Respect .aws/credentials file + AWS_PROFILE env var as a source of auth for s3

[ahrakos]

Is your feature request related to a problem? Please describe

Currently, it's not possible to parse an .aws/credentials file if I have it mounted into the nginx-s3 container, mentioning a specific AWS_PROFILE.

Describe the solution you'd like

For local development, it's best if we would have another auth option (besides the one that exists in the awsigv4.js file), which is reading the .aws/credentials file, and extracting the keys according to a provided env AWS_PROFILE.

A clear and concise description of what you want to happen.

For local development, it's best if we would have another auth option (besides the one that exists in the awsigv4.js file), which is reading the .aws/credentials file, and extracting the keys according to a provided env AWS_PROFILE.

Describe alternatives you've considered

A clear and concise description of any alternative solutions or features you've considered.

Additional context

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