AWS SAM local invocation of lambda to access AWS Neptune over VPC

Question

I need to be able to invoke a lambda locally which accesses AWS Neptune. I have setup SSH local forwarding via an EC2. How do I make this work inside lambda with sam local invoke?

Accepted Answer

The solution here may depend on what OS you're using for your desktop and where you are running the SAM CLI.  Docker behaves a bit differently in each OS.  Running on MacOS, I can reach the SSH tunnel if I use `'wss://docker.for.mac.localhost:8182/gremlin'` as my Neptune endpoint (just change `gremlin` to `oc` or `sparql` for the other languages).  I believe this also works with `host.docker.internal` as a more generic host name that forwards back to `localhost` on your desktop OS.

The other thing you'll need to consider is SSL verification.  Neptune no longer allows you to disable SSL on the cluster side.  If you're just doing this for test/development, you can ignore SSL verification.  For Gremlin specifically, you can do this by adding a `verify_ssl=False` parameter when creating the DriverRemoteConnection:

```
conn = DriverRemoteConnection(neptune_endpoint, 'g', pool_size=1, message_serializer=serializer.GraphSONSerializersV2d0(), verify_ssl=False)
g = traversal().withRemote(conn)
```

AWS SAM local invocation of lambda to access AWS Neptune over VPC

Conteúdo relevante