Function aws_util::kinesis::get_shard_iterator

pub async fn get_shard_iterator(
    client: &KinesisClient, 
    stream_name: &str, 
    shard_id: &str
) -> Result<Option<String>, Error>

Wrapper around AWS Kinesis GetShardIterator API (and Rusoto).

This function returns the TRIM_HORIZON shard iterator of a given stream and shard, meaning it will return the location in the shard with the oldest data record. We use this to connect to newly discovered shards.

Does not currently handle any GetShardIterator errors, will return all errors directly to the caller.