Tuesday, 19 November 2019

How to access Amazon Web Services via AWS Go SDK

The centre point of the AWS client application is AWS Session. To create it, we need to do the following:

(1) import github.com/aws/aws-sdk-go/aws/session package
(2) call NewSession() on it

sess, err := session.NewSession()

By default, session uses environment variables for its configuration. Some of them are:

AWS_ACCESS_KEY_ID
AWS_SECRET_ACCESS_KEY
AWS_REGION

For the full list see AWS CLI - Environment Variables.

So, if we call our AWS client app (let's name it aws-client) from command line, we can first set these environment variables:

export AWS_ACCESS_KEY_ID=AWS_ACCESS_KEY_ID_VALUE
export AWS_SECRET_ACCESS_KEY=AWS_SECRET_ACCESS_KEY_VALUE
export AWS_REGION=AWS_REGION_VALUE
aws-client

If aws-client is entrypoint for Docker container, we can pass these environment variables via command line:

docker run \
-e AWS_ACCESS_KEY_ID=AWS_ACCESS_KEY_ID_VALUE \
-e AWS_SECRET_ACCESS_KEY=AWS_SECRET_ACCESS_KEY_VALUE \
-e AWS_REGION=AWS_REGION_VALUE \
--rm \
aws-client-image

We can create session configuration explicitly and pass options which are programmatically set. For this, we need to:

(1) import github.com/aws/aws-sdk-go/aws package
(2) create Config structure and pass it to session constructor

sess, err := session.NewSession(&aws.Config{})

In the example above, environment variables will still be used. If we want to pass particular options, we can set matching properties of the Config structure:

// S3Region is the name of the geo region e.g. "eu-west-2"
const S3Region = "us-east-1"
...
sess, err := session.NewSession(
   &aws.Config{
      Region: aws.String(S3Region)
   }
)

For complete list of regions see Regions and Availability Zones - Amazon Relational Database Service.



TO BE CONTINUED...

2 comments:

Akanshya said...

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Sowmya said...

very informative article post. much thanks again
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