MigrationsRunner.java
package de.dlr.shepard.neo4j;
import ac.simons.neo4j.migrations.core.Migrations;
import ac.simons.neo4j.migrations.core.MigrationsConfig;
import ac.simons.neo4j.migrations.core.MigrationsException;
import io.quarkus.logging.Log;
import java.nio.file.Paths;
import org.eclipse.microprofile.config.ConfigProvider;
import org.neo4j.driver.AuthTokens;
import org.neo4j.driver.Driver;
import org.neo4j.driver.GraphDatabase;
import org.neo4j.driver.exceptions.ServiceUnavailableException;
public class MigrationsRunner {
private Migrations migrations;
private Driver driver;
public MigrationsRunner() {
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));
// This is a workaround to make all migrations available in a dockerized quarkus jar.
// See https://gitlab.com/dlr-shepard/shepard/-/issues/146 for more information
var localPath = this.getClass().getClassLoader().getResource("neo4j/migrations").toString();
var dockerPath = Paths.get("/deployments/neo4j/migrations").toAbsolutePath().toString();
var isDocker = localPath.startsWith("jar");
var locationsToScan = isDocker ? dockerPath : localPath;
var config = MigrationsConfig.builder()
.withTransactionMode(MigrationsConfig.TransactionMode.PER_STATEMENT)
.withPackagesToScan("de.dlr.shepard.neo4j.migrations")
.withLocationsToScan("file://" + locationsToScan)
.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() {
try {
migrations.apply();
} catch (ServiceUnavailableException e) {
Log.error("Migrations cannot be executed because the neo4j database is not available");
} catch (MigrationsException e) {
Log.error("An error occurred during the execution of the migrations: ", e);
}
}
}