R2DBC 和 liquibase

Question

So starting a new project and i want to use r2dbc and webflux, been looking into what support there is to handle database migration. The last answer i could find here was from july 2019 that liquibase does not support R2DBC and after googling, this seems to still be the case.

The dream would be to use r2dbc-h2 while developing locally, and then use something like postgres during production. Liquibase would manage the table structure both locally and in production.

Been trying to google a bit about how such a setup would look like and there is very little information out there.

I have been thinking about setting up the tables using the liquibase-maven-plugin , but i don't know if that will work with r2dbc-h2 .

So several questions:

• How to setup so that liquibase uses a regular driver during migration, while the rest of the application uses the reactive driver?
• if using the maven plugin can this be used with H2 or do i need postgres as a docker?

This is a very black hole for me, does any have any information?

Answer 1

I think there should be no problem using 2 drivers in application. As liquibase uses standard jdbc driver you can configure it to use that one for migrations and configure r2dbc to run the application. Maybe some tweeks needs to be done but I would start with something like:

spring:
  liquibase:
    url: jdbc:postgresql://localhost:5432/mydb
    user: postgres
  r2dbc:
    url: r2dbc:postgresql://localhost:5432/mydb
    username: postgres

and include both libraries:

io.r2dbc:r2dbc-postgresql
org.postgresql:postgresql

If there is error keep us posted.

note: for testing you can use testcontainers or embedded postgresql also

Answer 2

Complementing @bilak's answer, you must add the following dependency to your pom.xml:

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

I was facing the same problem and I had added the properties user and URL to Liquibase configuration on my application.yml, and then Spring started to claim about one class not found, adding this dependency solved the issue

Answer 3

As of Spring Boot 2.6.3 with Spring Framework 5.3.15, the following configuration works for R2DBC with Liquibase

build.gradle snippet

dependencies {
    implementation 'org.springframework.boot:spring-boot-starter-data-r2dbc'
    implementation 'org.springframework.boot:spring-boot-starter-webflux'

    //database
    implementation "io.r2dbc:r2dbc-postgresql"
    runtimeOnly 'org.postgresql:postgresql'

    //liquibase
    implementation "org.liquibase:liquibase-core"
    runtimeOnly 'org.springframework:spring-jdbc'

    testImplementation 'io.projectreactor:reactor-test'
}

application.yml

spring:
  main:
    web-application-type: REACTIVE
  r2dbc:
    url: r2dbc:postgresql://localhost/mydb
    username: postgres
  liquibase:
    url: jdbc:postgresql://localhost/mydb