SNS: missing field `SigningCertUrl

[ymwjbxxq]

Take this simple Lambda:
https://serverlessland.com/patterns/sns-sqs-lambda-sam-rust (the code is not up to date but 8 months ago it was working)

If you update the code and the libs

use aws_lambda_events::event::{sns::SnsMessage, sqs::SqsEvent};
use futures::future::join_all;
use lambda_runtime::{service_fn, Error, LambdaEvent};
use serde::Deserialize;

#[tokio::main]
async fn main() -> Result<(), Error> {
    tracing_subscriber::fmt()
        .with_ansi(false)
        .without_time()
        .init();

    lambda_runtime::run(service_fn(|event: LambdaEvent<SqsEvent>| execute(event))).await?;

    Ok(())
}

pub async fn execute(event: LambdaEvent<SqsEvent>) -> Result<(), Error> {
    println!("Input {:?}", event);

    let mut tasks = Vec::with_capacity(event.payload.records.len());
    for record in event.payload.records.into_iter() {
        tasks.push(tokio::spawn(async move {
            if let Some(body) = &record.body {
                let sns_message = serde_json::from_str::<SnsMessage>(&body).unwrap();
                let sns_message = sns_message.message;
                let request = serde_json::from_str::<MyStruct>(&sns_message);
                if let Ok(request) = request {
                    // Do something
                    println!("Request {:?}", request);
                }
            }
        }));
    }

    join_all(tasks).await;

    Ok(())
}

#[derive(Deserialize, Debug, Clone, PartialEq, Eq)]
pub struct MyStruct {
    pub name: String,
    pub surname: String,
}

cargo.toml

[package]
name = "sns-sqs-lambda-rust"
version = "0.1.0"
edition = "2021"

# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

[[bin]]
name = "handler"
path = "src/bin/handler.rs"

[dependencies]
aws_lambda_events = { version = "0.7.2", default-features = false, features = ["sqs", "sns"] }
futures = "0.3.17"
lambda_runtime = "0.7.2"
serde = {version = "1.0", features = ["derive"] }
serde_json = "1.0.68"
simple-error = "0.2"
tokio = { version = "1", features = ["full"] }
tracing-subscriber = "0.3"

You get an exception:
`Input LambdaEvent { payload: SqsEvent { records: [SqsMessage { message_id: Some("44dec5ec-0128-4661-9c54-a06485ead572"), receipt_handle: Some(".....="), body: Some("{\n "Type" : "Notification",\n "MessageId" : "5a1c0085-ee71-5e38-9d84-5c9bdcb02ad5",\n "TopicArn" : "arn:aws:sns:eu-central-1:xxxxx:sam-app-MySnsTopic-BWiabVkXTYg2",\n "Message" : "{\n \"name\": \"Daniele\",\n \"surname\": \"Frasca\"\n}",\n "Timestamp" : "2022-12-22T10:25:05.377Z",\n "SignatureVersion" : "1",\n "Signature" : ".....==",\n "SigningCertURL" : "https://sns.eu-central-1.amazonaws.com/SimpleNotificationService-56e67fcb41f6fec09b0196692625d385.pem",\n "UnsubscribeURL" : "https://sns.eu-central-1.amazonaws.com/?Action=Unsubscribe&SubscriptionArn=arn:aws:sns:eu-central-1:xxxxx:sam-app-MySnsTopic-BWiabVkXTYg2:44fb3b0d-6b6a-48cc-9183-f52a3d238175"\n}"), md5_of_body: Some("ab0cac5be52987991d1d1b2b57a08480"), md5_of_message_attributes: None, attributes: {"SentTimestamp": "1671704705405", "SenderId": "AIDAISDDSWNBEXIA6J64K", "ApproximateFirstReceiveTimestamp": "1671704705410", "ApproximateReceiveCount": "1"}, message_attributes: {}, event_source_arn: Some("arn:aws:sqs:eu-central-1:xxxxx:sam-app-MySqsQueue-nDLzmzS8vEaH"), event_source: Some("aws:sqs"), aws_region: Some("eu-central-1") }] }, context: Context { request_id: "d187ab64-f92b-52a2-a81b-f77acb9cde03", deadline: 1671704735726, invoked_function_arn: "arn:aws:lambda:eu-central-1:xxxxxx:function:sam-app-MyFunction-QqyqP0mMMxOS", xray_trace_id: Some("Root=1-63a43081-22df4f205924b3de2b0c3b46;Parent=54651cb434f944d8;Sampled=0"), client_context: None, identity: None, env_config: Config { function_name: "sam-app-MyFunction-QqyqP0mMMxOS", memory: 128, version: "$LATEST", log_stream: "2022/12/22/[$LATEST]7da35658a61a4b0cb323242f7f20526a", log_group: "/aws/lambda/sam-app-MyFunction-QqyqP0mMMxOS" } } }

thread 'tokio-runtime-worker' panicked at 'called Result::unwrap() on an Err value: Error("missing field SigningCertUrl", line: 11, column: 1)', src/bin/handler.rs:29:77

`

Please let me know if it is not clear.

[calavera]

oh, that's weird, the field is here:

aws-lambda-events/aws_lambda_events/src/sns/mod.rs

Line 143 in ca3f8e2

#[serde(rename = "SigningCertURL")]

I'm guessing case sensitive issues 🤦

[ymwjbxxq]

It happens.

SigningCertUrl
SigningCertURL

I did not see it as well at first look.

[ymwjbxxq]

On the readme:
We have no desire to manually write event definitions and contributions to that effect will not be accepted. If the [official Go SDK](https://github.com/aws/aws-lambda-go/tree/master/events) is missing an event definition, please file a bug on that project rather than submitting a fix here. Once the official Go SDK has included your changes this project will pick up the new event definitions.

In GO I can see it is correct:
https://github.com/aws/aws-lambda-go/blob/99a9a4bd72b603da8d75d74d77937c146fed0b7c/events/sns.go#L28

I also see that what they call SNSEntity here is called SnsMessage. If it is all generated automatically, I need to find out where the name change is.

Another thing that I see is:
#[serde(rename_all = "PascalCase")]

So, in theory, this SigningCertURL should be SigningCertUrl.

Can you explain to me how to fix it? I think I cannot directly change the aws-lambda-events/aws_lambda_events/src/sns/mod.rs

[calavera]

Can you explain to me how to fix it? I think I cannot directly change the aws-lambda-events/aws_lambda_events/src/sns/mod.rs

Yes, you can modify that file directly. Only the ones in the generated directory are generated from Go. Make sure you update the test examples too.

[calavera]

I just released 0.8.2 with the fix. Thank you all.