This project is training and demo app using Cassandra.

Realtime Comment Demo App

High level architecture

Envroiment

golang 1.13

Docker version 19.03.5, build 633a0ea

Environment Setting

If you need to run app on CI/CD,test and prpduction environment.Please overwrite these value.

EnvironmentName	Description	Default value
CASSANDRA_ENDPOINT	Cassandra cluster endpoint(ip or domain)	127.0.0.1
CASSANDRA_USER	Cassandra cluster user	cassandra
CASSANDRA_PASS	Cassandra cluster user pass	cassandra
CASSANDRA_PORT	Cassandra cluster network port	9042
CASSANDRA_KS	Cassandra cluster key spacename	example
APP_ENDPOINT	Chat App use Endpoint	http://127.0.0.1
APP_PORT	Chat App use network port	8080
APP_ENV	App run envroiment	test
Build setting
IMAGE_REPO_NAME	Docker container repogitory name.
IMAGE_TAG	Docker container tag
AWS_DEFAULT_REGION	Docker container repogitory region
AWS_ACCOUNT_ID	for Docker container repogitory

Local app start

go run ./main.go

note: If you need to connect remote cassandra cluster, It might be a good idea to use an SSH tunnel.

ssh ${SSH_TUNNEL_HOST} -L 9042:${CASSANDRA.ENDPOINT}:9042

Build and Deploy

This project build docker container.Any environment where containers and Cassandra can run is OK. Example using ECR, ECS Fargate, Amazon MCS.

Cassandra setting(Amazon MCS)

https://docs.aws.amazon.com/mcs/latest/devguide/accessing.html

https://docs.aws.amazon.com/mcs/latest/devguide/getting-started.html

Create Cassandra connect user

aws iam create-service-specific-credential --user-name USERNAME --service-name cassandra.amazonaws.com

cqlsh ssl setting

curl https://www.amazontrust.com/repository/AmazonRootCA1.pem -O

cat $HOME/.cassandra/cqlshrc

[connection]
port = 9142
factory = cqlshlib.ssl.ssl_transport_factory

[ssl]
validate = true
certfile =  $HOME/AmazonRootCA1.pem

connect Amazon MCS
cqlsh {endpoint} {port} -u {ServiceUserName} -p {ServicePassword} --ssl

Create KeySpace(This app auto create table.)

CREATE KEYSPACE IF NOT EXISTS example WITH REPLICATION={'class': 'SingleRegionStrategy'};

If you want run Cassandra node on EC2, This project ./cassandra_conf_sample/cassandra.yaml may be helpful, Using Docker containers is also effective

https://hub.docker.com/_/cassandra

Create ECR repository

https://docs.aws.amazon.com/ja_jp/AmazonECR/latest/userguide/ECR_AWSCLI.html

Build and push container image(example Amazon ECR)

GOOS=linux GOARCH=amd64 CGO_ENABLED=0  go build ./main.go
docker build -t $IMAGE_REPO_NAME .
docker tag $IMAGE_REPO_NAME:$IMAGE_TAG $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG
docker push $AWS_ACCOUNT_ID.dkr.ecr.$AWS_DEFAULT_REGION.amazonaws.com/$IMAGE_REPO_NAME:$IMAGE_TAG

This operation is written in buildspec.yaml for codebuild.

CodeBuild

https://docs.aws.amazon.com/ja_jp/codebuild/latest/userguide/sample-docker.html

Create ECS Fargate Cluster

https://docs.aws.amazon.com/ja_jp/AmazonECS/latest/developerguide/ECS_GetStarted_Fargate.html

Create ECS task difinition

Create ECS Service

If you run 1 container task, not need ALB or NLB.

Data Modeling

Data Modeling:

Pattern 1

name(PK)	time(clustering column)	comment	chat_room
text	text(micro sec unixtime)	text	text

Pattern 2

chat_room(PK)	time(clustering column)	comment	name
text	text(micro sec unixtime)	text	text

API List

Return server status.

/run-test

return test data insert and select result.

/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.

oranie/cassandra-sample-golang