MigrationsRunner.java

package de.dlr.shepard.common.neo4j;

import ac.simons.neo4j.migrations.core.Migrations;
import ac.simons.neo4j.migrations.core.MigrationsConfig;
import ac.simons.neo4j.migrations.core.MigrationsConfig.VersionSortOrder;
import io.quarkus.logging.Log;
import jakarta.annotation.Nullable;
import java.nio.file.Path;
import org.eclipse.microprofile.config.ConfigProvider;
import org.neo4j.driver.AuthTokens;
import org.neo4j.driver.Driver;
import org.neo4j.driver.GraphDatabase;

public class MigrationsRunner {

  private final Migrations migrations;
  private final Driver driver;

  public MigrationsRunner() {
    this(null);
  }

  public MigrationsRunner(@Nullable String targetVersion) {
    String username = ConfigProvider.getConfig().getValue("neo4j.username", String.class);
    String password = ConfigProvider.getConfig().getValue("neo4j.password", String.class);
    String host = "neo4j://" + ConfigProvider.getConfig().getValue("neo4j.host", String.class);
    driver = GraphDatabase.driver(host, AuthTokens.basic(username, password));

    var config = MigrationsConfig.builder()
      .withTransactionMode(MigrationsConfig.TransactionMode.PER_STATEMENT)
      .withPackagesToScan("de.dlr.shepard.common.neo4j.migrations")
      // scan for the migrations specified by Cypher or XML files
      .withLocationsToScan("classpath:neo4j/migrations")
      .withResourceScanner(null)
      .withVersionSortOrder(VersionSortOrder.SEMANTIC)
      .withTarget(targetVersion)
      .build();

    migrations = new Migrations(config, driver);
  }

  public void waitForConnection() {
    while (true) {
      try {
        driver.verifyConnectivity();
        break;
      } catch (Exception e) {
        Log.warn("Cannot connect to neo4j database. Retrying...");
      }
      try {
        Thread.sleep(1000);
      } catch (InterruptedException e) {
        Log.error("Cannot sleep while waiting for neo4j Connection");
        Thread.currentThread().interrupt();
      }
    }
  }

  public void apply() {
    migrations.apply();
  }
}