AWS Instance Metadata Service (IMDS)

Wikipedia:AWS Instance Metadata Service it is a service provided by AWS that allows EC2 instances to access metadata about themselves and their environment.

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

• aws ec2 modify-instance-metadata-options
• IMDS versions: IMDSv2
• IMDS initiate session

If you use Auto Scaling groups and you need to require the use of IMDSv2 on all new instances, your Auto Scaling groups must use launch templates.

• Datadog AWS Integration Billing: If your EC2 instances are configured to require the use of Instance Metadata Service Version 2 (IMDSv2), then you must set the parameter ec2_prefer_imdsv2 to true in your Datadog agent configuration to avoid double-billing.

Metadata Endpoint

http://169.254.169.254/latest/meta-data/

Example

 TOKEN=`curl -X PUT "http://169.254.169.254/latest/api/token" -H "X-aws-ec2-metadata-token-ttl-seconds: 21600"` \ && curl -H "X-aws-ec2-metadata-token: $TOKEN" -v http://169.254.169.254/latest/user-data

Activities

• Transition to using Instance Metadata Service Version 2

Related

• Azure Instance Metadata Service
• ec2-imdsv2-check, the rule is NON_COMPLIANT if the HttpTokens is set to optional.
• aws ec2 describe-instances | grep HttpTokens
• AWS EC2 Instance Connect
• Datadog: DD_EC2_PREFER_IMDSV2
• Datadog: EC2 instances should enforce IMDSv2
• IMDS initiate session
• Failed to refresh cached credentials, no EC2 IMDS role found

See also

• IMDS
• IMDS, IMDS versions (IMDSv2), IMDS initiate session, ec2-imdsv2-check, aws ec2 modify-instance-metadata-options, /latest/meta-data, /latest/user-data, modify-instance-metadata-defaults
• AWS EC2, Amazon EC2 API, aws ec2, AWS::EC2, Amazon EC2 Spot Instances, CPU credits, Instance type, EC2 limitations, 169.254.169.254, Instance metadata and user data (IMDS), InstanceType, InstanceId, Amazon EC2 Auto Scaling, AWS EC2 Instance Connect, launch template, lifecycle, AWS Security group (SG), Amazon EC2 Recycle Bin, Amazon EC2 Mac Instances, Global View