App Engine

Question 1

What are some of the handy built in features GAE provides?

Answer 1

• Turn-key support for many languages
• Built-in scaling system
• Easy deployment of apps via GIT

Question 2

What command do you need to run to create a new project on GAE?

Answer 2

gcloud app create –project=

Question 3

What command do you need to run to install Python on GAE?

Answer 3

gcloud components install app-engine-python

Question 4

What are the files needed to make an app on GAE?

Answer 4

• app.yaml
• requirements.txt
• main.py

Question 5

What is for app.yaml file for?

Answer 5

General configuration file for the application

Question 6

What is for requirements.txt file for?

Answer 6

Specifies modules/libraries to install in the environment

Question 7

What is for main.py file for?

Answer 7

The backend application code

Question 8

What command do you need to deploy your app on GAE?

Answer 8

gcloud app deploy

Question 9

What command do you need to open your app on a new browser?

Answer 9

gcloud app browse

Question 10

What happens to instances when your app is idle?

Answer 10

They get spun down

Question 11

What are the ways we can implement a DB as part of our app?

Answer 11

• Use a file-based DB (SQLite)
• Use Datastore
• Use Google Cloud Storage

Question 12

What are the cons of using a file-based DB such as SQLite

Answer 12

Not persistent

Every new instance starts back a 0

Question 13

Why might you use a file-based DB such as SQLite

Answer 13

If youre working with static non changing content

Question 14

What is Google Datastore?

Answer 14

A NoSQL Database

Deals with keys & values instead of tables & rows

Question 15

What are the steps to use google datastore?

Answer 15

1. Import it
   from google.cloud import datastore
2. Create new Client object
   datastore_client = datastore.Client()

3. Add module to requirements.txt
google-cloud-datastore==2.1.6

Question 16

How do you write to google datastore?

Answer 16

1. Create entity
   entity = datastore.Entity(key=myClient.key(‘hello’))
2. Update entity
   entity. update({‘myVal’: ‘world’})
3. Write the entity back to the datastore
   myClient.put(entity)

Question 17

How do you fetch from google datastore?

Answer 17

entity = myClient.get(‘hello’)

return entity[‘myVal’] # should return ‘world’

Question 18

What DB do you use to store files?

Answer 18

Google Cloud Storage

Question 19

How does Google Cloud Storage work?

Answer 19

You can a bucket for your app that can be used to store and serve files your your app

Question 20

What are the steps to use google cloud storage?

Answer 20

1. Import the module and create a client object
from google.cloud import storage
client = storage.Client()

2. Fetch bucket ID
   from google.appengine.api import app_identity
   import os
   buckid = os.environ.get(‘BUCKET_NAME’, app_identity.get_default_gcs_bucket_name())

Question 21

How do you fetch from google cloud storage?

Answer 21

1. Fetch bucket
   bucket = client.get_bucket(buckid)
2. Fetch blob of data
   blob = bucket.get_blob(‘/my/lovely/file.txt’)
3. fetch bytes from blob
   data = blob.download_as_bytes()

Question 22

What does the Client() function do?

Answer 22

Return a Client object that can be used to make subsequent calls to the Datastore

Question 23

What are the 3 ways to split traffic?

Answer 23

• IP address
• Cookie
• Random

Question 24

By default, where does google redirect traffic?

Answer 24

To the newest version of the app

Question 25

What are the types of environment variables?

Answer 25

- GAE_INSTANCE | - GAE_VERSION

Question 26

What does te getenv function do?

Answer 26

Fetches an environment variable

Question 27

What does os.getenv('GAE_INSTANCE') return?

Answer 27

The instance that we are communicating with

Question 28

What does os.getenv('GAE_VERSION') return?

Answer 28

The current version of the application that you are interfacing with

Question 29

What are the 2 different environments in GAE?

Answer 29

- Standard | - Flexible

Question 30

What are the cons of using a flexible environment?

Answer 30

- Can't scale down to 0 instances - Longer boot times - Pricing based on compute instance characteristics