============ ec2-metadata

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An easy interface to query the EC2 metadata API (version 2), with caching.

A quick example:

.. code-block:: pycon

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

Working on a Django project? Improve your skills with one of my books <https://adamj.eu/books/>__.

Installation

Use pip:

.. code-block:: sh

python -m pip install ec2-metadata

Python 3.8 to 3.12 supported.

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 <https://github.com/boto/boto3/issues/313>_. I thought that rather than building a new version inside boto3 it would work well as a standalone library.

Instance Metadata Service Version 2

In November 2019, AWS released version 2 <https://aws.amazon.com/blogs/security/defense-in-depth-open-firewalls-reverse-proxies-ssrf-vulnerabilities-ec2-instance-metadata-service/>__ of the instance metadata service. It's more secure against Server Side Request Forgery (SSRF) attacks.

ec2-metadata now uses it exclusively. You can therefore consider disabling version 1, as per AWS' guide <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/configuring-instance-metadata-service.html#instance-metadata-transition-to-version-2>__.

Note: Instance Metadata Service v2 has a default IP hop limit of 1. This can mean that you can see requests.exceptions.ReadTimeout errors from within Docker containers. To solve this, reconfigure your EC2 instance’s metadata options to allow three hops with |aws ec2 modify-instance-metadata-options|__:

.. |aws ec2 modify-instance-metadata-options| replace:: aws ec2 modify-instance-metadata-options __ https://docs.aws.amazon.com/cli/latest/reference/ec2/modify-instance-metadata-options.html

.. code-block:: bash

aws ec2 modify-instance-metadata-options  --instance-id <instance-id> --http-put-response-hop-limit 3

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 <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-categories.html>_ 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:

.. code-block:: python

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.

Most of the attributes are cached, except where noted below. This is because they are mostly immutable, or at least require an instance stop to change. However some cached attributes do represent things that can change without an instance stop, but rarely do, such as network devices.

The caching is done with @cached_property, so they cache on first access. If you want to clear the cache of one attribute you can just del it:

.. code-block:: python

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'``.

``autoscaling_target_lifecycle_state: str | None``

Uncached. The target Auto Scaling lifecycle state that the instance is transitionioning to, or None if the instance is not in an autoscaling group. See AWS docs page Retrieve the target lifecycle state through instance metadata <https://docs.aws.amazon.com/autoscaling/ec2/userguide/retrieving-target-lifecycle-state-through-imds.html>__.

availability_zone: str

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

``availability_zone_id: str | None``

The unique, cross-account ID of the current AZ e.g. 'use1-az6'. See AWS docs page AZ IDs for your AWS resources <https://docs.aws.amazon.com/ram/latest/userguide/working-with-az-ids.html>__.

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. This includes clearing the token used
to authenticate with the service.

``domain: str``
~~~~~~~~~~~~~~~

The domain for AWS resources for the region. E.g. ``'amazonaws.com'`` for the
standard AWS regions and GovCloud (US), or ``'amazonaws.com.cn'`` for China.

``iam_info: IamInfoDict | None``

A dictionary of data for the IAM role attached to the instance, or None if no role is attached. The dict has this type, based on what the metadata service returns:

.. code-block:: python

class IamInfoDict(TypedDict):
    InstanceProfileArn: str
    InstanceProfileId: str
    LastUpdated: str

iam_security_credentials: IamSecurityCredentialsDict | None

A dictionary of data for the security credentials associated with the IAM role attached to the instance, or ``None`` if no role is attached.
See the `AWS docs section “Retrieve security credentials from instance metadata” <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/iam-roles-for-amazon-ec2.html#instance-metadata-security-credentials>`__
for details.
The dict has this type, based on that document:

.. code-block:: python

    class IamSecurityCredentialsDict(TypedDict):
        LastUpdated: str
        Type: str
        AccessKeyId: str
        SecretAccessKey: str
        Token: str
        Expiration: str

``instance_action: str``
~~~~~~~~~~~~~~~~~~~~~~~~

**Uncached.**
A state that notifies if the instance will reboot in preparation
for bundling. See the `AWS docs section “Instance Metadata Categories”
<https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-data-categories.html>`_
for the valid values.

``instance_id: str``
~~~~~~~~~~~~~~~~~~~~

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

``instance_identity_document: InstanceIdentityDocumentDict``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

A dictionary of dynamic data about the instance.
See the `AWS docs page “Instance Identity Documents” <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instance-identity-documents.html>`__ for an explanation of the contents.
The dict has this type, based on that document:

.. code-block:: python

    class InstanceIdentityDocumentDict(TypedDict):
        accountId: str
        architecture: Literal["i386", "x86_64", "arm64"]
        availabilityZone: str
        billingProducts: list[str] | None
        marketplaceProductCodes: list[str] | None
        imageId: str
        instanceId: str
        instanceType: str
        kernelId: str | None
        pendingTime: str
        privateIp: str
        ramdiskId: str | None
        region: str
        version: str

``instance_profile_arn: str | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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


``instance_profile_name: str | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The instance profile name, extracted from ``instance_profile_arn``, or ``None`` if no role is attached.

``instance_type: str``
~~~~~~~~~~~~~~~~~~~~~~

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

``kernel_id: str | None``
~~~~~~~~~~~~~~~~~~~~~~~~~

The current instance's kernel ID, or ``None`` if it doesn't have one, e.g.
``'aki-dc9ed9af'``.

``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')}``

``partition: str``
~~~~~~~~~~~~~~~~~~

The AWS partition where the instance is running. E.g. ``'aws'`` for the
standard AWS regions, ``'aws-us-gov'`` for GovCloud (US), or ``'aws-cn'``
for China.

``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 | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~

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']``.

``spot_instance_action: SpotInstanceAction | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

**Uncached.**
An object describing an action about to happen to this spot instance.
Returns ``None`` if the instance is not spot, or not marked for termination.

The ``SpotInstanceAction`` object has two attributes:

* ``action: str`` - the action about to happen, one of ``"hibernate"``, ``"stop"``, or ``"terminate"``.
* ``time: datetime`` - the approximate UTC datetime when the action will occur.

See `AWS docs section <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/spot-instance-termination-notices.html#instance-action-metadata>`__ for a little more information.

``tags: InstanceTags``
~~~~~~~~~~~~~~~~~~~~~~

A dict-like mapping of the tags for the instance (documented below).
This requires you to `explicitly enable the feature <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#allow-access-to-tags-in-IMDS>`__ for the instance.
If the feature is not enabled, accessing this attribute raises an error.

(It also seems that there is a bug where if the feature is enabled and then disabled, the metadata service returns an empty response.
This is indistinguishable from “no tags”, so beware that in that case, ``InstanceTags`` will just look like an empty mapping.)

``user_data: bytes | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~

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

``InstanceTags``
----------------

A dict-like mapping of tag names to values (both ``str``\s).
To avoid unnecessary requests, the mapping is lazy: values are only fetched when required.
(Names are known on construction though, from the first request in ``EC2Metadata.tags``.)

The metadata service will receive tag updates on some instance types, as per `the AWS documentation <https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/Using_Tags.html#work-with-tags-in-IMDS>`__:

    If you add or remove an instance tag, the instance metadata is updated while the instance is running for instances built on the Nitro System, without needing to stop and then start the instance.
    For all other instances, to update the tags in the instance metadata, you must stop and then start the instance.

Because ``InstanceTags`` is cached, it won’t reflect such updates on Nitro instances unless you clear it first:

.. code-block:: python

    del ec2_metadata.tags
    ec2_metadata.tags["Name"]  # fresh

``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``.

``interface_id: str``
~~~~~~~~~~~~~~~~~~~~~

The unique id used to identify the Elastic Network Interface, e.g. ``'eni-12345'``.

``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']}``.

``ipv6s: list[str]``
~~~~~~~~~~~~~~~~~~~~

The IPv6 addresses associated with the interface, e.g.
``['2001:db8:abcd:ef00::1234']``.

``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 | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The IPv4 CIDR block of the subnet in which the interface resides, or ``None``
if there is none, e.g. ``'172.30.0.0/24'``.

``subnet_ipv6_cidr_blocks: list[str]``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The list of IPv6 CIDR blocks of the subnet in which the interface resides, e.g.
``['2001:db8:abcd:ef00::/64']``. If the subnet does not have any IPv6 CIDR
blocks or the instance isn't in a VPC, the list will be empty, e.g. ``[]``.

``vpc_id: str``
~~~~~~~~~~~~~~~

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

``vpc_ipv4_cidr_block: str | None``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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 e.g. ``['172.30.0.0/16']``. If the interface
doesn’t have any such CIDR blocks, the list will be empty.

``vpc_ipv6_cidr_blocks: list[str]``
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The list of IPv6 CIDR blocks of the VPC in which the interface resides, e.g.
``['2001:db8:abcd:ef00::/56']``. If the VPC does not have any IPv6 CIDR blocks
or the instance isn't in a VPC, the list will be empty, e.g. ``[]``.