NullPointerException in FlywayEndpoint with schema baseline

[gbehrmann]

Spring Boot 2.0.4

In case a Flyway managed schema has a baseline, migrations prior to the baseline are not considered as applied by Flyway. As a result org.flyway.core.api.MigrationInfo#getInstalledOn returns null. This triggers a NullPointerException in the org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayMigration constructor when the installation time is to be converted to an Instant:

		private FlywayMigration(MigrationInfo info) {
			this.type = info.getType();
			this.checksum = info.getChecksum();
			this.version = nullSafeToString(info.getVersion());
			this.description = info.getDescription();
			this.script = info.getScript();
			this.state = info.getState();
			this.installedBy = info.getInstalledBy();
			this.installedOn = Instant.ofEpochMilli(info.getInstalledOn().getTime());
			this.installedRank = info.getInstalledRank();
			this.executionTime = info.getExecutionTime();
		}

Stack Trace

Caused by: java.lang.NullPointerException: null
        at org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayMigration.(FlywayEndpoint.java:167)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayMigration.(FlywayEndpoint.java:137)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayDescriptor.lambda$new$0(FlywayEndpoint.java:120)
        at java.base/java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:195)
        at java.base/java.util.Spliterators$ArraySpliterator.forEachRemaining(Spliterators.java:948)
        at java.base/java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:484)
        at java.base/java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:474)
        at java.base/java.util.stream.ReduceOps$ReduceOp.evaluateSequential(ReduceOps.java:913)
        at java.base/java.util.stream.AbstractPipeline.evaluate(AbstractPipeline.java:234)
        at java.base/java.util.stream.ReferencePipeline.collect(ReferencePipeline.java:578)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayDescriptor.(FlywayEndpoint.java:121)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint$FlywayDescriptor.(FlywayEndpoint.java:115)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint.lambda$flywayBeans$0(FlywayEndpoint.java:59)
        at java.base/java.util.LinkedHashMap.forEach(LinkedHashMap.java:684)
        at org.springframework.boot.actuate.flyway.FlywayEndpoint.flywayBeans(FlywayEndpoint.java:58)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:223)
        at org.springframework.boot.actuate.endpoint.invoke.reflect.ReflectiveOperationInvoker.invoke(ReflectiveOperationInvoker.java:76)
        at org.springframework.boot.actuate.endpoint.annotation.AbstractDiscoveredOperation.invoke(AbstractDiscoveredOperation.java:61)
        at org.springframework.boot.actuate.endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$ServletWebOperationAdapter.handle(AbstractWebMvcEndpointHandlerMapping.java:243)
        at org.springframework.boot.actuate.endpoint.web.servlet.AbstractWebMvcEndpointHandlerMapping$OperationHandler.handle(AbstractWebMvcEndpointHandlerMapping.java:299)
        at jdk.internal.reflect.GeneratedMethodAccessor44.invoke(Unknown Source)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209)
        at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
        at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
        at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
        at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
        at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
        at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
        at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
        ... 92 common frames omitted

[eddumelendez]

I could reproduce the issue and found something interesting

My steps were the following:

1. Initialize a database with a initial table
2. Perform flyway baseline version 1
3. Create a spring boot project with 3 scripts: V1__init.sql, V2__init.sql, V3__init.sql. Also, the following properties were added spring.flyway.baseline-version=2, spring.flyway.baseline-on-migrate=true
4. Access to flyway endpoint and the failure was expected for the reason explined by @gbehrmann

As you can see in the steps I followed, baseline version 1 was created and also a sql file V1__init.sql was added for migration. Flyway will read all sql scripts (including V1__init.sql) and it will try to perform all sql scripts and get the installedOn for each of them. But, since spring.flyway.baseline-version=2 was set, V1__init.sql will be ignored or will not be inserted into the table which will not retrieve the installedOn field.

Just fixed renaming the scripts to V3__init.sql, V4__init.sql, V5__init.sql

One suggestion for spring-boot side would be:

1. Add filter with installedOn different to null in FlywayEndpoint

private FlywayDescriptor(MigrationInfo[] migrations) {
    this.migrations = Stream.of(migrations).map(FlywayMigration::new)
		.collect(Collectors.toList());
}

WDYT?

[wilkinsona]

@eddumelendez Thanks for the suggestion. I think it's useful for the endpoint to show migrations that Flyway was aware of but chose not to run. If we filter out migrations with a null installedOn we'll lose that information.

[wilkinsona]

Closing in favour of PR #14019.