This project is Amazon DynamoDB training and demo app.

Realtime Comment Demo App

High level architecture

Environment

DynamoDB (using GSI)

Python 3.7.3+

Please read Chalice project doc. https://github.com/aws/chalice

local test needs DynamoDB Local. https://docs.aws.amazon.com/ja_jp/amazondynamodb/latest/developerguide/DynamoDBLocal.html

If you set API_ENDPOINT environment value 'localhost' is using DynamoDB Local (ex: export API_ENDPOINT=localhost)

Amazon DynamoDB setting

DynamoDB Local

 aws dynamodb create-table \
     --endpoint-url http://localhost:8000\
     --table-name chat \
     --attribute-definitions AttributeName=name,AttributeType=S AttributeName=time,AttributeType=S AttributeName=chat_room,AttributeType=S\
     --key-schema KeyType=HASH,AttributeName=name KeyType=RANGE,AttributeName=time\
     --global-secondary-indexes 'IndexName=chat_room_time_idx,KeySchema=[{AttributeName=chat_room,KeyType=HASH},{AttributeName=time,KeyType=RANGE}],ProvisionedThroughput={ReadCapacityUnits=1,WriteCapacityUnits=1},Projection={ProjectionType=ALL}' \
     --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

DynamoDB

 aws dynamodb create-table \
     --table-name chat \
     --attribute-definitions AttributeName=name,AttributeType=S AttributeName=time,AttributeType=S AttributeName=chat_room,AttributeType=S\
     --key-schema KeyType=HASH,AttributeName=name KeyType=RANGE,AttributeName=time\
     --global-secondary-indexes 'IndexName=chat_room_time_idx,KeySchema=[{AttributeName=chat_room,KeyType=HASH},{AttributeName=time,KeyType=RANGE}],ProvisionedThroughput={ReadCapacityUnits=1,WriteCapacityUnits=1},Projection={ProjectionType=ALL}' \
     --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1

Deploy

This operation needs IAM permission for chalice deploy and using dynamodb.Please check chalice document.

https://github.com/aws/chalice#credentials

local app start

If you set API_ENDPOINT environment value 'localhost' is using DynamoDB Local 
 (ex: export API_ENDPOINT=localhost)

 # example : DynamoDB local setup command
 java -Djava.library.path=./DynamoDBLocal_lib -jar DynamoDBLocal.jar -port 8000 -inMemory

 # chalice local start up
 chalice local --stage local --port 8080

Please create DDB local or local DDB test envroiment.

Production Deploy

1st step : 1st chalice deploy

chalice deploy

2nd step : Check your generate APIGateway URL

If your 1st chalice deploy done, cli console log is like here.

INFO:Found credentials in shared credentials file: ~/.aws/credentials
Updating policy for IAM role: dynamodb-python-chat-sample-dev-api_handler
Updating lambda function: dynamodb-python-chat-sample-dev
Updating rest API
Resources deployed:
  - Lambda ARN: arn:aws:lambda:ap-northeast-1:YOUR_AWS_ACCOUNT_ID:function:dynamodb-python-chat-sample-dev
  - Rest API URL: https://your_APIGW_ENDPONT.execute-api.ap-northeast-1.amazonaws.com/api/ 

3rd step : set to your api endpoint URL

.chalice/config.json 
----------

      "dev": {
        "environment_variables": {
                "API_ENDPOINT": "https://your_API_ENDPOINT"
            }
        }

->

      "dev": {
        "environment_variables": {
                "API_ENDPOINT": "https://your_APIGW_ENDPONT.execute-api.ap-northeast-1.amazonaws.com/api/"
            }
        }

4th step : 2nd chalice deploy

chalice deploy

Python Test

pytest should be run without a chat table. If there is an existing table, the test will fail.

Project root dir "pytest -vv"

Amazon DynamoDB Data Modeling

Amazon DynamoDB Data Modeling:

name(PK)	time(SK)	comment	chat_room
string	string(micro sec unixtime)	string	string

GSI

chat_room(PK)	time(SK)	comment	name
string	string(micro sec unixtime)	string	string

NoSQL Workbench for DynamoDB capture

this test data json is amazon_dynamodb_chat_sample.json

API

• /chat

return chat client HTML and js.

• /chat/comments/add

client sent post request with name,comment txt, get response add comment status

POST value {"name": "oranie", "comment":"hello world"}

• /chat/comments/all

client sent get request, get all comment.

• /chat/comments/latest

client sent get request latest 20 comments.

• /chat/comments/latest/{latest_seq_id}

client sent get request with latest chat id, get the difference comments.

License

This library is licensed under the MIT-0 License. See the LICENSE file.