The EC2 datasource is the oldest and most widely used datasource that
cloud-init supports. This datasource interacts with a magic IP provided
to the instance by the cloud provider (typically this IP is
169.254.169.254). At this IP a http server is provided to the
instance so that the instance can make calls to get instance user data and
Metadata is accessible via the following URL:
GET http://169.254.169.254/2009-04-04/meta-data/ ami-id ami-launch-index ami-manifest-path block-device-mapping/ hostname instance-id instance-type local-hostname local-ipv4 placement/ public-hostname public-ipv4 public-keys/ reservation-id security-groups
User data is accessible via the following URL:
GET http://169.254.169.254/2009-04-04/user-data 1234,fred,reboot,true | 4512,jimbo, | 173,,,
Note that there are multiple EC2 Metadata versions of this data provided
Cloud-init attempts to use the most recent API version it
supports in order to get the latest API features and instance-data. If a given
API version is not exposed to the instance, those API features will be
unavailable to the instance.
Required for Instance tag support. This feature must be enabled individually on each instance. See the EC2 tags user guide.
Required for secondary IP address support.
Minimum supports EC2 API version for metadata and user data.
To see which versions are supported by your cloud provider use the following URL:
GET http://169.254.169.254/ 1.0 2007-01-19 2007-03-01 2007-08-29 2007-10-10 2007-12-15 2008-02-01 2008-09-01 2009-04-04 ... latest
The following configuration can be set for the datasource in system
The settings that may be configured are:
This list of URLs will be searched for an EC2 metadata service. The first
entry that successfully returns a 200 response for
<url>/<version>/meta-data/instance-id will be selected.
Default: [’http://169.254.169.254’, ‘http://[fd00:ec2::254]’, ‘http://instance-data:8773’].
The maximum amount of clock time in seconds that should be spent searching
metadata_urls. A value less than zero will result in only one request
being made, to the first in the list.
The timeout value provided to
urlopen for each individual http request.
This is used both when selecting a
metadata_url and when crawling the
Boolean (default: True) to allow
cloud-init to configure any secondary
NICs and secondary IPs described by the metadata service. All network
interfaces are configured with DHCP (v4) to obtain a primary IPv4 address and
route. Interfaces which have a non-empty
ipv6s list will also enable
DHCPv6 to obtain a primary IPv6 address and route. The DHCP response (v4 and
v6) return an IP that matches the first element of
ipv6s lists respectively. All additional values (secondary addresses) in
the static IP lists will be added to the interface.
An example configuration with the default values is provided below:
datasource: Ec2: metadata_urls: ["http://169.254.169.254:80", "http://instance-data:8773"] max_wait: 120 timeout: 50 apply_full_imds_network_config: true
There are 2 types of EC2 instances, network-wise: Virtual Private Cloud (VPC) ones and Classic ones (also known as non-VPC). One major difference between them is that Classic instances have their MAC address changed on stop/restart operations, so
cloud-initwill recreate the network config file for EC2 Classic instances every boot. On VPC instances this file is generated only on the first boot of the instance. The check for the instance type is performed by
For EC2 instances with multiple network interfaces (NICs) attached, DHCP4 will be enabled to obtain the primary private IPv4 address of those NICs. Wherever DHCP4 or DHCP6 is enabled for a NIC, a DHCP route-metric will be added with the value of
<device-number + 1> * 100to ensure DHCP routes on the primary NIC are preferred to any secondary NICs. For example: the primary NIC will have a DHCP route-metric of 100, the next NIC will have 200.