Flyway在Apache Karaf上找不到SQL迁移

Question

我们正在Karaf中部署我们的应用程序，并试图使用Flyway来处理数据库迁移，但它在运行时找不到我们的V#__*. sql文件。我检查过的东西：

>

Caused by: org.flywaydb.core.api.FlywayException: 
Unable to scan for SQL migrations in location: classpath:db/migration

当我为Flyway启用调试时，我可以看到它在类路径上找到了文件夹，但其中没有文件。

DEBUG|org.flywaydb.core.Flyway|408-org.flywaydb.core-3.2.1|DDL Transactions Supported: true
DEBUG|org.flywaydb.core.Flyway|408-org.flywaydb.core-3.2.1|Schema: my_database
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning for classpath resources at 'db/migration' (Prefix: '', Suffix: '.sql')
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning URL: bundle://418.0:1/db/migration
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v2 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v3 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|OSGi framework available: true
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|Spring Jdbc available: false
DEBUG|org.flywaydb.core.internal.command.DbValidate|408-org.flywaydb.core-3.2.1|Validating migrations ...
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning for classpath resources at 'db/migration' (Prefix: 'V', Suffix: '.sql')
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning URL: bundle://418.0:1/db/migration
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v2 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v3 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|OSGi framework available: true
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning for classes at 'db/migration' (Implementing: 'org.flywaydb.core.api.migration.jdbc.JdbcMigration')
DEBUG|org.flywaydb.core.internal.util.scanner.classpath.ClassPathScanner|408-org.flywaydb.core-3.2.1|Scanning URL: bundle://418.0:1/db/migration
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v2 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|JBoss VFS v3 available: false
DEBUG|org.flywaydb.core.internal.util.FeatureDetector|408-org.flywaydb.core-3.2.1|OSGi framework available: true
INFO|org.flywaydb.core.internal.command.DbValidate|408-org.flywaydb.core-3.2.1|Validated 0 migrations (execution time 00:00.010s)
DEBUG|org.flywaydb.core.internal.command.DbSchemas|408-org.flywaydb.core-3.2.1|Schema "my_database" already exists. Skipping schema creation.
DEBUG|org.flywaydb.core.internal.dbsupport.Table|408-org.flywaydb.core-3.2.1|Locking table "my_database"."schema_version"...
DEBUG|org.flywaydb.core.internal.dbsupport.Table|408-org.flywaydb.core-3.2.1|Lock acquired for table "my_database"."schema_version"
INFO|org.flywaydb.core.internal.command.DbMigrate|408-org.flywaydb.core-3.2.1|Current version of schema "my_database": << Empty Schema >>
INFO|org.flywaydb.core.internal.command.DbMigrate|408-org.flywaydb.core-3.2.1|Schema "my_database" is up to date. No migration necessary.

当408与安装的捆绑包匹配时，日志显示它正在查找正确的捆绑包。

我不确定还要查找什么，因为没有记录任何错误，而且它似乎正在查找它应该位于的文件夹，而不是sql文件。我假设这是一个清单类型问题，但我不确定要查找什么。接下来的步骤是什么？

Answer 1

通过部署一个片段包使其工作，并且片段主机被设置为org。flywaydb。果心请看一看我在https://github.com/barryku/karaf-flyway-demo.这个例子的灵感来自于https://github.com/FlavioF/fabric8-osgi-flyway-example/tree/master/fabric8-osgi-flyway.

Answer 2

这可能取决于你如何捆绑Flyway。

如果您将它嵌入到与迁移脚本相同的包中，它应该可以正常工作。

但是，如果您将flyway作为一个独立的包，则需要让它知道哪个类加载器包含资源。

一种技术是从包中包含迁移资源的类执行以下操作。

ClassLoader context = Thread.currentThread().getContextClassLoader();

try {
    Thread.currentThread().setContextClassLoader(this.getClass());

    Flyway flyway = new Flyway();
    flyway.setDataSource("jdbc:h2:file:target/foobar", "sa", null);
    flyway.clean();
    flyway.migrate();
}
finally {
    Thread.currentThread().setContextClassLoader(context);
}

Answer 3

OSGi和类路径扫描是一件棘手的事情，似乎在每个容器中的工作方式都不同。请在问题跟踪程序中提交问题。拉请求也欢迎。