ec2-metadata 1.4.0

An easy interface to query the EC2 metadata API, with caching.

An easy interface to query the EC2 metadata API, with caching.

A quick example:

>>> from ec2_metadata import ec2_metadata
>>> print(ec2_metadata.region)
us-east-1
>>> print(ec2_metadata.instance_id)
i-123456

Installation

Use pip:

pip install ec2-metadata

Tested on Python 2.7 and Python 3.6.

Why?

boto came with a utility function to retrieve the instance metadata as a lazy loading dictionary, boto.utils.get_instance_metadata, but this has not been ported to boto3, as per this issue. I thought that rather than building a new version inside boto3 it would work well as a standalone library.

API

EC2Metadata(session=None)

A container that represents the data available on the EC2 metadata service. Attributes don’t entirely correspond to the paths in the metadata service - they have been ‘cleaned up’. You may also want to refer to the metadata service docs to understand the exact contents.

There’s a singleton instance of it at the name ec2_metadata which should cover 90% of use cases. Use it like:

from ec2_metadata import ec2_metadata
ec2_metadata.region

The session argument, if provided, should be an instance of requests.Session, allowing you to customize the way requests are made.

All the attributes cache on first access, since they are mostly immutable, or at least require an instance stop to change, however some properties like network interfaces can change over the lifetime of an instance. If you want to clear the cache of one attribute you can just del it:

del ec2_metadata.network_interfaces

To clear all, use the clear_all() method as per below.

account_id: str

The current AWS account ID, e.g. '123456789012'.

ami_id: str

The ID of the AMI used to launch the instance, e.g. 'ami-123456'.

availability_zone: str

The name of the current AZ e.g. 'eu-west-1a'.

ami_launch_index: int

The index of the instance in the launch request, zero-based, e.g. 0.

ami_manifest_path: str

The path to the AMI manifest file in Amazon S3, or '(unknown)' on EBS-backed AMI’s.

clear_all() -> None

Clear all the cached attributes on the class, meaning their next access will re-fetch the data from the metadata API.

iam_info: dict

A dictionary of data for the IAM role attached to the instance, or None if no role is attached.

instance_id: str

The current instance’s ID, e.g. 'i-123456'

instance_identity_document: dict

A dictionary of dynamic data - see AWS docs.

instance_profile_arn: str

The ARN of the IAM role/instance profile attached to the instance, taken from iam_info, or None if no role is attached.

instance_profile_id: str

The ID of the IAM role/instance profile attached to the instance, taken from iam_info, or None if no role is attached.

instance_type: str

The current instance’s type, e.g. 't2.nano'

mac : str

The instance’s MAC address, e.g. '0a:d2:ae:4d:f3:12'

network_interfaces: Dict[str, NetworkInterface]

A dictionary of mac address to NetworkInterface, which represents the data available on a network interface - see below. E.g. {'01:23:45:67:89:ab': NetworkInterface('01:23:45:67:89:ab')}

private_hostname : str

The private IPv4 DNS hostname of the instance, e.g. 'ip-172-30-0-0.eu-west-1.compute.internal' .

private_ipv4: str

The private IPv4 of the instance, e.g. '172.30.0.0'.

public_hostname : str

The public DNS hostname of the instance, or None if the instance is not public, e.g. 'ec2-1-2-3-4.compute-1.amazonaws.com'.

public_ipv4: str

The public IPv4 address of the instance, or None if the instance is not public, e.g. '1.2.3.4'.

region: str

The region the instance is running in, e.g. 'eu-west-1'.

reservation_id: str

The ID of the reservation used to launch the instance, e.g. 'r-12345678901234567'.

security_groups : List[str]

List of security groups by name, e.g. ['ssh-access', 'custom-sg-1'].

user_data: bytes

The raw user data assigned to the instance (not base64 encoded), or None if there is none.

NetworkInterface

Represents a single network interface, as retrieved from EC2Metadata.network_interfaces. Again like EC2Metadata all its attributes cache on first access, and can be cleared with del or its clear_all() method.

device_number: int

The unique device number associated with that interface, e.g. 0.

ipv4_associations: Dict[str, List[str]]

A dictionary mapping public IP addresses on the interface to the list of private IP addresses associated with that public IP, for each public IP that is associated with the interface, e.g. {'54.0.0.1': ['172.30.0.0']}.

mac: str

The MAC address of the interface, e.g. '01:23:45:67:89:ab'.

owner_id: str

The AWS Account ID of the owner of the network interface, e.g. '123456789012'.

private_hostname: str

The interface’s local/private hostname, e.g. 'ip-172-30-0-0.eu-west-1.compute.internal'.

private_ipv4s: List[str]

The private IPv4 addresses associated with the interface, e.g. ['172.30.0.0'].

public_hostname: str

The interface’s public DNS (IPv4), e.g. 'ec2-54-0-0-0.compute-1.amazonaws.com'.

public_ipv4s: List[str]

The Elastic IP addresses associated with the interface, e.g. ['54.0.0.0'].

security_groups: List[str]

The names of the security groups to which the network interface belongs, e.g. ['ssh-access', 'custom-sg-1'].

security_group_ids: List[str]

The names of the security groups to which the network interface belongs, e.g. ['sg-12345678', 'sg-12345679'].

subnet_id: str

The ID of the subnet in which the interface resides, e.g. 'subnet-12345678'.

subnet_ipv4_cidr_block: str

The IPv4 CIDR block of the subnet in which the interface resides, e.g. '172.30.0.0/24'.

vpc_id: str

The ID of the VPC in which the interface resides, e.g. 'vpc-12345678'.

vpc_ipv4_cidr_block: str

The IPv4 CIDR block of the VPC, or None if the instance isn’t in a VPC, e.g. '172.30.0.0/16'.

vpc_ipv4_cidr_blocks: List[str]

The list of IPv4 CIDR blocks, or None if the instance isn’t in a VPC, e.g. ['172.30.0.0/16'].

History

Pending Release

1.4.0 (2017-10-24)

• Add iam_info, instance_profile_arn and instance_profile_id attributes

• Refactor handling non-200 responses to be more strict for attributes where 404’s are allowed.

1.3.1 (2017-10-17)

• Fix rendering of docs on PyPI.

1.3.0 (2017-10-17)

• All methods can now raise requests.exceptions.HTTPError if the metadata API returns a bad response, rather than failing during parsing or silently returning data from non-200 responses.

• EC2Metadata can now be passed a requests.Session object for customization of the way requests are made.

1.2.1 (2017-08-31)

• Make public_* properties return None for instances that aren’t public.

1.2.0 (2017-08-26)

• Add network_interfaces attribute which is a list of NetworkInterface instances, which have many attributes themselves.

1.1.0 (2017-08-07)

• Add security_groups and user_data attributes.

1.0.0 (2017-06-16)

• First release on PyPI, featuring ec2_metadata object.