Add small fixes to lab6 and lab11

Adressing issues from @padiazg also adding small changes
to the lab11 like changing name from `clearHash` to `getHash`
and adding `python` `yml` and `bash` to the code snippets

Signed-off-by: Martin Dekov (VMware) <[email protected]>

Author: martindekov

hmac-protected/hmac-protected/handler.py

@@ -3,15 +3,15 @@
 def validateHMAC(message, secret, hash):
 
     # GitHub and the sign flag prefix the hash with "sha1="
-    receivedHash = clearHash(hash)
+    receivedHash = getHash(hash)
 
     # Hash message with secret
     expectedMAC = hmac.new(secret.encode(), message.encode(), hashlib.sha1)
     createdHash = expectedMAC.hexdigest()
 
     return receivedHash == createdHash
 
-def clearHash(hash):
+def getHash(hash):
     if "sha1=" in hash:
         hash=hash[5:]
     return hash

lab11.md

@@ -4,11 +4,17 @@
 
 Before starting this lab create a new folder
 
-```
+```bash
 mkdir -p lab11 \
    && cd lab11
 ```
 
+also make sure your `faas-cli` version is `0.7.4` or above with the following command:
+
+```
+$ faas-cli version
+```
+
 ## What is HMAC
 
 Without any form of authentication or trust our functions may be exposed to anyone who can guess their URL. If our functions are accessible on the Internet or the local network then they could be invoked by a bad actor. By default functions respond to any request. However, if we want to control access to functions we can use Hash-based Message Authentication Code (HMAC) to validate the source of information.
@@ -26,7 +32,7 @@ We will use the `--sign` flag provided by faas-cli to send a header containing t
 
 Let's first inspect what the flag does by deploying the `env` function which will print all of the environmental variables accessible inside the function:
 
-```
+```bash
 $ faas-cli deploy --name env --fprocess="env" --image="functions/alpine:latest"
 ```
 
@@ -71,23 +77,23 @@ We see the `HMAC` being provided as the environmental variable `Http_Hmac`. The
 
 For our purpose we are going to create a new Python 3 function. Let’s call it `hmac-protected`:
 
-```
+```bash
 $ faas-cli new --lang python3 hmac-protected --prefix="<your-docker-username>"
 ```
 
 Add `payload-secret` which will serve as the key that will hash the payload. 
 
 Create `payload-secret` like we did in [lab10](https://github.com/openfaas/workshop/blob/master/lab10.md):
 
-```
+```bash
 $ echo -n "<your-secret>" | docker secret create payload-secret -
 ```
 
 > Note: Remember the string you put in place of  `<your-secret>`
 
 Our `hmac-protected.yml` should look like:
 
-```
+```yml
 provider:
   name: faas
   gateway: http://127.0.0.1:8080
@@ -103,23 +109,21 @@ functions:
 
 Replace the content of the `handler.py` with the following code:
 
-```
+```python
 import os, hmac, hashlib
 
 def validateHMAC(message, secret, hash):
 
     # GitHub and the sign flag prefix the hash with "sha1="
-    receivedHash = clearHash(hash)
-    encodedSecret = secret.encode()
-    encodedMessage = message.encode()
+    receivedHash = getHash(hash)
 
     # Hash message with secret
-    expectedMAC = hmac.new(encodedSecret,encodedMessage,hashlib.sha1)
+    expectedMAC = hmac.new(secret.encode(), message.encode(), hashlib.sha1)
     createdHash = expectedMAC.hexdigest()
 
     return receivedHash == createdHash
 
-def clearHash(hash):
+def getHash(hash):
     if "sha1=" in hash:
         hash=hash[5:]
     return hash
@@ -158,7 +162,7 @@ On receipt of the request, the function will use `payload-secret` to sign the re
 
 Here we compare the generated and received hashes:
 
-```
+```python
 ...
     if hmacDigest == cleanHash:
         return True
@@ -168,7 +172,7 @@ Here we compare the generated and received hashes:
 
 * Invoke the function with the flag:
 
-```
+```bash
 $ echo -n "This is a message" | faas-cli invoke hmac-protected --sign hmac --key=<your-secret>
 ```
 

lab6.md

@@ -125,6 +125,26 @@ Open your browser and access http://127.0.0.1:8080/function/show-html. You shoul
 
 Now we're going to add a path to the function URL.
 
+Inside `html` folder add new `list.html` file with this content:
+
+```html
+<!DOCTYPE html>
+<html lang='en'>
+<head>
+  <meta charset='UTF-8'>
+  <title>OpenFaaS</title>
+</head>
+<body>
+  <h2>This is a list!</h2>
+  <ul>
+    <li>One</li>
+    <li>Two</li>
+    <li>Three</li>
+  </ul>
+</body>
+</html>
+```
+
 Edit your `handler.py` to the following:
 
 ```python
@@ -174,7 +194,7 @@ Now that we've understood how to serve html via functions, let's dynamically cha
 
 The query string is `action=new`, hence the value of `Http_Query` would be `action=new`. We can also use the `parse_qs` function from the `urllib.parse` package and easily parse this query string.
 
-First of all, let's create a new HTML file inside called `list.html`. So the structure should look like the following now:
+The structure of the directory of our function looks like this:
 
 ```
 ├── show-html
@@ -187,25 +207,7 @@ First of all, let's create a new HTML file inside called `list.html`. So the str
 └── show-html.yml
 ```
 
-Edit `list.html`:
 
-```html
-<!DOCTYPE html>
-<html lang='en'>
-<head>
-  <meta charset='UTF-8'>
-  <title>OpenFaaS</title>
-</head>
-<body>
-  <h2>This is a list!</h2>
-  <ul>
-    <li>One</li>
-    <li>Two</li>
-    <li>Three</li>
-  </ul>
-</body>
-</html>
-```
 
 Change your `handler.py`: