how to get values to spring.boot.admin.client.username/ password from database?

Question

I have spring boot admin project and now I hardcoded the username and passwords in application.properties file like this.

spring.boot.admin.client.username=user
spring.boot.admin.client.password=pass

spring.boot.admin.client.instance.metadata.user.name=user
spring.boot.admin.client.instance.metadata.user.password=pass

But want to get that values from database not hardcoded like this.I want to configs to connect to self register the admin server as a client.I am beginner to SpringBoot. How can I do it? Thanks.

Answer 1

So every configuration in an application.properties file can be configured via Javacode. First you have to create a Datasource for your project. Add the spring-data-jpa dependency to your project and config the datasource.

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>

more you can find here: A Guide to JPA with Spring

To configure for example the two properties spring.boot.admin.client.username=user and spring.boot.admin.client.password=pass you need to create a @Configuration class which creates a ClientProperties Bean.

@Configuration
public class AdminClientConfig {

    private final JdbcTemplate jdbcTemplate;
    private final Environment environment;

    public AdminClientConfig(JdbcTemplate jdbcTemplate,
        Environment environment) {
        super();
        this.jdbcTemplate = jdbcTemplate;
        this.environment = environment;
    }

    @Bean
    public ClientProperties clientProperties() {
        ClientProperties cp = new ClientProperties(environment);

        cp.setUsername(getUsername());
        cp.setPassword(getPassword());

        return cp;
    }

    private String getUsername() {
        String username = jdbcTemplate.queryForObject(
            "select username from AnyTable where id = ?",
            new Object[] { "123" }, String.class);
        return username;
    }

    private String getPassword() {
        String password = jdbcTemplate.queryForObject(
            "select password from AnyTable where id = ?",
            new Object[] { "123" }, String.class);
        return password;
    }
}

So the JdbcTemplate has already a Database connection and creates the query to get the Username and Password from the Database. The ClientProperties Bean can then be set.

P.S.: This code is not tested but gives you a some hints to get the job done.