Add part 1 of Lab 6, rename space-counter function

Signed-off-by: Alex Ellis (VMware) <alexellis2@gmail.com>

README.md

@@ -35,7 +35,7 @@ Disclaimer: this workshop is a work-in-progress - labs 2-5 are ready.
 ## [Lab 3 - Introduction to Functions](./lab3.md)
 
 * Scaffold or generate a new function
-* Build the space-counter function
+* Build the astronaut-finder function
  * Add dependencies with `pip`
 * Troubleshooting: verbose output with `write_debug`
 * Troubleshooting: find the container's logs

space-counter.yml → astronaut-finder.yml

@@ -3,7 +3,7 @@ provider:
   gateway: http://localhost:8080
 
 functions:
-  space-counter:
+  astronaut-finder:
     lang: python
-    handler: ./space-counter
-    image: space-counter
+    handler: ./astronaut-finder
+    image: astronaut-finder

space-counter/handler.py → astronaut-finder/handler.py

@@ -1,10 +1,11 @@
 import requests
 import random
 
-def handle(st):
+def handle(req):
     r = requests.get("http://api.open-notify.org/astros.json")
     result = r.json()
+
     index = random.randint(0, len(result["people"])-1)
     name = result["people"][index]["name"]
 
-    print (name + " is in space")
+    print("%s is in space" % name)

lab3.md

@@ -116,35 +116,35 @@ Functions can be invoked via a `GET` or `POST` method only.
 
 Test out the function with `faas-cli invoke`, check `faas-cli invoke --help` for more options.
 
-### Example function: space-counter
+### Example function: astronaut-finder
 
-We'll create a function that pulls in a random name of someone in space aboard the International Space Station (ISS).
+We'll create a function called `astronaut-finder` that pulls in a random name of someone in space aboard the International Space Station (ISS).
 
 ```
-$ faas new --lang python space-counter
+$ faas new --lang python astronaut-finder
 ```
 
 This will write three files for us:
 
 ```
-./space-counter/handler.py
+./astronaut-finder/handler.py
 ```
 
 The handler for the function - you get a `req` object with the raw request and can print the result of the function to the console.
 
 ```
-./space-counter/requirements.txt
+./astronaut-finder/requirements.txt
 ```
 
 This file lists any `pip` modules you want to install, such as `requests` or `urllib`
 
 ```
-./space-counter.yml
+./astronaut-finder.yml
 ```
 
 This file is used to manage the function - it has the name of the function, the Docker image and any other customisations needed.
 
-* Edit `./space-counter/requirements.txt`
+* Edit `./astronaut-finder/requirements.txt`
 
 ```
 requests
@@ -182,24 +182,24 @@ def handle(req):
 Now build the function:
 
 ```
-$ faas build -f ./space-counter.yml
+$ faas build -f ./astronaut-finder.yml
 ```
 
-> Tip: If you rename space-counter.yml to `stack.yml` then you can leave off the `-f` argument. `stack.yml` is the default file-name for the CLI.
+> Tip: If you rename astronaut-finder.yml to `stack.yml` then you can leave off the `-f` argument. `stack.yml` is the default file-name for the CLI.
 
 Deploy the function:
 
 ```
-$ faas deploy -f ./space-counter.yml
+$ faas deploy -f ./astronaut-finder.yml
 ```
 
 Invoke the function
 
 ```
-$ echo | faas invoke space-counter
+$ echo | faas invoke astronaut-finder
 Anton Shkaplerov is in space
 
-$ echo | faas invoke space-counter
+$ echo | faas invoke astronaut-finder
 Joe Acaba is in space
 ```
 
@@ -208,9 +208,9 @@ Joe Acaba is in space
 You can find out high-level information on every invocation of your function via the container's logs:
 
 ```
-$ docker service logs -f space-counter
-space-counter.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:25 Forking fprocess.
-space-counter.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Wrote 18 Bytes - Duration: 0.063269 seconds
+$ docker service logs -f astronaut-finder
+astronaut-finder.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:25 Forking fprocess.
+astronaut-finder.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Wrote 18 Bytes - Duration: 0.063269 seconds
 ```
 
 ## Troubleshooting: verbose output with `write_debug`
@@ -225,34 +225,34 @@ provider:
   gateway: http://localhost:8080
 
 functions:
-  space-counter:
+  astronaut-finder:
     lang: python
-    handler: ./space-counter
-    image: space-counter
+    handler: ./astronaut-finder
+    image: astronaut-finder
 ```
 
 Edit your YAML file for the function and add an "environment" section.
 
 ```
-  space-counter:
+  astronaut-finder:
     lang: python
-    handler: ./space-counter
-    image: space-counter
+    handler: ./astronaut-finder
+    image: astronaut-finder
     environment:
       write_debug: true
 ```
 
-Now deploy your function again with `faas-cli deploy -f ./space-counter.yml`.
+Now deploy your function again with `faas-cli deploy -f ./astronaut-finder.yml`.
 
 Invoke the function and then checkout the logs again to view the function responses:
 
 ```
-$ docker service logs -f space-counter
-space-counter.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:25 Forking fprocess.
-space-counter.1.szobw9pt3m60@nuc    | 2018/02/26 14:49:57 Query  
-space-counter.1.szobw9pt3m60@nuc    | 2018/02/26 14:49:57 Path  /function/hello-openfaas
-space-counter.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Hello World
-space-counter.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Duration: 0.063269 seconds
+$ docker service logs -f astronaut-finder
+astronaut-finder.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:25 Forking fprocess.
+astronaut-finder.1.szobw9pt3m60@nuc    | 2018/02/26 14:49:57 Query  
+astronaut-finder.1.szobw9pt3m60@nuc    | 2018/02/26 14:49:57 Path  /function/hello-openfaas
+astronaut-finder.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Hello World
+astronaut-finder.1.1e1ujtsijf6b@nuc    | 2018/02/21 14:53:26 Duration: 0.063269 seconds
 ```
 
 ### Make use of custom templates

lab6.md

@@ -1,6 +1,44 @@
 # Lab 6 - Chain or combine Functions into workflows
 
-* Make use of another function
-* Director pattern
+## Call one function from another
+
+The easiest way to call one function from another is make a call over HTTP back to the API Gateway in OpenFaaS. This call does not need to know the external domain name or IP address, it can simply refer to the API Gateway as `gateway`.
+
+Example:
+
+In Lab 3 we introduced the requests module and used it to call a remote API to get the name of an astronaut aboard the ISS. We can use the same technique to call another function deployed on OpenFaaS.
+
+* Go to the *Function Store* and deploy the *Sentiment Analysis* function. 
+
+The Sentiment Analysis function will take any string and give whether it's subjective and positive or negative in a JSON response. The key field we want is `polarity`.
+
+```
+echo -n "California is great, it's always sunny there." | faas invoke sentimentanalysis
+{"polarity": 0.8, "sentence_count": 1, "subjectivity": 0.75}
+```
+
+So the result shows us that our test sentence was both very subjective (75%) and very positive (80%).
+
+The following code can be used to call the *Sentiment Analysis* function or any other function:
+
+```
+    test_sentence = "California is great, it's always sunny there."
+    r = requests.get("http://gateway:8080/function/sentimentanalysis", text= test_sentence)
+```
+
+Since the result is always in JSON format we can make use of the helper function `.json()` to convert the response:
+
+```
+    result = r.json()
+    if result["polarity" > 0.45]:
+        print("That was probably positive")
+    else:
+        print("That was neutral or negative")
+```
+
+Try generating a new function in Python putting it all together, remember to add `requests` to your `requirements.txt` file.
+
+## The Director pattern
+
 
 Now move onto [Lab 7](lab7.md)