ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() #1981

foscraig · 2019-03-08T19:24:35Z

When trying to get the first private subnet in a IVpcNetwork, it returns a ClassCastException.
The relevant code:

  public static HashMap<String, String> getVpcInfo(IVpcNetwork vpc) {
    String vpcId = vpc.getVpcId();
    IVpcSubnet subnet = vpc.getPrivateSubnets().get(0);         // line 39
    HashMap<String, String> vpcInfo = new HashMap<>();
    vpcInfo.put("vpcId", vpcId);
    vpcInfo.put("subnetId", subnet.getSubnetId());
    vpcInfo.put("securityGroupId", getSecurityGroupId(vpcId));
    return vpcInfo;
  }

Runtime exception (cdk deploy):

Exception in thread "main" java.lang.ClassCastException: software.amazon.awscdk.Construct cannot be cast to software.amazon.awscdk.services.ec2.IVpcSubnet
        at com.amazonaws.emr.releasetool.infrastructure.VpcResourceUtilities.getVpcInfo(VpcResourceUtilities.java:39)
        at com.amazonaws.emr.releasetool.BigTopRpmBuildStack.build(BigTopRpmBuildStack.java:202)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.main(ReleaseBuildApp.java:47)
Subprocess exited with error 1

The text was updated successfully, but these errors were encountered:

eladb · 2019-03-12T08:32:39Z

I am unable to reproduce this on the latest release. What version are you using?

I believe this has been resolved by aws/jsii#321

foscraig · 2019-03-12T17:01:00Z

Could it be that I need to upgrade the toolkit? I upgraded my Maven dependencies but I'm realizing that I might need to upgrade the toolkit itself. That would definitely be a good thing to put in documentation if so because I don't know how right now. (I tried npm upgrade -g cdk.) I'm using 0.25.2 as a Maven dependency and cdk --version 0.20.0 (build cbeea75)

foscraig · 2019-03-12T17:12:31Z

Ok, I was using the wrong command. The upgrade is just npm install -g aws-cdk. Sorry, my bad. I do however still feel this should be emphasized in the docs.

foscraig · 2019-03-12T19:00:46Z

Sadly, upgrading did not resolve this. I am now using 0.25.3 and I get the same exception at runtime (using most up-to-date toolkit of same version).

foscraig · 2019-03-20T19:52:14Z

Similarly, when I've tried to use the following as a workaround, I still get the ClassCastException when trying to operate on this List of IVpcSubnets.

  private void createMountTarget(Stack stack, String fileSystemId) {
    VpcNetworkProviderProps vpcProps = VpcNetworkProviderProps.builder()
        .withVpcName(CODEBUILD_VPC_NAME)
        .build();
    IVpcNetwork vpc = VpcNetwork.importFromContext(stack, "Imported VPC", vpcProps);
    List<IVpcSubnet> subnets = vpc.subnets();
    IVpcSubnet privateSubnet = null;
    for (IVpcSubnet sub:subnets) {     \\ line 52
      if (sub.getNode().getAspects().contains(CODEBUILD_VPC_PRIVATE_SUBNET1)) {
        privateSubnet = sub;
      }
    }
    CfnMountTargetProps mountTargetProps = CfnMountTargetProps.builder()
        .withSubnetId(privateSubnet.getSubnetId())
        .withFileSystemId(fileSystemId)
        .build();
    CfnMountTarget mountTarget = new CfnMountTarget(stack, "User EFS MountTarget", mountTargetProps);
  }

returns this error:

java.lang.ClassCastException: software.amazon.awscdk.Construct cannot be cast to software.amazon.awscdk.services.ec2.IVpcSubnet
        at com.amazonaws.emr.releasetool.infrastructure.EfsResource.createMountTarget(EfsResource.java:52)
        at com.amazonaws.emr.releasetool.infrastructure.EfsResource.createEFS(EfsResource.java:39)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.createUserInfraStructure(ReleaseBuildApp.java:89)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.main(ReleaseBuildApp.java:39)
Exception in thread "main" java.lang.NullPointerException
        at com.amazonaws.emr.releasetool.BigTopRpm.createBuildStage(BigTopRpm.java:216)
        at com.amazonaws.emr.releasetool.BigTopRpm.<init>(BigTopRpm.java:106)
        at com.amazonaws.emr.releasetool.BigTopRpmBuilder.build(BigTopRpmBuilder.java:82)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.main(ReleaseBuildApp.java:63)

Without a workaround this blocks me from deploying.

rix0rrr · 2019-03-21T11:06:42Z

I bet this error is around returning the right type by the JSII kernel.

rix0rrr · 2019-03-21T11:09:34Z

Yes, fairly sure, since the actual class type is going to be ImportedVpcSubnet, and I recall not agreeing with the latest change that went into the selection of the type to return in that case.

rix0rrr · 2019-03-21T11:29:39Z

Hmm that does not seem to be it.

Could you run with the environment variable JSII_DEBUG=1 and paste the last 100 or so lines of the trace?

rix0rrr · 2019-03-21T11:33:30Z

Ah no, it IS that. It's just that this pull request: aws/jsii#346 just didn't fix the case where the return type is an array.

foscraig · 2019-03-21T16:10:00Z

Posting the element of the array (or for loop maybe? I guess) and after.

After that it seems to show it returning an array of Constructs.

[jsii-kernel] fromSandbox ImportedVpcSubnet {
  dependencyRoots: [ [Circular] ],
  node:
   ConstructNode {
     host: [Circular],
     aspects: [],
     _children: {},
     context: {},
     _metadata: [],
     references: Set {},
     dependencies: Set {},
     _locked: false,
     invokedAspects: [],
     id: 'PrivateSubnet4',
     scope:
      ImportedVpcNetwork {
        dependencyRoots: [Array],
        node: [ConstructNode],
        internetDependencies: [],
        natDependencies: [],
        props: [Object],
        vpcId: 'vpc-072e7c4e36bed379d',
        availabilityZones: [Array],
        vpnGatewayId: 'vgw-03788463cdcfa4e95',
        publicSubnets: [Array],
        privateSubnets: [Array],
        isolatedSubnets: [] } },
  props:
   { availabilityZone: 'us-west-2d',
     subnetId: 'subnet-068c09755c58d2c20' },
  internetConnectivityEstablished: ConcreteDependable { _dependencyRoots: [] },
  subnetId: 'subnet-068c09755c58d2c20',
  availabilityZone: 'us-west-2d' } undefined
[jsii-kernel] creating objref for ImportedVpcSubnet {
  dependencyRoots: [ [Circular] ],
  node:
   ConstructNode {
     host: [Circular],
     aspects: [],
     _children: {},
     context: {},
     _metadata: [],
     references: Set {},
     dependencies: Set {},
     _locked: false,
     invokedAspects: [],
     id: 'PrivateSubnet4',
     scope:
      ImportedVpcNetwork {
        dependencyRoots: [Array],
        node: [ConstructNode],
        internetDependencies: [],
        natDependencies: [],
        props: [Object],
        vpcId: 'vpc-072e7c4e36bed379d',
        availabilityZones: [Array],
        vpnGatewayId: 'vgw-03788463cdcfa4e95',
        publicSubnets: [Array],
        privateSubnets: [Array],
        isolatedSubnets: [] } },
  props:
   { availabilityZone: 'us-west-2d',
     subnetId: 'subnet-068c09755c58d2c20' },
  internetConnectivityEstablished: ConcreteDependable { _dependencyRoots: [] },
  subnetId: 'subnet-068c09755c58d2c20',
  availabilityZone: 'us-west-2d' }
< {"ok":{"result":[{"$jsii.byref":"@aws-cdk/cdk.Construct@10081"},{"$jsii.byref":"@aws-cdk/cdk.Construct@10082"},{"$jsii.byref":"@aws-cdk/cdk.Construct@10083"},{"$jsii.byref":"@aws-cdk/cdk.Construct@10084"}]}}
> {"api":"naming","assembly":"@aws-cdk/cdk"}
[jsii-kernel] naming @aws-cdk/cdk
< {"ok":{"naming":{"dotnet":{"assemblyOriginatorKeyFile":"../../key.snk","namespace":"Amazon.CDK","packageId":"Amazon.CDK","signAssembly":true},"java":{"maven":{"artifactId":"cdk","groupId":"software.amazon.awscdk"},"package":"software.amazon.awscdk"},"js":{"npm":"@aws-cdk/cdk"}}}}
> {"api":"naming","assembly":"@aws-cdk/cdk"}
[jsii-kernel] naming @aws-cdk/cdk
< {"ok":{"naming":{"dotnet":{"assemblyOriginatorKeyFile":"../../key.snk","namespace":"Amazon.CDK","packageId":"Amazon.CDK","signAssembly":true},"java":{"maven":{"artifactId":"cdk","groupId":"software.amazon.awscdk"},"package":"software.amazon.awscdk"},"js":{"npm":"@aws-cdk/cdk"}}}}
> {"api":"naming","assembly":"@aws-cdk/cdk"}
[jsii-kernel] naming @aws-cdk/cdk
< {"ok":{"naming":{"dotnet":{"assemblyOriginatorKeyFile":"../../key.snk","namespace":"Amazon.CDK","packageId":"Amazon.CDK","signAssembly":true},"java":{"maven":{"artifactId":"cdk","groupId":"software.amazon.awscdk"},"package":"software.amazon.awscdk"},"js":{"npm":"@aws-cdk/cdk"}}}}
> {"api":"naming","assembly":"@aws-cdk/cdk"}
[jsii-kernel] naming @aws-cdk/cdk
< {"ok":{"naming":{"dotnet":{"assemblyOriginatorKeyFile":"../../key.snk","namespace":"Amazon.CDK","packageId":"Amazon.CDK","signAssembly":true},"java":{"maven":{"artifactId":"cdk","groupId":"software.amazon.awscdk"},"package":"software.amazon.awscdk"},"js":{"npm":"@aws-cdk/cdk"}}}}
Exception in thread "main" java.lang.ClassCastException: software.amazon.awscdk.Construct cannot be cast to software.amazon.awscdk.services.ec2.IVpcSubnet
        at com.amazonaws.emr.releasetool.infrastructure.EfsResource.createMountTarget(EfsResource.java:57)
        at com.amazonaws.emr.releasetool.infrastructure.EfsResource.<init>(EfsResource.java:39)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.createUserInfraStructure(ReleaseBuildApp.java:108)
        at com.amazonaws.emr.releasetool.ReleaseBuildApp.main(ReleaseBuildApp.java:47)
Subprocess exited with error 1

Serialize and deserialize types according to their declared static type, and add validation on the runtime types matching the declared types. This is in contrast to previously, when we mostly only used the runtime types to determine what to do, and harly any validation was done. The runtime types used to be able to freely disagree with the declared types, and we put a lot of burden on the JSII runtimes at the other end of the wire. Fix tests that used to exercise the API with invalid arguments. Fixes aws/aws-cdk#1981.

Serialize and deserialize types according to their declared static type, and add validation on the runtime types matching the declared types. This is in contrast to previously, when we mostly only used the runtime types to determine what to do, and harly any validation was done. The runtime types used to be able to freely disagree with the declared types, and we put a lot of burden on the JSII runtimes at the other end of the wire. Fix tests that used to exercise the API with invalid arguments. Remove Proxy objects since they only existed to prevent accidentally overwriting certain keys via the jsii interface, and Symbols serve the same purpose (but simpler). Fixes aws/aws-cdk#1981.

### Bug Fixes * **kernel:** make type serialization explicit and recursive ([#401](#401)) ([0a83d52](0a83d52)), closes [aws/aws-cdk#1981](aws/aws-cdk#1981) * **runtime:** Passing 'this' to a callback from constructor ([#395](#395)) ([850f42b](850f42b))

foscraig changed the title ~~ClassCastException when trying to get an element from VpcNetwork.getPrivateSubnets()~~ ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() Mar 8, 2019

eladb added needs-response bug This issue is a bug. language/java Related to Java bindings labels Mar 12, 2019

rix0rrr self-assigned this Mar 25, 2019

rix0rrr mentioned this issue Mar 26, 2019

fix(kernel): make type serialization explicit and recursive aws/jsii#401

Merged

rix0rrr closed this as completed in aws/jsii#401 Mar 28, 2019

RomainMuller mentioned this issue Mar 28, 2019

v0.8.1 aws/jsii#406

Merged

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ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() #1981

ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() #1981

foscraig commented Mar 8, 2019

eladb commented Mar 12, 2019

foscraig commented Mar 12, 2019 •

edited

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foscraig commented Mar 12, 2019

foscraig commented Mar 12, 2019

foscraig commented Mar 20, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

foscraig commented Mar 21, 2019

ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() #1981

ClassCastException when trying to get an element from IVpcNetwork.getPrivateSubnets() #1981

Comments

foscraig commented Mar 8, 2019

eladb commented Mar 12, 2019

foscraig commented Mar 12, 2019 • edited Loading

foscraig commented Mar 12, 2019

foscraig commented Mar 12, 2019

foscraig commented Mar 20, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

rix0rrr commented Mar 21, 2019

foscraig commented Mar 21, 2019

foscraig commented Mar 12, 2019 •

edited

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