code.) Make sure you honor Content-Length crrectly in the incoming request.
• Respond to the POST request. (2 pts) This is similar to the PUT request, except that the body should be appended to the existing file (if any).
• Respond to the DELETE request. (2 pts) Have your server delete the file given in the URL portion of the HTTP RequestLine.
• Respond with HTTP error codes as appropriate. (2 pts) For example, for a GET or a DELETE request, if no such file is present, return a 404. Implement any other error codes that seem relevant, using your best judgement.

Extra credit

You can earn a few extra credit points on this assignment:

• Implement OPTIONS. (1 pt) For a given URL, determine what HTTP verbs would be supported here: if the file exists, then we can GET it, POST it, and DELETE it. If the file doesn't exist, we can PUT it or POST it.

• Implement HEAD. (1 pt) This is like a GET, except it will return only the ResponseLine and any headers in the response.

• Implement HttpCats. (1 pt) When sending back any error response (4xx or 5xx), send back HTML content as part of the body, using the HTTPCats image in the HTML body.

    <html><body><h1>501 - Not Implemented</h1><img src="https://http.cat/501"</img></body></html>
  

Testing

The curl utility is a popular command-line testing tool, and you can use it to drive your HTTP server like so:

• GET a particular resource: curl http://localhost:8080/test.txt
• PUT a particular resource: curl -X PUT --data-ascii "This is a test" http://localhost:8080/test.txt
• POST a particular resource: curl --data-ascii "This is a test" http://localhost:8080/text.txt
• DELETE a particular resource: curl -X DELETE http://localhost:8080/test.txt