templates

« Previous section Next section »

UCloud Developer Guide / Orchestration of Resources / Storage / Metadata / Metadata Templates

Metadata Templates

Metadata templates define the schema for metadata documents.

Rationale

📝 NOTE: This API follows the standard Resources API. We recommend that you have already read and understood the concepts described here.


UCloud supports arbitrary of files. This feature is useful for general data management. It allows users to tag documents at a glance and search through them.

This feature consists of two parts:

  1. Metadata templates (you are here): Templates specify the schema. You can think of this as a way of defining how your documents should look. We use them to generate user interfaces and visual representations of your documents.

  2. Metadata documents (next section): Documents fill out the values of a template. When you create a document you must attach it to a file also.

At a technical level, we implement metadata templates using JSON schema. This gives you a fair amount of flexibility to control the format of documents. Of course, not everything is machine-checkable. To mitigate this, templates can require that changes go through an approval process. Only administrators of a workspace can approve such changes.

Table of Contents

1. Examples

2. Remote Procedure Calls

3. Data Models

Example: The Sensitivity Template

Frequency of useCommon

Actors

  • An authenticated user (user)

Communication Flow: Kotlin
FileMetadataTemplateNamespaces.createTemplate.call(
    bulkRequestOf(FileMetadataTemplate(
        changeLog = "Initial version", 
        createdAt = 0, 
        description = "File sensitivity for files", 
        inheritable = true, 
        namespaceId = "sensitivity", 
        namespaceName = null, 
        namespaceType = FileMetadataTemplateNamespaceType.COLLABORATORS, 
        requireApproval = true, 
        schema = JsonObject(mapOf("type" to JsonLiteral(
            coerceToInlineType = null, 
            content = "object", 
            isString = true, 
        )),"title" to JsonLiteral(
            coerceToInlineType = null, 
            content = "UCloud File Sensitivity", 
            isString = true, 
        )),"required" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "sensitivity", 
            isString = true, 
        ))),"properties" to JsonObject(mapOf("sensitivity" to JsonObject(mapOf("enum" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "SENSITIVE", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "CONFIDENTIAL", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "PRIVATE", 
            isString = true, 
        ))),"type" to JsonLiteral(
            coerceToInlineType = null, 
            content = "string", 
            isString = true, 
        )),"title" to JsonLiteral(
            coerceToInlineType = null, 
            content = "File Sensitivity", 
            isString = true, 
        )),"enumNames" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "Sensitive", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "Confidential", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "Private", 
            isString = true, 
        ))),))),))),"dependencies" to JsonObject(mapOf())),)), 
        title = "Sensitivity", 
        uiSchema = JsonObject(mapOf("ui:order" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "sensitivity", 
            isString = true, 
        ))),)), 
        version = "1.0.0", 
    )),
    user
).orThrow()

/*
BulkResponse(
    responses = listOf(FileMetadataTemplateAndVersion(
        id = "15123", 
        version = "1.0.0", 
    )), 
)
*/
FileMetadataTemplateNamespaces.retrieveLatest.call(
    FindByStringId(
        id = "15123", 
    ),
    user
).orThrow()

/*
FileMetadataTemplate(
    changeLog = "Initial version", 
    createdAt = 0, 
    description = "File sensitivity for files", 
    inheritable = true, 
    namespaceId = "sensitivity", 
    namespaceName = null, 
    namespaceType = FileMetadataTemplateNamespaceType.COLLABORATORS, 
    requireApproval = true, 
    schema = JsonObject(mapOf("type" to JsonLiteral(
        coerceToInlineType = null, 
        content = "object", 
        isString = true, 
    )),"title" to JsonLiteral(
        coerceToInlineType = null, 
        content = "UCloud File Sensitivity", 
        isString = true, 
    )),"required" to listOf(JsonLiteral(
        coerceToInlineType = null, 
        content = "sensitivity", 
        isString = true, 
    ))),"properties" to JsonObject(mapOf("sensitivity" to JsonObject(mapOf("enum" to listOf(JsonLiteral(
        coerceToInlineType = null, 
        content = "SENSITIVE", 
        isString = true, 
    ), JsonLiteral(
        coerceToInlineType = null, 
        content = "CONFIDENTIAL", 
        isString = true, 
    ), JsonLiteral(
        coerceToInlineType = null, 
        content = "PRIVATE", 
        isString = true, 
    ))),"type" to JsonLiteral(
        coerceToInlineType = null, 
        content = "string", 
        isString = true, 
    )),"title" to JsonLiteral(
        coerceToInlineType = null, 
        content = "File Sensitivity", 
        isString = true, 
    )),"enumNames" to listOf(JsonLiteral(
        coerceToInlineType = null, 
        content = "Sensitive", 
        isString = true, 
    ), JsonLiteral(
        coerceToInlineType = null, 
        content = "Confidential", 
        isString = true, 
    ), JsonLiteral(
        coerceToInlineType = null, 
        content = "Private", 
        isString = true, 
    ))),))),))),"dependencies" to JsonObject(mapOf())),)), 
    title = "Sensitivity", 
    uiSchema = JsonObject(mapOf("ui:order" to listOf(JsonLiteral(
        coerceToInlineType = null, 
        content = "sensitivity", 
        isString = true, 
    ))),)), 
    version = "1.0.0", 
)
*/
FileMetadataTemplateNamespaces.browseTemplates.call(
    FileMetadataTemplatesBrowseTemplatesRequest(
        consistency = null, 
        id = "15123", 
        itemsPerPage = null, 
        itemsToSkip = null, 
        next = null, 
    ),
    user
).orThrow()

/*
PageV2(
    items = listOf(FileMetadataTemplate(
        changeLog = "Initial version", 
        createdAt = 0, 
        description = "File sensitivity for files", 
        inheritable = true, 
        namespaceId = "sensitivity", 
        namespaceName = null, 
        namespaceType = FileMetadataTemplateNamespaceType.COLLABORATORS, 
        requireApproval = true, 
        schema = JsonObject(mapOf("type" to JsonLiteral(
            coerceToInlineType = null, 
            content = "object", 
            isString = true, 
        )),"title" to JsonLiteral(
            coerceToInlineType = null, 
            content = "UCloud File Sensitivity", 
            isString = true, 
        )),"required" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "sensitivity", 
            isString = true, 
        ))),"properties" to JsonObject(mapOf("sensitivity" to JsonObject(mapOf("enum" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "SENSITIVE", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "CONFIDENTIAL", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "PRIVATE", 
            isString = true, 
        ))),"type" to JsonLiteral(
            coerceToInlineType = null, 
            content = "string", 
            isString = true, 
        )),"title" to JsonLiteral(
            coerceToInlineType = null, 
            content = "File Sensitivity", 
            isString = true, 
        )),"enumNames" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "Sensitive", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "Confidential", 
            isString = true, 
        ), JsonLiteral(
            coerceToInlineType = null, 
            content = "Private", 
            isString = true, 
        ))),))),))),"dependencies" to JsonObject(mapOf())),)), 
        title = "Sensitivity", 
        uiSchema = JsonObject(mapOf("ui:order" to listOf(JsonLiteral(
            coerceToInlineType = null, 
            content = "sensitivity", 
            isString = true, 
        ))),)), 
        version = "1.0.0", 
    )), 
    itemsPerPage = 50, 
    next = null, 
)
*/
FileMetadataTemplateNamespaces.browse.call(
    ResourceBrowseRequest(
        consistency = null, 
        flags = FileMetadataTemplateNamespaceFlags(
            filterCreatedAfter = null, 
            filterCreatedBefore = null, 
            filterCreatedBy = null, 
            filterIds = null, 
            filterName = null, 
            filterProductCategory = null, 
            filterProductId = null, 
            filterProvider = null, 
            filterProviderIds = null, 
            hideProductCategory = null, 
            hideProductId = null, 
            hideProvider = null, 
            includeOthers = false, 
            includeProduct = false, 
            includeSupport = false, 
            includeUpdates = false, 
        ), 
        itemsPerPage = null, 
        itemsToSkip = null, 
        next = null, 
        sortBy = null, 
        sortDirection = null, 
    ),
    user
).orThrow()

/*
PageV2(
    items = listOf(FileMetadataTemplateNamespace(
        createdAt = 1635151675465, 
        id = "15123", 
        owner = ResourceOwner(
            createdBy = "user", 
            project = null, 
        ), 
        permissions = ResourcePermissions(
            myself = listOf(Permission.ADMIN), 
            others = emptyList(), 
        ), 
        specification = FileMetadataTemplateNamespace.Spec(
            name = "sensitivity", 
            namespaceType = FileMetadataTemplateNamespaceType.COLLABORATORS, 
            product = ProductReference(
                category = "", 
                id = "", 
                provider = "ucloud_core", 
            ), 
        ), 
        status = FileMetadataTemplateNamespace.Status(
            latestTitle = "Sensitivity", 
            resolvedProduct = null, 
            resolvedSupport = null, 
        ), 
        updates = emptyList(), 
        providerGeneratedId = "15123", 
    )), 
    itemsPerPage = 50, 
    next = null, 
)
*/
Communication Flow: Curl
# ------------------------------------------------------------------------------------------------------
# $host is the UCloud instance to contact. Example: 'http://localhost:8080' or 'https://cloud.sdu.dk'
# $accessToken is a valid access-token issued by UCloud
# ------------------------------------------------------------------------------------------------------

# Authenticated as user
curl -XPOST -H "Authorization: Bearer $accessToken" -H "Content-Type: content-type: application/json; charset=utf-8" "$host/api/files/metadataTemplates/templates" -d '{
    "items": [
        {
            "namespaceId": "sensitivity",
            "title": "Sensitivity",
            "version": "1.0.0",
            "schema": {
                "type": "object",
                "title": "UCloud File Sensitivity",
                "required": [
                    "sensitivity"
                ],
                "properties": {
                    "sensitivity": {
                        "enum": [
                            "SENSITIVE",
                            "CONFIDENTIAL",
                            "PRIVATE"
                        ],
                        "type": "string",
                        "title": "File Sensitivity",
                        "enumNames": [
                            "Sensitive",
                            "Confidential",
                            "Private"
                        ]
                    }
                },
                "dependencies": {
                }
            },
            "inheritable": true,
            "requireApproval": true,
            "description": "File sensitivity for files",
            "changeLog": "Initial version",
            "namespaceType": "COLLABORATORS",
            "uiSchema": {
                "ui:order": [
                    "sensitivity"
                ]
            },
            "namespaceName": null,
            "createdAt": 0
        }
    ]
}'


# {
#     "responses": [
#         {
#             "id": "15123",
#             "version": "1.0.0"
#         }
#     ]
# }

curl -XGET -H "Authorization: Bearer $accessToken" "$host/api/files/metadataTemplates/retrieveLatest?id=15123" 

# {
#     "namespaceId": "sensitivity",
#     "title": "Sensitivity",
#     "version": "1.0.0",
#     "schema": {
#         "type": "object",
#         "title": "UCloud File Sensitivity",
#         "required": [
#             "sensitivity"
#         ],
#         "properties": {
#             "sensitivity": {
#                 "enum": [
#                     "SENSITIVE",
#                     "CONFIDENTIAL",
#                     "PRIVATE"
#                 ],
#                 "type": "string",
#                 "title": "File Sensitivity",
#                 "enumNames": [
#                     "Sensitive",
#                     "Confidential",
#                     "Private"
#                 ]
#             }
#         },
#         "dependencies": {
#         }
#     },
#     "inheritable": true,
#     "requireApproval": true,
#     "description": "File sensitivity for files",
#     "changeLog": "Initial version",
#     "namespaceType": "COLLABORATORS",
#     "uiSchema": {
#         "ui:order": [
#             "sensitivity"
#         ]
#     },
#     "namespaceName": null,
#     "createdAt": 0
# }

curl -XGET -H "Authorization: Bearer $accessToken" "$host/api/files/metadataTemplates/browseTemplates?id=15123" 

# {
#     "itemsPerPage": 50,
#     "items": [
#         {
#             "namespaceId": "sensitivity",
#             "title": "Sensitivity",
#             "version": "1.0.0",
#             "schema": {
#                 "type": "object",
#                 "title": "UCloud File Sensitivity",
#                 "required": [
#                     "sensitivity"
#                 ],
#                 "properties": {
#                     "sensitivity": {
#                         "enum": [
#                             "SENSITIVE",
#                             "CONFIDENTIAL",
#                             "PRIVATE"
#                         ],
#                         "type": "string",
#                         "title": "File Sensitivity",
#                         "enumNames": [
#                             "Sensitive",
#                             "Confidential",
#                             "Private"
#                         ]
#                     }
#                 },
#                 "dependencies": {
#                 }
#             },
#             "inheritable": true,
#             "requireApproval": true,
#             "description": "File sensitivity for files",
#             "changeLog": "Initial version",
#             "namespaceType": "COLLABORATORS",
#             "uiSchema": {
#                 "ui:order": [
#                     "sensitivity"
#                 ]
#             },
#             "namespaceName": null,
#             "createdAt": 0
#         }
#     ],
#     "next": null
# }

curl -XGET -H "Authorization: Bearer $accessToken" "$host/api/files/metadataTemplates/browse?includeOthers=false&includeUpdates=false&includeSupport=false&includeProduct=false" 

# {
#     "itemsPerPage": 50,
#     "items": [
#         {
#             "id": "15123",
#             "specification": {
#                 "name": "sensitivity",
#                 "namespaceType": "COLLABORATORS",
#                 "product": {
#                     "id": "",
#                     "category": "",
#                     "provider": "ucloud_core"
#                 }
#             },
#             "createdAt": 1635151675465,
#             "status": {
#                 "latestTitle": "Sensitivity",
#                 "resolvedSupport": null,
#                 "resolvedProduct": null
#             },
#             "updates": [
#             ],
#             "owner": {
#                 "createdBy": "user",
#                 "project": null
#             },
#             "permissions": {
#                 "myself": [
#                     "ADMIN"
#                 ],
#                 "others": [
#                 ]
#             }
#         }
#     ],
#     "next": null
# }
Communication Flow: Visual

Remote Procedure Calls

browse

Browses the catalog of available resources

browseTemplates

retrieve

Retrieve a single resource

retrieveLatest

retrieveProducts

Retrieve product support for all accessible providers

This endpoint will determine all providers that which the authenticated user has access to, in the current workspace. A user has access to a product, and thus a provider, if the product is either free or if the user has been granted credits to use the product.

See also:

retrieveTemplate

create

Creates one or more resources

createTemplate

deprecate

init

Request (potential) initialization of resources

RequestResponseError

This request is sent by the client, if the client believes that initialization of resources might be needed. NOTE: This request might be sent even if initialization has already taken place. UCloud/Core does not check if initialization has already taken place, it simply validates the request.

updateAcl

Updates the ACL attached to a resource

Data Models

FileMetadataTemplateAndVersion

data class FileMetadataTemplateAndVersion(
    val id: String,
    val version: String,
)
Properties


FileMetadataTemplateNamespace

A Resource is the core data model used to synchronize tasks between UCloud and Provider.

data class FileMetadataTemplateNamespace(
    val id: String,
    val specification: FileMetadataTemplateNamespace.Spec,
    val createdAt: Long,
    val status: FileMetadataTemplateNamespace.Status,
    val updates: List<FileMetadataTemplateNamespace.Update>,
    val owner: ResourceOwner,
    val permissions: ResourcePermissions?,
    val providerGeneratedId: String?,
)

For more information go here.

Properties


FileMetadataTemplateNamespace.Spec

data class Spec(
    val name: String,
    val namespaceType: FileMetadataTemplateNamespaceType,
    val product: ProductReference,
)
Properties


FileMetadataTemplateNamespace.Status

Describes the current state of the Resource

data class Status(
    val latestTitle: String?,
    val resolvedSupport: ResolvedSupport<Product, FileMetadataTemplateSupport>?,
    val resolvedProduct: Product?,
)

The contents of this field depends almost entirely on the specific Resource that this field is managing. Typically, this will contain information such as:

  • A state value. For example, a compute Job might be RUNNING

  • Key metrics about the resource.

  • Related resources. For example, certain Resources are bound to another Resource in a mutually exclusive way, this should be listed in the status section.

Properties


FileMetadataTemplateNamespace.Update

Describes an update to the Resource

data class Update(
    val timestamp: Long,
    val status: String?,
)

Updates can optionally be fetched for a Resource. The updates describe how the Resource changes state over time. The current state of a Resource can typically be read from its status field. Thus, it is typically not needed to use the full update history if you only wish to know the current state of a Resource.

An update will typically contain information similar to the status field, for example:

  • A state value. For example, a compute Job might be RUNNING.

  • Change in key metrics.

  • Bindings to related Resources.

Properties


FileMetadataTemplateNamespaceFlags

data class FileMetadataTemplateNamespaceFlags(
    val includeOthers: Boolean?,
    val includeUpdates: Boolean?,
    val includeSupport: Boolean?,
    val includeProduct: Boolean?,
    val filterCreatedBy: String?,
    val filterCreatedAfter: Long?,
    val filterCreatedBefore: Long?,
    val filterProvider: String?,
    val filterProductId: String?,
    val filterProductCategory: String?,
    val filterProviderIds: String?,
    val filterIds: String?,
    val filterName: String?,
    val hideProductId: String?,
    val hideProductCategory: String?,
    val hideProvider: String?,
)
Properties


FileMetadataTemplateSupport

data class FileMetadataTemplateSupport(
    val product: ProductReference?,
    val maintenance: Maintenance?,
)
Properties


FileMetadataTemplatesBrowseTemplatesRequest

The base type for requesting paginated content.

data class FileMetadataTemplatesBrowseTemplatesRequest(
    val id: String,
    val itemsPerPage: Int?,
    val next: String?,
    val consistency: PaginationRequestV2Consistency?,
    val itemsToSkip: Long?,
)

Paginated content can be requested with one of the following consistency guarantees, this greatly changes the semantics of the call:

ConsistencyDescription

PREFER

Consistency is preferred but not required. An inconsistent snapshot might be returned.

REQUIRE

Consistency is required. A request will fail if consistency is no longer guaranteed.

The consistency refers to if collecting all the results via the pagination API are consistent. We consider the results to be consistent if it contains a complete view at some point in time. In practice this means that the results must contain all the items, in the correct order and without duplicates.

If you use the PREFER consistency then you may receive in-complete results that might appear out-of-order and can contain duplicate items. UCloud will still attempt to serve a snapshot which appears mostly consistent. This is helpful for user-interfaces which do not strictly depend on consistency but would still prefer something which is mostly consistent.

The results might become inconsistent if the client either takes too long, or a service instance goes down while fetching the results. UCloud attempts to keep each next token alive for at least one minute before invalidating it. This does not mean that a client must collect all results within a minute but rather that they must fetch the next page within a minute of the last page. If this is not feasible and consistency is not required then PREFER should be used.


📝 NOTE: Services are allowed to ignore extra criteria of the request if the next token is supplied. This is needed in order to provide a consistent view of the results. Clients should provide the same criterion as they paginate through the results.


Properties


Last updated