Metadata service compatible with imdsv2

[BenCodeOcean]

imdsv2 is a required security standard. To achieve imdsv2 compatibility, it is required to change the entire metadata service requests by adding a header with a token.
This fix is necessary since the EBS Autoscale service failed on an EC2 instance with a configured option of a required http-tokens:

aws ec2 modify-instance-metadata-options \
    --instance-id i-1234567898abcdef0 \
    --http-tokens required

Source: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-options.html

Description of changes:
The get_metadata function changed and a request for a token was added before the metadata request itself. Also, all the metadata service requests are sent using the get_metadata function.

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[wleepang]

This looks reasonable. However, using IMDSv2 is currently optional and not all AMIs may be configured to use it according to the docs.

Can this be a configuration parameter that users can opt-in as needed?

[BenCodeOcean]

Yes, configuration parameter will be a fit solution.
I added an optional flag for imdsv2 enabling:

    -i, --imdsv2        
                        Enable imdsv2 for instance metadata API requests.