Create an HTTP Google Cloud Function

Learning Objectives

Successfully complete this lab by achieving the following learning objectives:

Enable APIs and Set Up the Cloud Shell

To help us create our first Cloud Function, we will enable some APIs and get ready to use the Cloud Shell editor and terminal.

1. Inside the GCP console, click the Activate Cloud Shell icon.
2. Click the down triangle next to the project ID at the top of the page.
3. When the dialog opens, copy the current Project ID.
4. In the Cloud Shell, enter the following command:
   

   gcloud config set project <PROJECT_ID>

5. Then, run this command to enable the necessary APIs:
   

   gcloud services enable cloudbuild.googleapis.com cloudfunctions.googleapis.com

6. Create a directory for your function and move into that directory.
7. In the Cloud Shell, click Open Editor. Then choose Open in a new window.
8. When the editor has opened in a new tab, go back to your original tab and click Open Terminal to get the terminal back.

You are now ready to start building your first Cloud Function.

Write the Hello World Function

1. In the helloworld directory, create the main.py file using the Cloud Shell editor:

   from flask import escape
   def hello_http(request):
       request_json = request.get_json(silent=True)
       request_args = request.args
       if request_json and 'name' in request_json:
           name = request_json['name']
       elif request_args and 'name' in request_args:
           name = request_args['name']
       else:
           name = 'World'
       return 'Hello {}!'.format(escape(name))

2. Also inside the helloworld directory, create the requirements.txt file, specifying the Flask library and the version of the library.

Deploy and Test the Hello World Function

1. Back in the Cloud Shell terminal, and inside the helloworld directory, deploy the Hello World function.
2. From the GCP menu, select Cloud Functions from the Compute section. Then select the hello_http function. Observe the various tabs that show you the details of your deployed function.
3. Under the Trigger tab, click the URL and follow the redirect to trigger your function and see the "Hello World!" response.
4. To customize the response, add a query parameter to the end of the URL (for example, ?name=Cloud%20Gurus).