Partial - this is the structure for S3 events

s3.rs

#[derive(Deserialize, Debug)]
struct S3Event {
    #[serde(rename = "Records")]
    #[allow(dead_code)]
    records: Vec<S3EventRecord>,
}

#[derive(Deserialize, Debug)]
struct S3EventRecord {
    #[serde(rename = "eventVersion")]
    #[allow(dead_code)]
    event_version: String,

    #[serde(rename = "eventSource")]
    #[allow(dead_code)]
    event_source: String,

    #[serde(rename = "awsRegion")]
    #[allow(dead_code)]
    aws_region: String,

    #[serde(rename = "eventTime")]
    #[allow(dead_code)]
    event_time: DateTime<Utc>,

    #[serde(rename = "eventName")]
    #[allow(dead_code)]
    event_name: String,

    #[serde(rename = "userIdentity")]
    #[allow(dead_code)]
    user_identity: S3UserIdentity,

    #[serde(rename = "requestParameters")]
    #[allow(dead_code)]
    request_parameters: S3RequestParameters,

    #[serde(rename = "responseElements")]
    #[allow(dead_code)]
    response_elements: HashMap<String, String>,

    #[serde(rename = "s3")]
    #[allow(dead_code)]
    s3: S3Entity,
}

#[derive(Deserialize, Debug)]
struct S3RequestParameters {
    #[serde(rename = "sourceIPAddress")]
    #[allow(dead_code)]
    source_ip_address: String,
}

#[derive(Deserialize, Debug)]
struct S3UserIdentity {
    #[serde(rename = "principalId")]
    #[allow(dead_code)]
    principal_id: String,
}

#[derive(Deserialize, Debug)]
struct S3Entity {
    #[serde(rename = "s3SchemaVersion")]
    #[allow(dead_code)]
    schema_version: String,

    #[serde(rename = "configurationId")]
    #[allow(dead_code)]
    configuration_id: String,

    #[serde(rename = "bucket")]
    #[allow(dead_code)]
    bucket: S3Bucket,

    #[serde(rename = "object")]
    #[allow(dead_code)]
    object: S3Object,
}

#[derive(Deserialize, Debug)]
struct S3Bucket {
    #[serde(rename = "name")]
    #[allow(dead_code)]
    name: String,

    #[serde(rename = "ownerIdentity")]
    #[allow(dead_code)]
    owner_identity: S3UserIdentity,

    #[serde(rename = "arn")]
    #[allow(dead_code)]
    arn: String,
}

#[derive(Deserialize, Debug)]
struct S3Object {
    #[serde(rename = "key")]
    #[allow(dead_code)]
    key: String,

    #[serde(default)]
    #[serde(rename = "size")]
    #[allow(dead_code)]
    size: i64,

    #[serde(default)]
    #[serde(rename = "urlDecodedKey")]
    #[allow(dead_code)]
    url_decoded_key: String,

    #[serde(default)]
    #[serde(rename = "versionId")]
    #[allow(dead_code)]
    version_id: String,

    #[serde(default)]
    #[serde(rename = "eTag")]
    #[allow(dead_code)]
    etag: String,

    #[serde(rename = "sequencer")]
    #[allow(dead_code)]
    sequencer: String,
}