springboot-graphql-databases

The goal of this project is to explore GraphQL. For it, we will implement two Spring Boot Web Java applications: author-book-api and book-review-api.

Note: In kubernetes-minikube-environment repository, it's shown how to deploy this project in Kubernetes (Minikube).

Proof-of-Concepts & Articles

On ivangfr.github.io, I have compiled my Proof-of-Concepts (PoCs) and articles. You can easily search for the technology you are interested in by using the filter. Who knows, perhaps I have already implemented a PoC or written an article about what you are looking for.

Additional Readings

[Medium] Implementing and Securing a Spring Boot GraphQL API with Keycloak
[Medium] Implementing and Securing a Spring Boot GraphQL API with Okta

Project Diagram

Applications

author-book-api

Spring Boot Web Java application that handles authors and books. It exposes a GraphQL endpoint and traditional REST API endpoints. author-book-api uses MySQL as storage and calls book-review-api to get the reviews of the books. It uses Feign to easily create a client for book-review-api and Resilience4j (fault tolerance library) to handle fallback when book-review-api is down. The book ISBN is what connects books stored in author-book-api with the ones stored in book-review-api.
book-review-api

Spring Boot Web Java application that handles books and their reviews. It only exposes a GraphQL API and uses MongoDB as storage.

Frontend applications

In the repository react-graphql-databases, I have implemented two ReactJS applications author-book-ui and book-review-ui that are frontend applications for author-book-api and book-review-api, respectively.

If you want to see the complete communication frontend-backend using GraphQL, clone the react-graphql-databases and follow the README instructions.

Prerequisites

Start Environment

Open a terminal and inside springboot-graphql-databases root folder run:
```
docker compose up -d
```
Wait for Docker containers to be up and running. To check it, run:
```
docker compose ps
```

Run applications with Maven

Inside springboot-graphql-databases, run the following Maven commands in different terminals:

author-book-api

./mvnw clean spring-boot:run --projects author-book-api \
-Dspring-boot.run.jvmArguments="-Dspring.datasource.username=authorbookuser -Dspring.datasource.password=authorbookpass"

book-review-api

./mvnw clean spring-boot:run --projects book-review-api \
-Dspring-boot.run.jvmArguments="-Dspring.data.mongodb.username=bookreviewuser -Dspring.data.mongodb.password=bookreviewpass"

Run Applications as Docker containers

Build Application's Docker Images

In a terminal and inside springboot-graphql-databases root folder, run the following script:

./docker-build.sh

Application's environment variables

author-book-api

Environment Variable	Description
`MYSQL_HOST`	Specify host of the `MySQL` database to use (default `localhost`)
`MYSQL_PORT`	Specify port of the `MySQL` database to use (default `3306`)
`ZIPKIN_HOST`	Specify host of the `Zipkin` distributed tracing system to use (default `localhost`)
`ZIPKIN_PORT`	Specify port of the `Zipkin` distributed tracing system to use (default `9411`)
`BOOK_REVIEW_API_HOST`	Specify host of the `book-review-api` service (default `localhost`)
`BOOK_REVIEW_API_PORT`	Specify port of the `book-review-api` service (default `9080`)

book-review-api

Environment Variable	Description
`MONGODB_HOST`	Specify host of the `MongoDB` database to use (default `localhost`)
`MONGODB_PORT`	Specify port of the `MongoDB` database to use (default `27017`)
`ZIPKIN_HOST`	Specify host of the `Zipkin` distributed tracing system to use (default `localhost`)
`ZIPKIN_PORT`	Specify port of the `Zipkin` distributed tracing system to use (default `9411`)

Start Applications as Docker containers

In a terminal and inside springboot-graphql-databases root folder, run following script:

./start-apps.sh

Application's Link

Application	URL Type	URL
author-book-api	Swagger	http://localhost:8080/swagger-ui.html
author-book-api	GraphiQL	http://localhost:8080/graphiql
book-review-api	GraphiQL	http://localhost:9080/graphiql

How to use GraphiQL

book-review-api

In a browser, access http://localhost:9080/graphiql;

Create a book and return its id:

mutation {
  createBook(bookInput: {title: "Getting Started With Roo", isbn: "9781449307905"}) {
   id
  }
}

Add one review for the book created above, suppose the id is 5bd4bd4790e9f641b7388f23:

mutation {
  addBookReview(bookId: "5bd4bd4790e9f641b7388f23", reviewInput: {reviewer: "Ivan Franchin", comment: "It is a very good book", rating: 5}) {
    id
  }
}

Get all books stored in book-review-api, including their reviews:

{
  getBooks {
    id
    title
    isbn
    reviews {
      comment
      rating
      reviewer
      createdAt
    }
  }
}

author-book-api
1. In a browser, access http://localhost:8080/graphiql;
2. Create an author and return the author id:
```
mutation {
  createAuthor(authorInput: {name: "Josh Long"}) {
    id
  }
}
```
3. Create a book and return the book id and author name:
  
  Note: while creating this book in author-book-api, we are setting the same ISBN, 9781449307905, as we did when creating the book in book-review-api.
```
mutation {
  createBook(bookInput: {authorId: 1, isbn: "9781449307905", title: "Getting Started With Roo", year: 2020}) {
    id
    author {
      name
    }
  }
}
```
4. Get author by id and return some information about his/her books including book reviews from book-review-api:
  
  Note: as the book stored in author-book-api and book-review-api has the same ISBN, 9781449307905, it's possible to retrieve the reviews of the book. Otherwise, an empty list will be returned in case book-review-api does not have a specific ISBN or the service is down.
```
{
  getAuthorById(authorId: 1) {
    name
    books {
      isbn
      title
      bookReview {
        reviews {
          reviewer
          rating
          comment
          createdAt
        }
      }
    }
  }
}
```
5. Update book title and return its id and new title:
```
mutation {
  updateBook(bookId: 1, bookInput: {title: "Getting Started With Roo 2"}) {
    id
    title
  }
}
```
6. Delete the author and return author id:
```
mutation {
  deleteAuthor(authorId: 1) {
    id
  }
}
```

Useful links & commands

Zipkin

It can be accessed at http://localhost:9411.

MySQL monitor

docker exec -it -e MYSQL_PWD=authorbookpass mysql mysql -uauthorbookuser --database authorbookdb
SHOW tables;
SELECT * FROM authors;
SELECT * FROM books;

Type exit to get out of MySQL monitor

MongoDB shell

docker exec -it mongodb mongosh -u bookreviewuser -p bookreviewpass --authenticationDatabase bookreviewdb
use bookreviewdb;
db.books.find().pretty();

Type exit to get out of MongoDB shell

Shutdown

To stop applications:
- If they were started with Maven, go to the terminals where they are running and press Ctrl+C;
- If they were started as a Docker container, go to a terminal and, inside springboot-graphql-databases root folder, run the script below:
```
./stop-apps.sh
```
To stop and remove docker compose containers, network and volumes, go to a terminal and, inside springboot-graphql-databases root folder, run the following command:
```
docker compose down -v
```

Cleanup

To remove the Docker images created by this project, go to a terminal and, inside springboot-graphql-databases root folder, run the following script:

./remove-docker-images.sh

TODO

implement test cases;
use HttpGraphQlClient to call book-review instead of feign (we need to convert to project to WebFlux);
study how to implement authentication/authorization to GraphQL endpoint;
implement graphql subscription;

ivangfr / springboot-graphql-databases Goto Github PK