IMDS.
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AWS EC2 Instance Metadata Service, version 2 (IMDSv2).
The provider asks for a session token with PUT /latest/api/token and sends
the token in the x-aws-ec2-metadata-token header of the metadata requests
of one operation. A request that answers with HTTP 401 asks for a new token
one time.
IMDSv1 is used when the token request answers with HTTP 403, 404 or 405 and
the :aws_imds_v1_fallback option is not false. The fallback is enabled
by default.
The region comes from /latest/dynamic/instance-identity/document when that
document is available. The fallback derives the region from the availability
zone, including local zones such as us-west-2-lax-1a and partitions such as
us-iso-east-1a. A failed document request other than HTTP 404 does not
start the fallback: a timeout stays a timeout.
The identity document also gives the instance type and the account ID, which
the identity map returns as instance_type and scope_id. The fallback
reads the instance type from /latest/meta-data/instance-type and leaves
scope_id empty.
Summary
Functions
Derive the region from an availability zone name.
Functions
Derive the region from an availability zone name.
The identity document has an authoritative region. Use this function only when that document does not give the region.
Examples
iex> IMDS.Providers.AWS.region_from_zone("us-west-2a")
"us-west-2"
iex> IMDS.Providers.AWS.region_from_zone("us-west-2-lax-1a")
"us-west-2"
iex> IMDS.Providers.AWS.region_from_zone("us-iso-east-1a")
"us-iso-east-1"
iex> IMDS.Providers.AWS.region_from_zone(nil)
nil