REST API Version History ~~~~~~~~~~~~~~~~~~~~~~~~ This documents the changes made to the REST API with every microversion change. The description for each version should be a verbose one which has enough information to be suitable for use in user documentation. .. _1.0 (Maximum in Newton): 1.0 Initial Version (Maximum in Newton) --------------------------------------- .. versionadded:: Newton This is the initial version of the placement REST API that was released in Nova 14.0.0 (Newton). This contains the following routes: * ``/resource_providers`` * ``/resource_providers/allocations`` * ``/resource_providers/inventories`` * ``/resource_providers/usages`` * ``/allocations`` 1.1 Resource provider aggregates -------------------------------- .. versionadded:: Ocata The 1.1 version adds support for associating aggregates with resource providers. The following new operations are added: ``GET /resource_providers/{uuid}/aggregates`` Return all aggregates associated with a resource provider ``PUT /resource_providers/{uuid}/aggregates`` Update the aggregates associated with a resource provider 1.2 Add custom resource classes ------------------------------- .. versionadded:: Ocata Placement API version 1.2 adds basic operations allowing an admin to create, list and delete custom resource classes. The following new routes are added: ``GET /resource_classes`` Return all resource classes ``POST /resource_classes`` Create a new custom resource class ``PUT /resource_classes/{name}`` Update the name of a custom resource class ``DELETE /resource_classes/{name}`` Delete a custom resource class ``GET /resource_classes/{name}`` Get a single resource class Custom resource classes must begin with the prefix ``CUSTOM_`` and contain only the letters A through Z, the numbers 0 through 9 and the underscore ``_`` character. 1.3 member_of query parameter ----------------------------- .. versionadded:: Ocata Version 1.3 adds support for listing resource providers that are members of any of the list of aggregates provided using a ``member_of`` query parameter:: ?member_of=in:{agg1_uuid},{agg2_uuid},{agg3_uuid} 1.4 Filter resource providers by requested resource capacity (Maximum in Ocata) ------------------------------------------------------------------------------- .. versionadded:: Ocata The 1.4 version adds support for querying resource providers that have the ability to serve a requested set of resources. A new "resources" query string parameter is now accepted to the ``GET /resource_providers`` API call. This parameter indicates the requested amounts of various resources that a provider must have the capacity to serve. The "resources" query string parameter takes the form:: ?resources=$RESOURCE_CLASS_NAME:$AMOUNT,$RESOURCE_CLASS_NAME:$AMOUNT For instance, if the user wishes to see resource providers that can service a request for 2 vCPUs, 1024 MB of RAM and 50 GB of disk space, the user can issue a request to:: GET /resource_providers?resources=VCPU:2,MEMORY_MB:1024,DISK_GB:50 If the resource class does not exist, then it will return a HTTP 400. .. note:: The resources filtering is also based on the `min_unit`, `max_unit` and `step_size` of the inventory record. For example, if the `max_unit` is 512 for the DISK_GB inventory for a particular resource provider and a GET request is made for `DISK_GB:1024`, that resource provider will not be returned. The `min_unit` is the minimum amount of resource that can be requested for a given inventory and resource provider. The `step_size` is the increment of resource that can be requested for a given resource on a given provider. 1.5 DELETE all inventory for a resource provider ------------------------------------------------ .. versionadded:: Pike Placement API version 1.5 adds DELETE method for deleting all inventory for a resource provider. The following new method is supported: ``DELETE /resource_providers/{uuid}/inventories`` Delete all inventories for a given resource provider 1.6 Traits API -------------- .. versionadded:: Pike The 1.6 version adds basic operations allowing an admin to create, list, and delete custom traits, also adds basic operations allowing an admin to attach traits to a resource provider. The following new routes are added: ``GET /traits`` Return all resource classes. ``PUT /traits/{name}`` Insert a single custom trait. ``GET /traits/{name}`` Check if a trait name exists. ``DELETE /traits/{name}`` Delete the specified trait. ``GET /resource_providers/{uuid}/traits`` Return all traits associated with a specific resource provider. ``PUT /resource_providers/{uuid}/traits`` Update all traits for a specific resource provider. ``DELETE /resource_providers/{uuid}/traits`` Remove any existing trait associations for a specific resource provider Custom traits must begin with the prefix ``CUSTOM_`` and contain only the letters A through Z, the numbers 0 through 9 and the underscore ``_`` character. 1.7 Idempotent PUT /resource_classes/{name} ------------------------------------------- .. versionadded:: Pike The 1.7 version changes handling of ``PUT /resource_classes/{name}`` to be a create or verification of the resource class with ``{name}``. If the resource class is a custom resource class and does not already exist it will be created and a ``201`` response code returned. If the class already exists the response code will be ``204``. This makes it possible to check or create a resource class in one request. 1.8 Require placement 'project_id', 'user_id' in PUT /allocations ----------------------------------------------------------------- .. versionadded:: Pike The 1.8 version adds ``project_id`` and ``user_id`` required request parameters to ``PUT /allocations``. 1.9 Add GET /usages -------------------- .. versionadded:: Pike The 1.9 version adds usages that can be queried by a project or project/user. The following new routes are added: ``GET /usages?project_id=`` Return all usages for a given project. ``GET /usages?project_id=&user_id=`` Return all usages for a given project and user. 1.10 Allocation candidates (Maximum in Pike) -------------------------------------------- .. versionadded:: Pike The 1.10 version brings a new REST resource endpoint for getting a list of allocation candidates. Allocation candidates are collections of possible allocations against resource providers that can satisfy a particular request for resources. 1.11 Add 'allocations' link to the ``GET /resource_providers`` response ----------------------------------------------------------------------- .. versionadded:: Queens The ``/resource_providers/{rp_uuid}/allocations`` endpoint has been available since version 1.0, but was not listed in the ``links`` section of the ``GET /resource_providers`` response. The link is included as of version 1.11. 1.12 PUT dict format to /allocations/{consumer_uuid} ---------------------------------------------------- .. versionadded:: Queens In version 1.12 the request body of a ``PUT /allocations/{consumer_uuid}`` is expected to have an ``object`` for the ``allocations`` property, not as ``array`` as with earlier microversions. This puts the request body more in alignment with the structure of the ``GET /allocations/{consumer_uuid}`` response body. Because the ``PUT`` request requires ``user_id`` and ``project_id`` in the request body, these fields are added to the ``GET`` response. In addition, the response body for ``GET /allocation_candidates`` is updated so the allocations in the ``alocation_requests`` object work with the new ``PUT`` format. 1.13 POST multiple allocations to /allocations ---------------------------------------------- .. versionadded:: Queens Version 1.13 gives the ability to set or clear allocations for more than one consumer UUID with a request to ``POST /allocations``. 1.14 Add nested resource providers ---------------------------------- .. versionadded:: Queens The 1.14 version introduces the concept of nested resource providers. The resource provider resource now contains two new attributes: * ``parent_provider_uuid`` indicates the provider's direct parent, or null if there is no parent. This attribute can be set in the call to ``POST /resource_providers`` and ``PUT /resource_providers/{uuid}`` if the attribute has not already been set to a non-NULL value (i.e. we do not support "reparenting" a provider) * ``root_provider_uuid`` indicates the UUID of the root resource provider in the provider's tree. This is a read-only attribute A new ``in_tree=`` parameter is now available in the ``GET /resource-providers`` API call. Supplying a UUID value for the ``in_tree`` parameter will cause all resource providers within the "provider tree" of the provider matching ```` to be returned. 1.15 Add 'last-modified' and 'cache-control' headers ---------------------------------------------------- .. versionadded:: Queens Throughout the API, 'last-modified' headers have been added to GET responses and those PUT and POST responses that have bodies. The value is either the actual last modified time of the most recently modified associated database entity or the current time if there is no direct mapping to the database. In addition, 'cache-control: no-cache' headers are added where the 'last-modified' header has been added to prevent inadvertent caching of resources. 1.16 Limit allocation candidates -------------------------------- .. versionadded:: Queens Add support for a ``limit`` query parameter when making a ``GET /allocation_candidates`` request. The parameter accepts an integer value, ``N``, which limits the maximum number of candidates returned. 1.17 Add 'required' parameter to the allocation candidates (Maximum in Queens) ------------------------------------------------------------------------------ .. versionadded:: Queens Add the ``required`` parameter to the ``GET /allocation_candidates`` API. It accepts a list of traits separated by ``,``. The provider summary in the response will include the attached traits also. 1.18 Support ?required= queryparam on GET /resource_providers --------------------------------------------------------------------- .. versionadded:: Rocky Add support for the ``required`` query parameter to the ``GET /resource_providers`` API. It accepts a comma-separated list of string trait names. When specified, the API results will be filtered to include only resource providers marked with all the specified traits. This is in addition to (logical AND) any filtering based on other query parameters. Trait names which are empty, do not exist, or are otherwise invalid will result in a 400 error. 1.19 Include generation and conflict detection in provider aggregates APIs -------------------------------------------------------------------------- .. versionadded:: Rocky Enhance the payloads for the ``GET /resource_providers/{uuid}/aggregates`` response and the ``PUT /resource_providers/{uuid}/aggregates`` request and response to be identical, and to include the ``resource_provider_generation``. As with other generation-aware APIs, if the ``resource_provider_generation`` specified in the ``PUT`` request does not match the generation known by the server, a 409 Conflict error is returned. 1.20 Return 200 with provider payload from POST /resource_providers ------------------------------------------------------------------- .. versionadded:: Rocky The ``POST /resource_providers`` API, on success, returns 200 with a payload representing the newly-created resource provider, in the same format as the corresponding ``GET /resource_providers/{uuid}`` call. This is to allow the caller to glean automatically-set fields, such as UUID and generation, without a subsequent GET. 1.21 Support ?member_of= queryparam on GET /allocation_candidates ----------------------------------------------------------------------------- .. versionadded:: Rocky Add support for the ``member_of`` query parameter to the ``GET /allocation_candidates`` API. It accepts a comma-separated list of UUIDs for aggregates. Note that if more than one aggregate UUID is passed, the comma-separated list must be prefixed with the "in:" operator. If this parameter is provided, the only resource providers returned will be those in one of the specified aggregates that meet the other parts of the request. 1.22 Support forbidden traits on resource providers and allocations candidates ------------------------------------------------------------------------------ .. versionadded:: Rocky Add support for expressing traits which are forbidden when filtering ``GET /resource_providers`` or ``GET /allocation_candidates``. A forbidden trait is a properly formatted trait in the existing ``required`` parameter, prefixed by a ``!``. For example ``required=!STORAGE_DISK_SSD`` asks that the results not include any resource providers that provide solid state disk. 1.23 Include code attribute in JSON error responses --------------------------------------------------- .. versionadded:: Rocky JSON formatted error responses gain a new attribute, ``code``, with a value that identifies the type of this error. This can be used to distinguish errors that are different but use the same HTTP status code. Any error response which does not specifically define a code will have the code ``placement.undefined_code``. 1.24 Support multiple ?member_of queryparams -------------------------------------------- .. versionadded:: Rocky Add support for specifying multiple ``member_of`` query parameters to the ``GET /resource_providers`` API. When multiple ``member_of`` query parameters are found, they are AND'd together in the final query. For example, issuing a request for ``GET /resource_providers?member_of=agg1&member_of=agg2`` means get the resource providers that are associated with BOTH agg1 and agg2. Issuing a request for ``GET /resource_providers?member_of=in:agg1,agg2&member_of=agg3`` means get the resource providers that are associated with agg3 and are also associated with *any of* (agg1, agg2). 1.25 Granular resource requests to ``GET /allocation_candidates`` ----------------------------------------------------------------- .. versionadded:: Rocky ``GET /allocation_candidates`` is enhanced to accept numbered groupings of resource, required/forbidden trait, and aggregate association requests. A ``resources`` query parameter key with a positive integer suffix (e.g. ``resources42``) will be logically associated with ``required`` and/or ``member_of`` query parameter keys with the same suffix (e.g. ``required42``, ``member_of42``). The resources, required/forbidden traits, and aggregate associations in that group will be satisfied by the same resource provider in the response. When more than one numbered grouping is supplied, the ``group_policy`` query parameter is required to indicate how the groups should interact. With ``group_policy=none``, separate groupings - numbered or unnumbered - may or may not be satisfied by the same provider. With ``group_policy=isolate``, numbered groups are guaranteed to be satisfied by *different* providers - though there may still be overlap with the unnumbered group. In all cases, each ``allocation_request`` will be satisfied by providers in a single non-sharing provider tree and/or sharing providers associated via aggregate with any of the providers in that tree. The ``required`` and ``member_of`` query parameters for a given group are optional. That is, you may specify ``resources42=XXX`` without a corresponding ``required42=YYY`` or ``member_of42=ZZZ``. However, the reverse (specifying ``required42=YYY`` or ``member_of42=ZZZ`` without ``resources42=XXX``) will result in an error. The semantic of the (unnumbered) ``resources``, ``required``, and ``member_of`` query parameters is unchanged: the resources, traits, and aggregate associations specified thereby may be satisfied by any provider in the same non-sharing tree or associated via the specified aggregate(s). 1.26 Allow inventories to have reserved value equal to total ------------------------------------------------------------ .. versionadded:: Rocky Starting with this version, it is allowed to set the reserved value of the resource provider inventory to be equal to total. 1.27 Include all resource class inventories in provider_summaries ----------------------------------------------------------------- .. versionadded:: Rocky Include all resource class inventories in the ``provider_summaries`` field in response of the ``GET /allocation_candidates`` API even if the resource class is not in the requested resources. 1.28 Consumer generation support -------------------------------- .. versionadded:: Rocky A new generation field has been added to the consumer concept. Consumers are the actors that are allocated resources in the placement API. When an allocation is created, a consumer UUID is specified. Starting with microversion 1.8, a project and user ID are also required. If using microversions prior to 1.8, these are populated from the ``incomplete_consumer_project_id`` and ``incomplete_consumer_user_id`` config options from the ``[placement]`` section. The consumer generation facilitates safe concurrent modification of an allocation. A consumer generation is now returned from the following URIs: ``GET /resource_providers/{uuid}/allocations`` The response continues to be a dict with a key of ``allocations``, which itself is a dict, keyed by consumer UUID, of allocations against the resource provider. For each of those dicts, a ``consumer_generation`` field will now be shown. ``GET /allocations/{consumer_uuid}`` The response continues to be a dict with a key of ``allocations``, which itself is a dict, keyed by resource provider UUID, of allocations being consumed by the consumer with the ``{consumer_uuid}``. The top-level dict will also now contain a ``consumer_generation`` field. The value of the ``consumer_generation`` field is opaque and should only be used to send back to subsequent operations on the consumer's allocations. The ``PUT /allocations/{consumer_uuid}`` URI has been modified to now require a ``consumer_generation`` field in the request payload. This field is required to be ``null`` if the caller expects that there are no allocations already existing for the consumer. Otherwise, it should contain the generation that the caller understands the consumer to be at the time of the call. A ``409 Conflict`` will be returned from ``PUT /allocations/{consumer_uuid}`` if there was a mismatch between the supplied generation and the consumer's generation as known by the server. Similarly, a ``409 Conflict`` will be returned if during the course of replacing the consumer's allocations another process concurrently changed the consumer's allocations. This allows the caller to react to the concurrent write by re-reading the consumer's allocations and re-issuing the call to replace allocations as needed. The ``PUT /allocations/{consumer_uuid}`` URI has also been modified to accept an empty allocations object, thereby bringing it to parity with the behaviour of ``POST /allocations``, which uses an empty allocations object to indicate that the allocations for a particular consumer should be removed. Passing an empty allocations object along with a ``consumer_generation`` makes ``PUT /allocations/{consumer_uuid}`` a **safe** way to delete allocations for a consumer. The ``DELETE /allocations/{consumer_uuid}`` URI remains unsafe to call in deployments where multiple callers may simultaneously be attempting to modify a consumer's allocations. The ``POST /allocations`` URI variant has also been changed to require a ``consumer_generation`` field in the request payload **for each consumer involved in the request**. Similar responses to ``PUT /allocations/{consumer_uuid}`` are returned when any of the consumers generations conflict with the server's view of those consumers or if any of the consumers involved in the request are modified by another process. .. warning:: In all cases, it is absolutely **NOT SAFE** to create and modify allocations for a consumer using different microversions where one of the microversions is prior to 1.28. The only way to safely modify allocations for a consumer and satisfy expectations you have regarding the prior existence (or lack of existence) of those allocations is to always use microversion 1.28+ when calling allocations API endpoints. 1.29 Support allocation candidates with nested resource providers ----------------------------------------------------------------- .. versionadded:: Rocky Add support for nested resource providers with the following two features. 1) ``GET /allocation_candidates`` is aware of nested providers. Namely, when provider trees are present, ``allocation_requests`` in the response of ``GET /allocation_candidates`` can include allocations on combinations of multiple resource providers in the same tree. 2) ``root_provider_uuid`` and ``parent_provider_uuid`` are added to ``provider_summaries`` in the response of ``GET /allocation_candidates``. 1.30 Provide a /reshaper resource (Maximum in Rocky) ---------------------------------------------------- .. versionadded:: Rocky Add support for a ``POST /reshaper`` resource that provides for atomically migrating resource provider inventories and associated allocations when some of the inventory moves from one resource provider to another, such as when a class of inventory moves from a parent provider to a new child provider. .. note:: This is a special operation that should only be used in rare cases of resource provider topology changing when inventory is in use. Only use this if you are really sure of what you are doing.