nova/api-ref/source/servers.rst

Servers (servers)

Lists, creates, shows details for, updates, and deletes servers.

Concepts

Passwords

When you create a server, you can specify a password through the optional adminPass attribute. The password must meet the complexity requirements set by your OpenStack Compute provider. The server might enter an ERROR state if the complexity requirements are not met. In this case, a client might issue a change password action to reset the server password.

If you do not specify a password, the API generates and assigns a random password that it returns in the response object. This password meets the security requirements set by the compute provider. For security reasons, subsequent GET calls do not require this password.

Server metadata

You can specify custom server metadata at server launch time. The maximum size for each metadata key-value pair is 255 bytes. The compute provider determines the maximum number of key-value pairs for each server. You can query this value through the maxServerMeta absolute limit.

Server networks

You can specify one or more networks to which the server connects at launch time. Users can also specify a specific port on the network or the fixed IP address to assign to the server interface.

You can use both IPv4 and IPv6 addresses as access addresses and you can assign both addresses simultaneously. You can update access addresses after you create a server.

Server personality

To customize the personality of a server instance, you can inject data into its file system. For example, you might insert ssh keys, set configuration files, or store data that you want to retrieve from inside the instance. This customization method provides minimal launch-time personalization. If you require significant customization, create a custom image.

Follow these guidelines when you inject files:

The maximum size of the file path data is 255 bytes.

Encode the file contents as a Base64 string. The compute provider determines the maximum size of the file contents. The image that you use to create the server determines this value.

The maximum limit refers to the number of bytes in the decoded data and not to the number of characters in the encoded data.

The maxPersonality absolute limit defines the maximum number of file path and content pairs that you can supply. The compute provider determines this value.

The maxPersonalitySize absolute limit is a byte limit that applies to all images in the deployment. Providers can set additional per-image personality limits.

The file injection might not occur until after the server builds and boots.

After file injection, only system administrators can access personality files. For example, on Linux, all files have root as the owner and the root group as the group owner, and allow only user and group read access (chmod 440).

Server access addresses

In a hybrid environment, the underlying implementation might not control the IP address of a server. Instead, the access IP address might be part of the dedicated hardware; for example, a router/NAT device. In this case, you cannot use the addresses that the implementation provides to access the server from outside the local LAN. Instead, the API might assign a separate access address at creation time to provide access to the server. This address might not be directly bound to a network interface on the server and might not necessarily appear when you query the server addresses. However, clients should use an access address to access the server directly.

List servers - Lists IDs, names, and links for all servers.

Servers contain a status attribute that indicates the current server state. You can filter on the server status when you complete a list servers request. The server status is returned in the response body. The possible server status values are:

• ACTIVE. The server is active.
• BUILDING. The server has not finished the original build process.
• DELETED. The server is permanently deleted.
• ERROR. The server is in error.
• HARD_REBOOT. The server is hard rebooting. This is equivalent to pulling the power plug on a physical server, plugging it back in, and rebooting it.
• MIGRATING. The server is being migrated to a new host.
• PASSWORD. The password is being reset on the server.
• PAUSED. In a paused state, the state of the server is stored in RAM. A paused server continues to run in frozen state.
• REBOOT. The server is in a soft reboot state. A reboot command was passed to the operating system.
• REBUILD. The server is currently being rebuilt from an image.
• RESCUED. The server is in rescue mode. A rescue image is running with the original server image attached.
• RESIZED. Server is performing the differential copy of data that changed during its initial copy. Server is down for this stage.
• REVERT_RESIZE. The resize or migration of a server failed for some reason. The destination server is being cleaned up and the original source server is restarting.
• SOFT_DELETED. The server is marked as deleted but the disk images are still available to restore.
• STOPPED. The server is powered off and the disk image still persists.
• SUSPENDED. The server is suspended, either by request or necessity. This status appears for only the XenServer/XCP, KVM, and ESXi hypervisors. Administrative users can suspend an instance if it is infrequently used or to perform system maintenance. When you suspend an instance, its VM state is stored on disk, all memory is written to disk, and the virtual machine is stopped. Suspending an instance is similar to placing a device in hibernation; memory and vCPUs become available to create other instances.
• UNKNOWN. The state of the server is unknown. Contact your cloud provider.
• VERIFY_RESIZE. System is awaiting confirmation that the server is operational after a move or resize.

Normal response codes: 200

Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405)

Request parameters

• tenant_id: tenant_id
• changes-since: changes-since
• image: image
• flavor: flavor
• name: name
• status: status
• host: host
• limit: limit
• marker: marker

Response Example

/../../doc/api_samples/servers/servers-list-resp.json

Response Parameters

• x-openstack-request-id: request_id
• servers: servers
• id: server_id
• links: generic_links
• name: server_name

Create server

The progress of this operation depends on the location of the requested image, network I/O, host load, selected flavor, and other factors.

To check the progress of the request, make a GET /servers/{id} request. This call returns a progress attribute, which is a percentage value from 0 to 100.

The Location header returns the full URL to the newly created server and is available as a self and bookmark link in the server representation.

When you create a server, the response shows only the server ID, its links, and the admin password. You can get additional attributes through subsequent GET requests on the server.

Include the block-device-mapping-v2 parameter in the create request body to boot a server from a volume.

Include the key_name parameter in the create request body to add a keypair to the server when you create it. To create a keypair, make a create keypair request.

Preconditions

The user must have sufficient server quota to create the number of servers requested.

The connection to the Image service is valid.

Asynchronous postconditions

With correct permissions, you can see the server status as ACTIVE through API calls.

With correct access, you can see the created server in the compute node that OpenStack Compute manages.

Troubleshooting

If the server status remains BUILDING or shows another error status, the request failed. Ensure you meet the preconditions then investigate the compute node.

The server is not created in the compute node that OpenStack Compute manages.

The compute node needs enough free resource to match the resource of the server creation request.

Ensure that the scheduler selection filter can fulfill the request with the available compute nodes that match the selection criteria of the filter.

Normal response codes: 202

Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405), itemNotFound (404)

Request Example

/../../doc/api_samples/servers/server-create-req.json

Request Parameters

• tenant_id: tenant_id
• server: server
• security_groups: security_groups
• user_data: user_data
• os-availability-zone:availability_zone: availability_zone
• imageRef: image_ref
• flavorRef: flavor_ref
• networks: network_obj
• name: server_name
• fixed_ip: fixed_ip
• metadata: metadata
• personality: personality
• block_device_mapping_v2: block_device_mapping_v2
• device_name: bdm_device_name
• source_type: bdm_source_type
• destination_type: bdm_destination_type
• delete_on_termination: bdm_delete_on_termination
• guest_format: bdm_guest_format
• boot_index: bdm_boot_index
• config_drive: config_drive
• key_name: keypair_name
• os:scheduler_hints: scheduler_hints
• OS-DCF:diskConfig: server_disk_config

Response Example

/../../doc/api_samples/servers/server-create-resp.json

Response Parameters

• x-openstack-request-id: request_id
• server: server
• adminPass: admin_pass
• name: server_name
• security_groups: security_groups
• id: server_id
• links: generic_links

List Servers Detailed

The compute provisioning algorithm has an anti-affinity property that attempts to spread customer VMs across hosts. Under certain situations, VMs from the same customer might be placed on the same host. The hostId property shows the host that your server runs on and can be used to determine this scenario if it is relevant to your application.

For each server, shows server details including configuration drive, extended status, and server usage information.

The extended status information appears in the OS-EXT-STS:vm_state, OS-EXT-STS:power_state, and OS-EXT-STS:task_state attributes.

The server usage information appears in the OS-SRV-USG:launched_at and OS-SRV-USG:terminated_at attributes.

To hide addresses information for instances in a certain state, set the osapi_hide_server_address_states configuration option. Set this option to a valid VM state in the nova.conf configuration file.

HostId is unique per account and is not globally unique.

Normal response codes: 200

Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405)

Request Parameters

• tenant_id: tenant_id
• changes-since: changes-since
• image: image
• flavor: flavor
• name: name
• status: status
• host: host
• limit: limit
• marker: marker

Response Parameters

• servers: servers
• addresses: server_addresses
• created: created
• flavor: flavor_obj
• hostId: hostId
• id: server_id
• image: image_obj
• key_name: keypair_name
• links: generic_links
• metadata: metadata
• name: server_name
• OS-DCF:diskConfig: server_disk_config
• OS-EXT-AZ:availability_zone: availability_zone
• OS-EXT-SRV-ATTR:host: server_compute_hostname
• OS-EXT-SRV-ATTR:hypervisor_hostname: server_hypervisor_hostname
• OS-EXT-SRV-ATTR:instance_name: server_instance_name
• OS-EXT-STS:power_state: server_power_state
• OS-EXT-STS:task_state: server_task_state
• OS-EXT-STS:vm_state: server_vm_state
• os-extended-volumes:volumes_attached: server_volumes_attached
• OS-SRV-USG:launched_at: server_launched_at
• OS-SRV-USG:terminated_at: server_terminated_at
• progress: build_progress
• security_groups: security_groups_obj
• description: sg_description
• id: sg_id
• name: sg_name
• rules: sg_rules
• status: server_status
• tenant_id: tenant_id_body
• updated: updated
• user_id: user_id
• locked: server_locked
• host_status: host_status
• description: server_description

Example Response

/../../doc/api_samples/servers/servers-details-resp.json

Show Server Details

Includes server details including configuration drive, extended status, and server usage information.

The extended status information appears in the OS-EXT-STS:vm_state, OS-EXT-STS:power_state, and OS-EXT-STS:task_state attributes.

The server usage information appears in the OS-SRV-USG:launched_at and OS-SRV-USG:terminated_at attributes.

To hide addresses information for instances in a certain state, set the osapi_hide_server_address_states configuration option. Set this option to a valid VM state in the nova.conf configuration file.

HostId is unique per account and is not globally unique.

Preconditions

The server must exist.

Normal response codes: 200

Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405), itemNotFound (404)

Request Parameters

• tenant_id: tenant_id
• server_id: server_id_url

Response Parameters

• servers: servers
• addresses: server_addresses
• created: created
• flavor: flavor_obj
• hostId: hostId
• id: server_id
• image: image_obj
• key_name: keypair_name
• links: generic_links
• metadata: metadata
• name: server_name
• OS-DCF:diskConfig: server_disk_config
• OS-EXT-AZ:availability_zone: availability_zone
• OS-EXT-SRV-ATTR:host: server_compute_hostname
• OS-EXT-SRV-ATTR:hypervisor_hostname: server_hypervisor_hostname
• OS-EXT-SRV-ATTR:instance_name: server_instance_name
• OS-EXT-STS:power_state: server_power_state
• OS-EXT-STS:task_state: server_task_state
• OS-EXT-STS:vm_state: server_vm_state
• os-extended-volumes:volumes_attached: server_volumes_attached
• OS-SRV-USG:launched_at: server_launched_at
• OS-SRV-USG:terminated_at: server_terminated_at
• progress: build_progress
• security_groups: security_groups_obj
• description: sg_description
• id: sg_id
• name: sg_name
• rules: sg_rules
• status: server_status
• tenant_id: tenant_id_body
• updated: updated
• user_id: user_id
• locked: server_locked
• host_status: host_status
• description: server_description

Example Response

/../../doc/api_samples/servers/server-get-resp.json

Update Server

Preconditions

The server must exist.

You can edit the accessIPv4, accessIPv6, diskConfig and name attributes.

Normal response codes: 200 Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405), itemNotFound (404), buildInProgress (409)

Request Parameters

(NOTE: sdague) - the upstream docs here are completely scatted and seem to include the create parameters in this list when most of them don't work.

• tenant_id: tenant_id
• server_id: server_id_url
• description: server_description

Response Parameters

• servers: servers
• addresses: server_addresses
• created: created
• flavor: flavor_obj
• hostId: hostId
• id: server_id
• image: image_obj
• key_name: keypair_name
• links: generic_links
• metadata: metadata
• name: server_name
• OS-DCF:diskConfig: server_disk_config
• OS-EXT-AZ:availability_zone: availability_zone
• OS-EXT-SRV-ATTR:host: server_compute_hostname
• OS-EXT-SRV-ATTR:hypervisor_hostname: server_hypervisor_hostname
• OS-EXT-SRV-ATTR:instance_name: server_instance_name
• OS-EXT-STS:power_state: server_power_state
• OS-EXT-STS:task_state: server_task_state
• OS-EXT-STS:vm_state: server_vm_state
• os-extended-volumes:volumes_attached: server_volumes_attached
• OS-SRV-USG:launched_at: server_launched_at
• OS-SRV-USG:terminated_at: server_terminated_at
• progress: build_progress
• security_groups: security_groups_obj
• description: sg_description
• id: sg_id
• name: sg_name
• rules: sg_rules
• status: server_status
• tenant_id: tenant_id_body
• updated: updated
• user_id: user_id
• locked: server_locked
• host_status: host_status
• description: server_description

Example Requests

Updating the allowed fields for a server

/../../doc/api_samples/servers/server-update-req.json

Example Response

/../../doc/api_samples/servers/server-update-resp.json

Delete Server

Preconditions

• The server must exist.
• Anyone can delete a server when the status of the server is not locked and when the policy allows.
• If the server is locked, you must have administrator privileges to delete the server.

Asynchronous postconditions

• With correct permissions, you can see the server status as DELETED through API calls.
• The port attached to the server is deleted.
• The server does not appear in the list servers response.
• The server managed by OpenStack Compute is deleted on the compute node.

Troubleshooting

• If server status remains in deleting status or another error status, the request failed. Ensure that you meet the preconditions. Then, investigate the compute back end.
• The request returns the HTTP 409 response code when the server is locked even if you have correct permissions. Ensure that you meet the preconditions then investigate the server status.
• The server managed by OpenStack Compute is not deleted from the compute node.

Normal response codes: 204 Error response codes: computeFault (400, 500, …), serviceUnavailable (503), badRequest (400), unauthorized (401), forbidden (403), badMethod (405), itemNotFound (404)

Request Parameters

• tenant_id: tenant_id
• server_id: server_id_url