cloudbase-init/doc/source/services.rst

Services

A metadata service has the role of getting the guest provided data (configuration information) and exposing it to the plugins for a general and basic initialization of the instance. These sub-services can change their behavior according to custom configuration options documented below.

---

Configuring available services

Any of these classes can be specified manually in the configuration file under metadata_services option. Based on this option, the service loader will search across these providers in the defined order and load the first one that is available.

For more details on doing this, see configuration <config> file in tutorial.

---

OpenStack (web API)

A complete service which supports password related capabilities and can be usually accessed at the http://169.254.169.254/ magic URL. The magic URL can be customized using the metadata_base_url config option. A default value of True for add_metadata_private_ip_route option is used to add a route for the IP address to the gateway. This is needed for supplying a bridge between different VLANs in order to get access to the web server.

Metadata version used: latest.

Capabilities:

• instance id
• hostname
• public keys
• WinRM authentication certificates
• static network configuration
• admin user password
• post admin user password (only once)
• user data

Config options for openstack section:

• metadata_base_url (string: "http://169.254.169.254/")
• add_metadata_private_ip_route (bool: True)
• https_allow_insecure (bool: False)
• https_ca_bundle (string: None)

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

OpenStack (configuration drive)

This is similar to the web API, but it "serves" its files locally without requiring network access. The data is generally retrieved from a cdrom, vfat or raw disks/partitions by enabling selective lookup across different devices. Use the types option to specify which types of config drive content the service will search for and also on which devices using the locations option.

It will search for metadata:

1. in mounted optical units
2. directly in the physical disk bytes
3. by exploring the physical disk as a vfat drive; which requires mtools (specified by the mtools_path option in the Default section)

This service is usually faster than the HTTP twin, as there is no timeout waiting for the network to be up.

Metadata version used: latest.

Capabilities:

• instance id
• hostname
• public keys
• authentication certificates
• static network configuration
• admin user password
• user data

Config options for config_drive section:

• raw_hdd (bool: True)
• cdrom (bool: True)
• vfat (bool: True)
• types (list: ["vfat", "iso"])
• locations (list: ["cdrom", "hdd", "partition"])

Amazon EC2

This is similar to the OpenStack HTTP service but is using a different format for metadata endpoints and has general capabilities.

Metadata version used: 2009-04-04.

Capabilities:

• instance id
• hostname
• public keys
• user data

Config options for ec2 section:

• metadata_base_url (string: "http://169.254.169.254/")
• add_metadata_private_ip_route (bool: True)
• https_allow_insecure (bool: False)
• https_ca_bundle (string: None)

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

Note

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/ec2-instance-metadata.html

Apache CloudStack

Another web-based service which usually uses "10.1.1.1" or DHCP addresses for retrieving content. If no metadata can be found at the metadata_base_url, the service will look for the metadata at the DHCP server URL.

Capabilities:

• instance id
• hostname
• public keys
• admin user password
• poll for, post, delete admin user password (each reboot)
• user data

Config options for cloudstack section:

• metadata_base_url (string: "http://10.1.1.1/")
• password_server_port (int: 8080)
• add_metadata_private_ip_route (bool: True)
• https_allow_insecure (bool: False)
• https_ca_bundle (string: None)

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

Note

By design, this service can update the password anytime, so it will cause the setuserpassword plugin to run at every boot and by security concerns, the password is deleted right after retrieval and no updating will occur until a new password is available on the server.

OpenNebula Service

The OpenNebula provider is related to configuration drive and searches for a specific context file which holds all the available info. The provided details are exposed as bash variables gathered in a shell script.

Capabilities:

• hardcoded instance id to iid-dsopennebula
• hostname
• public keys
• static network configuration
• user data

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

Ubuntu MaaS

This metadata service usually works with instances on baremetal and uses web requests for retrieving the available exposed metadata. It uses OAuth to secure the requests.

Metadata version used: 2012-03-01.

Capabilities:

• instance id
• hostname
• public keys
• WinRM authentication certificates
• static network configuration
• user data

Config options for maas section:

• metadata_base_url (string: None)
• oauth_consumer_key (string: None)
• oauth_consumer_secret (string: None)
• oauth_token_key (string: None)
• oauth_token_secret (string: None)
• https_allow_insecure (bool: False)
• https_ca_bundle (string: None)

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

Note

By design, the configuration options are set by an agent called curtin which runs the hooks that set the config values. On Windows, these hooks need to be present in the root directory: Windows curtin hooks.

Open Virtualization Format (OVF)

The OVF provider searches data from OVF environment ISO transport.

Capabilities:

• instance id (hardcoded to iid-ovf if not present)
• hostname
• public keys
• admin user name
• admin user password
• user data

Config options:

• config_file_name (string: "ovf-env.xml")
• drive_label (string: "OVF ENV")
• ns (string: "oe")

Packet Service

Packet metadata service provides the metadata for baremetal servers at the magic URL https://metadata.packet.net/.

Capabilities:

• instance id
• hostname
• public keys
• user data

Config options for packet section:

• metadata_base_url (string: "https://metadata.packet.net/")
• https_allow_insecure (bool: False)
• https_ca_bundle (string: None)

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)

Azure Service

Azure metadata service provides the metadata for Microsoft Azure cloud platform.

Azure metadata is offered via multiple sources like HTTP metadata, config-drive metadata and KVP (Hyper-V Key-Value Pair Data Exchange). This implementation uses only HTTP and config-drive metadata sources.

Azure service implements the interface to notify the cloud provider when the instance has started provisioning, completed provisioning and if the provisioning failed.

Metadata version used: 2015-04-05.

Capabilities:

• instance id
• hostname
• public keys
• WinRM authentication certificates
• admin user name
• admin user password
• user data
• post RDP certificate thumbprint
• provisioning status
• Windows Update status
• VM agent configuration
• licensing configuration
• ephemeral disk warning

Config options for azure section:

• transport_cert_store_name (string: Windows Azure Environment")

Config options for default section:

• retry_count (integer: 5)
• retry_count_interval (integer: 4)