demo-quarkus-webapp-postgres-k8s

‏ ‏ ‎ ‏ ‏ ‎

1. Create Backend-App and add Dependencies

create app on quarkus.io

Figure 1. create quarkus app with web gui

mit maven

mvn io.quarkus.platform:quarkus-maven-plugin:2.16.3.Final:create \
    -DprojectGroupId=at.htl.leonding.demo \
    -DprojectArtifactId=demo \
    -Dextensions='quarkus-resteasy-jackson,websockets,hibernate-orm-panache,jdbc-postgresql,jib'
cd demo

Troubleshooting

when there is a problem with 3.9.0 use an older one
- https://stackoverflow.com/a/75549674/9818338

mit maven

/opt/apache-maven-3.8.7/bin/mvn io.quarkus.platform:quarkus-maven-plugin:2.16.3.Final:create \
    -DprojectGroupId=at.htl.leonding.demo \
    -DprojectArtifactId=demo \
    -Dextensions='quarkus-resteasy-jackson,websockets,hibernate-orm-panache,jdbc-postgresql,jib'
cd demo

mit der Quarkus CLI

quarkus create app at.htl.leonding.demo:backend

quarkus ext add quarkus-resteasy-jackson websockets hibernate-orm-panache jdbc-postgresql jib

add assertj to pom.xml and click "Load maven changes"

<!-- https://mvnrepository.com/artifact/org.assertj/assertj-core -->
<dependency>
    <groupId>org.assertj</groupId>
    <artifactId>assertj-core</artifactId>
    <version>3.24.2</version>
    <scope>test</scope>
</dependency>
<!-- https://mvnrepository.com/artifact/org.assertj/assertj-db -->
<dependency>
    <groupId>org.assertj</groupId>
    <artifactId>assertj-db</artifactId>
    <version>2.0.2</version>
    <scope>test</scope>
</dependency>

2. Configure application.properties

src/main/resources/application.properties

quarkus.datasource.devservices.enabled=false
quarkus.http.root-path=/api

quarkus.datasource.db-kind=postgresql
quarkus.datasource.username=app
quarkus.datasource.password=app
quarkus.datasource.jdbc.url=jdbc:postgresql://localhost:5432/db

quarkus.hibernate-orm.database.generation=drop-and-create
quarkus.hibernate-orm.database.generation.halt-on-error=false
quarkus.hibernate-orm.sql-load-script=db/import.sql

quarkus.hibernate-orm.log.sql=true
quarkus.http.access-log.enabled=true

3. Local Postgres Database

3.1. Install Local Database

Download script for starting postgres in doxcker-compose
- http://edufs.edu.htl-leonding.ac.at/~t.stuetz/download/nvs/scripts/postgres/postgres-download-scripts.sh
copy postgres-download-scripts.sh into project-root
in terminal: chmod + ./postgres-download-scripts.sh

run in terminal:

./postgres-download-scripts.sh
./postgres-create-db.sh
./postgres-start.sh

output

[+] Running 2/2
 ⠿ Container pgadmin   Started                                                           0.5s
 ⠿ Container postgres  Started                                                           0.5s

3.2. Load Initial Data at Startup

create an import.sql-file

src/main/resources/db/import.sql

INSERT INTO public.tb_user (name) VALUES('Max Mustermann');
INSERT INTO public.tb_user (name) VALUES('Joe Sixpack');
INSERT INTO public.tb_user (name) VALUES('Jane Roe');
INSERT INTO public.tb_user (name) VALUES('John Doe');

3.3. Start Database Local

Terminal

./postgres-start.sh

output

[+] Running 3/3
 ⠿ Network db-postgres_postgres  Created                               0.0s
 ⠿ Container pgadmin             Started                               0.3s
 ⠿ Container postgres            Started                               0.3s

3.4. Stop Database Local

Terminal

./postgres-stop.sh

output

[+] Running 3/3
 ⠿ Container pgadmin             Removed                                                                       0.8s
 ⠿ Container postgres            Removed                                                                       0.1s
 ⠿ Network db-postgres_postgres  Removed                                                                       0.0s

3.5. Create Datasource for local database

When we downloaded and executed the postgres-download-scripts.sh we got a file datasource.txt
We open this file
Copy the whole content cmd+c / ctrl+c
and insert into

Details

4. First REST-request

Endpoint

package at.htl.leonding.demo;

import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType; (1)

@Path("/hello")
public class GreetingResource {

    @GET
    @Produces(MediaType.TEXT_PLAIN)
    public String hello() {
        return "Hello RESTEasy";
    }
}

1	Achtung auf den korrekten Import

./mvnw clean quarkus:dev

Figure 2. folder structure

Figure 3. run request

5. Erstellen der User-Funktionalität

Wir werden nun folgende Struktur erstellen:

Dabei werden die Klassen nicht entsprechend ihres Layers, sondern entsprechend der features gegliedert
Package by Layer vs Package by Feature

5.1. User

package at.htl.leonding.demo.entity.user;

public class User {

    Long id;
    String name;

}

cursor auf Feldnamen setzen
encapsulate fields Strg + T

Generieren der Constructors
- Alt + Einf / ⌘ + N

package at.htl.leonding.demo.entity.user;

public class User {

    private Long id;
    private String name;

    //region Constructors
    public User() {
    }

    public User(String name) {
        this.name = name;
    }
    //endregion

    //region getter and setter
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    //endregion
}

add jpa-annotations

package at.htl.leonding.demo.entity.user;

import javax.persistence.*;

@Entity
@Table(name = "TB_USER")
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;
    private String name;

    //region Constructors
    public User() {
    }

    public User(String name) {
        this.name = name;
    }
    //endregion

    //region getter and setter
    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    //endregion

    @Override
    public String toString() {
        return String.format("%d: %s", id, name);
    }

}

5.2. UserDto

Dto’s (data transfer objects) werden verwendet, um mehrere Daten (entities) in einem einzigen (teuren) Aufruf zu bündeln. Ein weiterer Vorteil ist, dass ev. vertrauliche Daten der Entities nicht exponiert werden. (siehe auch 1, 2, 3)

package at.htl.leonding.demo.entity.user;

public record UserDto (int id, String name) { }

5.3. UserMapper

package at.htl.leonding.demo.entity.user;

import javax.enterprise.context.ApplicationScoped;

@ApplicationScoped
public class UserMapper {
    public UserDto toResource(User user) {
        return new UserDto(user.getId(), user.getName());
    }
}

5.4. UserRepository

package at.htl.leonding.demo.entity.user;

import io.quarkus.hibernate.orm.panache.PanacheRepository;
import javax.enterprise.context.ApplicationScoped;

@ApplicationScoped
public class UserRepository implements PanacheRepository<User> {
}

5.5. UserResource

Beachte die Anzeige der Rückgabetypen von IntelliJ. Daher sind die Zeilenschaltungen sehr vorteilhaft

package at.htl.leonding.demo.entity.user;

import javax.inject.Inject;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import java.util.List;
import java.util.stream.Collectors;

@Path("/user")
public class UserResource {
    @Inject
    UserRepository userRepository;

    @Inject
    UserMapper userMapper;

    @GET
    public List<UserDto> getUsers() {
        return userRepository
                .findAll()
                .stream()
                .map(
                        user -> userMapper.toResource(user)
                )
                .collect(Collectors.toList());
    }
}

6. Run App

Terminal

./postgres-start.sh

output

[INFO] Scanning for projects...
[INFO]
[INFO] --------------------< at.htl.leonding.demo:backend >--------------------
[INFO] Building backend 1.0.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-clean-plugin:2.5:clean (default-clean) @ backend ---
[INFO] Deleting /Users/stuetz/work/2023-quarkus-ph-seminar/_tag2/backend/target
[INFO]
[INFO] --- quarkus-maven-plugin:2.16.4.Final:dev (default-cli) @ backend ---
[INFO] Invoking org.apache.maven.plugins:maven-resources-plugin:2.6:resources @ backend
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 3 resources
[INFO] Invoking io.quarkus.platform:quarkus-maven-plugin:2.16.4.Final:generate-code @ backend
[INFO] Invoking org.apache.maven.plugins:maven-compiler-plugin:3.10.1:compile @ backend
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 6 source files to /Users/stuetz/work/2023-quarkus-ph-seminar/_tag2/backend/target/classes
[INFO] Invoking org.apache.maven.plugins:maven-resources-plugin:2.6:testResources @ backend
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /Users/stuetz/work/2023-quarkus-ph-seminar/_tag2/backend/src/test/resources
[INFO] Invoking io.quarkus.platform:quarkus-maven-plugin:2.16.4.Final:generate-code-tests @ backend
[INFO] Invoking org.apache.maven.plugins:maven-compiler-plugin:3.10.1:testCompile @ backend
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to /Users/stuetz/work/2023-quarkus-ph-seminar/_tag2/backend/target/test-classes
Listening for transport dt_socket at address: 5005
Hibernate:

    drop table if exists TB_USER cascade
__  ____  __  _____   ___  __ ____  ______
 --/ __ \/ / / / _ | / _ \/ //_/ / / / __/
 -/ /_/ / /_/ / __ |/ , _/ ,< / /_/ /\ \
--\___\_\____/_/ |_/_/|_/_/|_|\____/___/
2023-03-04 13:55:24,750 WARN  [org.hib.eng.jdb.spi.SqlExceptionHelper] (JPA Startup Thread) SQL Warning Code: 0, SQLState: 00000

2023-03-04 13:55:24,751 WARN  [org.hib.eng.jdb.spi.SqlExceptionHelper] (JPA Startup Thread) table "tb_user" does not exist, skipping
Hibernate:

    create table TB_USER (
       id int8 generated by default as identity,
        name varchar(255),
        primary key (id)
    )

Hibernate:
    INSERT INTO public.tb_user (name) VALUES('Max Mustermann')
Hibernate:
    INSERT INTO public.tb_user (name) VALUES('Joe Sixpack')
Hibernate:
    INSERT INTO public.tb_user (name) VALUES('Jane Roe')
Hibernate:
    INSERT INTO public.tb_user (name) VALUES('John Doe')
2023-03-04 13:55:24,870 INFO  [io.quarkus] (Quarkus Main Thread) backend 1.0.0-SNAPSHOT on JVM (powered by Quarkus 2.16.4.Final) started in 1.778s. Listening on: http://localhost:8080
2023-03-04 13:55:24,871 INFO  [io.quarkus] (Quarkus Main Thread) Profile dev activated. Live Coding activated.
2023-03-04 13:55:24,871 INFO  [io.quarkus] (Quarkus Main Thread) Installed features: [agroal, cdi, hibernate-orm, hibernate-orm-panache, jdbc-postgresql, narayana-jta, resteasy, resteasy-jackson, smallrye-context-propagation, vertx, websockets, websockets-client]

--
Tests paused
Press [r] to resume testing, [o] Toggle test output, [:] for the terminal, [h] for more options>

7. Create Restful Client

http-requests/requests.http

GET {{local}}/user

###

8. Create Frontend-App

Latest stable npm version

node -v
npm -v

# npm install -g npm@9.6.0
npm install -g npm@latest

HtmlWebpackPlugin

8.1. Download frontend-scaffolding

curl -# -O http://edufs.edu.htl-leonding.ac.at/~t.stuetz/download/nvs/scripts/2023-03-quarkus-sem/frontend.zip

# if unzip is installed ...
unzip frontend.zip

cd frontend/www

npm install

npm update

npm start

http://localhost:4200

8.2. Download k8s-pipeline

download to the project-root and extract

curl -O -# http://edufs.edu.htl-leonding.ac.at/~t.stuetz/download/nvs/scripts/2023-03-quarkus-sem/k8s.zip