Twittard

Sample Microservice Cloud Application

List of Service

• config-service
• discovery-service
• gateway-service
• comment-service
• tweet-service

How to run?

Because the services depend on remote config, config-service must run first than the other services.

1. Build the application

   mvn clean install

2. Run service, assumed we are in root directory of project /twittard.

   config-service

   java -jar config-service/target/config-service-0.0.1-SNAPSHOT.jar

   discover-service

   java -jar discovery-service/target/discovery-service-0.0.1-SNAPSHOT.jar

   comment-service

   java -jar comment-service/target/comment-service-0.0.1-SNAPSHOT.jar

   tweet-service

   java -jar tweet-service/target/tweet-service-0.0.1-SNAPSHOT.jar

   gateway-service

   java -jar gateway-service/target/gateway-service-0.0.1-SNAPSHOT.jar

Project stack/feature detail

• SPRING BOOT v2.5.14

  In this version each library seems more stable and not much bug/break changes to each other libs.

• SPRING CLOUD v2020.0.5

  To match spring boot version

• JAVA jdk17

  Because the project itself is for demo purposed, then I use the newest LTS version of JDK.

For sake of simplicity services developed in maven multi module and stored in git monorepo 

Module/Feature	INCLUDE	DETAIL
Spring Cloud Config	YES	to centralized config of service/application
Spring Cloud Eureka	YES	Service discovery/registry
Spring Cloud Gateway	YES	gateway
Spring Cloud OpenFeign	YES	http client
Spring Data REST	YES	to simplify/auto generate CRUD
Swagger	YES	auto generate api documentation
Spring Security OAuth	NO	security
Unit Testing	NO	automate testing

Swagger endpoints

COMMENT-SERVICE swagger

• http://localhost:9090/v2/api-docs
• http://localhost:9090/swagger-ui/

TWEET-SERVICE swagger

• http://localhost:8080/v2/api-docs
• http://localhost:8080/swagger-ui/

USER-SERVICE swagger

• http://localhost:7070/v2/api-docs
• http://localhost:7070/swagger-ui/

Demo http request (Gateway)

NOTE:
For the sake of simplicity, then
1. In comment-service the database used is H2 in memory database, so the data will not persisted to disk, or the data will be lost if the application terminated.
2. In tweet-service the data is not store to any of database, the data is in memory in code(hard-coded), so the data will remain same, everytime the application is run.

1. Create Comment

Request

curl --location --request POST 'localhost/comments' \
--header 'Content-Type: application/json' \
--data-raw '{
   "tweetId": 1,
   "userId": 1,
   "content": "Monrning!"
}'

Response

{
    "id": 1,
    "userId": 1,
    "tweetId": 1,
    "content": "Monrning!",
    "_links": {
        "self": {
            "href": "http://192.168.245.112:9090/comments/1"
        },
        "comment": {
            "href": "http://192.168.245.112:9090/comments/1"
        }
    }
}

2. Get Comments

Request

curl --location --request GET 'localhost/comments'

Response

{
    "_embedded": {
        "comments": [
            {
                "userId": 1,
                "tweetId": 1,
                "content": "Morning!",
                "_links": {
                    "self": {
                        "href": "http://192.168.245.112:9090/comments/1"
                    },
                    "comment": {
                        "href": "http://192.168.245.112:9090/comments/1"
                    }
                }
            }
        ]
    },
    "_links": {
        "self": {
            "href": "http://192.168.245.112:9090/comments"
        },
        "profile": {
            "href": "http://192.168.245.112:9090/profile/comments"
        }
    },
    "page": {
        "size": 20,
        "totalElements": 1,
        "totalPages": 1,
        "number": 0
    }
}

3. Get Tweet

Request

curl --location --request GET 'localhost/tweets/1'

Response

{
    "id": 1,
    "userId": 1,
    "content": "Hello, Good Morning!",
    "comments": [
        {
            "id": 1,
            "userId": 1,
            "tweetId": 1,
            "content": "Monrning!"
        }
    ]
}

4. Get Tweets

Request

curl --location --request GET 'localhost/tweets?userId=1'

Response

[
    {
        "id": 1,
        "userId": 1,
        "content": "Hello, Good Morning!"
    },
    {
        "id": 2,
        "userId": 1,
        "content": "Hello, Good Afternoon!"
    },
    {
        "id": 3,
        "userId": 1,
        "content": "Hello, Good Evening!"
    }
]