# AWS clients for Erlang
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[](https://hex.pm/packages/aws_erlang)
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[](https://github.com/aws-beam/aws-erlang/blob/master/LICENSE.md)
[](https://github.com/aws-beam/aws-erlang/commits/master)
:rocket: Create, configure, and manage AWS services from Erlang code. :rocket:
## Features
* A clean API separated per service. One module per service.
* Support for most of the AWS services.
* Generated by [aws-codegen](https://github.com/aws-beam/aws-codegen) using the
same JSON descriptions of AWS services used to build the
[AWS SDK for Go](https://github.com/aws/aws-sdk-go/tree/master/models/apis).
* Documentation updated from the official AWS docs.
## Usage
Here is an example of listing Amazon Kinesis streams. First of all,
start a shell with `rebar3 shell`, then:
### aws_s3
Here is another example, this time using a _temporary_ client, showing
how to upload a file to _S3_ and how to fetch it back:
```erlang
> Client = aws_client:make_temporary_client(<<"my-access-key-id">>, <<"my-secret-access-key">>, <<"my-token">>, <<"eu-west-1">>).
[...]
> {ok, Content} = file:read_file("/tmp/erlang-logo.png").
[...]
> aws_s3:put_object(Client, <<"my-bucket">>, <<"my-key">>, #{<<"Body">> => Content}).
[...]
> {ok, Response, _} = aws_s3:get_object(Client, <<"my-bucket">>, <<"my-key">>).
[...]
> Content = maps:get(<<"Body">>, Response).
```
Support for creating [Presigned URLs](https://docs.aws.amazon.com/AmazonS3/latest/userguide/ShareObjectPreSignedURL.html) is provided
through the `aws_s3_presigned_url` module.
### aws_kinesis
```erlang
> Client = aws_client:make_client(<<"my-access-key-id">>, <<"my-secret-access-key">>, <<"eu-west-1">>),
[...]
> {ok, Result, _Response} = aws_kinesis:list_streams(Client, #{}),
[...]
> io:format("~p~n", [Result]).
#{<<"HasMoreStreams">> => false,<<"StreamNames">> => []}
```
### AWS RDS IAM Token Creation
Support for creating IAM Tokens (more info [here](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/UsingWithRDS.IAMDBAuth.Connecting.html)) has been added as part of the `aws_rds_iam_token` module.
This allows for easy creation of RDS/Aurora tokens to be used for IAM based authentication instead of username/password combination.
```erlang
> Client = aws_client:make_temporary_client(<<"AccessKeyID">>, <<"SecretAccessKey">>, <<"Token">>, <<"eu-west-1">>).
[...]
> {ok, Url} = create(Client, <<"db_endpoint">>, 5432, <<"db_user">>).
[...]
```
This token can subsequently be used to connect to the database over IAM.
### retry options
Each API which takes `Options` allows a `retry_options` key and can allow for automatic retries.
Simple provide the following:
`[{retry_options, {exponential_with_jitter, {MaxAttempts, BaseSleepTime, CapSleepTime}}} | <other_options>]`
This implementation is based on [AWS: Exponential Backoff And Jitter](https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/).
## Installation
Simply add the library to your `rebar.config`:
```erlang
{deps, [{aws, "1.0.0", {pkg, aws_erlang}}]}.
```
## Obtaining Credentials
Credentials can be obtained via the separate [aws_credentials](https://github.com/aws-beam/aws_credentials) application, which can be configured to fetch credentials from:
* Erlang environment variables
* OS environment variables
* An AWS credentials file
* ECS task credentials
* EC2 metadata (including v2 - IMDS)
Here is an example on how to obtain credentials:
```erlang
> Credentials = aws_credentials:get_credentials().
[...]
> #{ access_key_id := AccessKeyId
, token := Token
, region := Region
, secret_access_key := SecretAccessKey } = Credentials.
```
The `aws_credentials` application can be installed by adding the following to your `rebar.config`:
```erlang
{deps, [{aws_credentials, "0.1.10"}]}.
```
## Development
The service-specific modules are generated using the [aws-codegen](https://github.com/aws-beam/aws-codegen) library from the JSON descriptions of AWS services provided by Amazon.
The rest of the code is manually written and used as support for the generated code.
## Documentation
### Check it Online
* [Hex Docs](https://hexdocs.pm/aws_erlang/)
### Build it locally
```bash
$ rebar3 ex_doc
```
The docs will be available in `./doc`.
## Running Tests
```bash
$ rebar3 eunit
```
```bash
$ docker-compose -f test/docker/docker-compose.yml up -d
$ rebar3 ct
$ docker-compose -f test/docker/docker-compose.yml down
```
## License
Copyright 2015 Jamshed Kakar <jkakar@kakar.ca>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
