Confusing interface of no_credentials() for config

[ivan-kiselev]

Describe the bug

So, I am not quite sure it's a bug or intended, but I am trying to use locally running DynamoDB provided by NoSQL workbench for integration testing and general development loop, thus I need to connect SDK to the http://localhost:8000 instance of DynamoDB.

I tried to play with no_credentials() thing for a little while, but it doesn't really workout with the following error:

called `Result::unwrap()` on an `Err` value: DispatchFailure(DispatchFailure { source: ConnectorError { kind: Other(None), source: NoMatchingAuthScheme, connection: Unknown } })

And in the same time, shall I introduce silly Credentials provider, it will work alright.

use aws_sdk_dynamodb::config::Credentials;

fn create_my_credential_provider() -> Credentials {
    Credentials::new("example", "example", None, None, "example")
}

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();
    let cfg = aws_config::defaults(aws_config::BehaviorVersion::latest())
        .endpoint_url("http://localhost:8000")
        .region("eu-west-1")
        // .no_credentials() <- doesn't work
        .credentials_provider(create_my_credential_provider()) // <- works, but kinad silly and feels like should be covered by .no_credentials() instead
        .load()
        .await;

    let cfg = aws_sdk_dynamodb::Config::new(&cfg);
    let client = aws_sdk_dynamodb::Client::from_conf(cfg);
    let response = client.list_tables().send().await.unwrap();
    for table in response.table_names().iter() {
        println!("Found table {}", table)
    }
}

Now, as much as there's though seemingly silly, but robust workaround, it does feel that implementation of .no_credentials() is somehow incomplete and this use-case shall be covered by it.

As in, I, as a user of the sdk, when seen this method - it seemed natural for me to assume that it is exactly what I need, but somehow it was not.

Also, if I am doing something fundamentally wrong, I am happy to stand corrected.

Expected Behavior

Either no_credentials() on on aws_config::ConfigLoader removes any checks/validations for authentication from any client build with such config, or maybe it shall be renamed to something a bit more narrow if it was not the intent for the method.

Current Behavior

For dynamodb, at least, when building client with .no_credentials() config, one gets an error:

called `Result::unwrap()` on an `Err` value: DispatchFailure(DispatchFailure { source: ConnectorError { kind: Other(None), source: NoMatchingAuthScheme, connection: Unknown } })

Reproduction Steps

Run the following snippet with locally running DynamoDB

#[tokio::main]
async fn main() {
    tracing_subscriber::fmt::init();
    let cfg = aws_config::defaults(aws_config::BehaviorVersion::latest())
        .endpoint_url("http://localhost:8000")
        .region("eu-west-1")
        .no_credentials() <- doesn't work
        .load()
        .await;

    let cfg = aws_sdk_dynamodb::Config::new(&cfg);
    let client = aws_sdk_dynamodb::Client::from_conf(cfg);
    let request = client.list_tables().send().await.unwrap();
    for table in request.table_names().iter() {
        println!("Found table {}", table)
    }
}

Possible Solution

No response

Additional Information/Context

No response

Version

[dependencies]
aws-config = "1.0.0"
aws-sdk-dynamodb = { version = "0.39.0", features = ["behavior-version-latest"] }
tokio = { version = "1.34.0", features = ["full"] }
tracing-subscriber = "0.3.18"

### Environment details (OS name and version, etc.)

MacOS 14.1.1 (23B81) ❯ uname -a Darwin hehe.local 23.1.0 Darwin Kernel Version 23.1.0: Mon Oct  9 21:28:31 PDT 2023; root:xnu-10002.41.9~6/RELEASE_ARM64_T8112 arm64

### Logs

_No response_

[rcoh]

Dynamo isn't configured to work with no credentials (this is required to be modeled behavior). As the docs of no_credentials say, this is a very specific behavior that actually fully disables authentication (when allowed by the model).

Another option is Credentials::for_tests()

note that this will require enabling the test-util feature

[rcoh]

We should clarify the documentation of no_credentials, at the very least.

[ivan-kiselev]

Well, one would use absence of auth in testing purposes anyways, so enabling test-util is completely fine.

Can confirm that Credentials::for_tests() works just fine.

[jdisanti]

The fix for this has been merged and will go out in an upcoming release.

[jdisanti]

The fix for this went out in the December 14th release.

[github-actions]

⚠️COMMENT VISIBILITY WARNING⚠️

Comments on closed issues are hard for our team to see.
If you need more assistance, please either tag a team member or open a new issue that references this one.
If you wish to keep having a conversation with other community members under this issue feel free to do so.