Solum/API
Blueprint: https://blueprints.launchpad.net/solum/+spec/api
Proposed By: Adrian Otto
Review comments here: https://etherpad.openstack.org/p/solum-api-spec-review
Contents
API
Synopsis
Verb | URI | Description |
---|---|---|
GET | / | Get the root Platform resource
|
GET | /assemblies | Get a list of the Assembly resources for this tenant
|
POST | /assemblies | Create a new Assembly resource
|
GET | /assemblies/{id} | Get a specific Assembly resource
|
PUT | /assemblies/{id} | Update a complete Assembly resource
|
PATCH | /assemblies/{id} | Update select attributes of an Assembly resource
|
DELETE | /assemblies/{id} | Delete this Assembly resource.
|
GET | /components | Get a list of the Component resources for this tenant
|
POST | /components | Create a new Component resource
|
GET | /components/{id} | Get a specific Component resource
|
PUT | /components/{id} | Update a complete Component resource
|
PATCH | /components/{id} | Update select attributes of an Component resource
|
DELETE | /components/{id} | Delete this Component resource.
|
GET | /services | Get a list of the Service resources for this tenant
|
POST | /services | Create a new Service resource
|
GET | /services/{id} | Get a specific Service resource
|
PUT | /services/{id} | Update a complete Service resource
|
PATCH | /services/{id} | Update select attributes of an Service resource
|
DELETE | /services/{id} | Delete this Service resource.
|
GET | /extensions | Get a list of the Extension resources for this tenant
|
GET | /extensions/{id} | Get a specific Extension resource
|
API Concepts
This section provides an overview of the different aspects of the API, and what they represent. See also: Definitions with a conceptual diagram.
Basics
Roles
Provider
The organization offering hosted platform services to its customers.
Consumer
The individual customer that uses the hosted Platform.
Platform
The Platform
resource is the root level resource that refers to all the other resources owned by this tenant.
Assembly
The Assembly
resource represents a group of components that make up a running instance of an application. You may casually refer to this as "the application" but we refer to it as an Assembly because most cloud applications are actually a system of multiple service instances that make up a system. For example, a three-tier web application may have a load balancer component, a group of application servers, and a database server all represented as Component
resources that make up an Assembly
resource. An Assembly
resource has at least one Component
resource associated with it.
Component
The Component
resource represents one part of an Assembly needed by your application. For example, an instance of a database service may be a Component
. A Component
resource may also represent a static artifact, such as an archive file that contains data for initializing your application. An Assembly
may have different components that represent different processes that run. For example, you may have one Component
that represents an API service process, and another that represents a web UI process that consumes that API service. This simplest case is when an Assembly
has only one component. For examaple your component may be named "PHP" and refers to the PHP Service offered by the platform for running a PHP application.
Service
The Service
resource represents a networked service provided by a Platform
Provider. You may create Component
resources that refer to Service resources. The Component
represents an instance of the Service
. Your application may use that service remotely over the network, and the Component
is how it gets clues about how to connect to it, such as attributes defining a connection URL. In this usage, the Component
is a virtual representation of a service provided elsewhere (by another application, or by a Platform
Provider). For example, the Platform
may offer a default Service named "mysql". You may create multiple Component
resources that reference different instances of the "mysql" service. Each Component
may represent a multi-tenant instance of a MySQL database (perhaps a logical database) service offered by the Platform for a given Assembly
.
Advanced
Extension
The Extension
resource represents changes that the Provider has added onto a Platform in addition to the ones supplied by Solum by default. This may include additional protocol semantics, resource types, application lifecycle states, etc. Anything may be added, as long as it does not contradict the base functionality offered by Solum.
Operation
The Operation
resource represents an action that can be taken on a resource. Operations can be added to Assembly
, Component
, or Service
resources.
Sensor
The Sensor
resource represents an dynamic data that can be collected from a resource. For example, statistics about the access rate of a resource (usually a Component
). Sensors can be added to Assembly
, Component
, or Service
resources.
Types
This section details the different data types used by the API.
Boolean
As defined by JSON [RFC4627], a token having a literal value of either true or false.
String
A UNICODE string as defined by JSON [RFC4627].
URI
A String (see above) that conforms to the syntax defined in [RFC3986].
Link
Relation used for a resource entity has attribute values that link to other resource entities. For example, a Platform resource entity attribute values points to assemblies. The “Link” type defined here is used for such attribute values. It is typically only used as an array of Link entities.
{ "href": URI, "targetName": String }
The following attributes are present in a Link. Other attributes, not defined in this specification, may also be present.
href
This attribute is the URI [RFC3986] of the resource referenced by this Link. The value of this attribute may be changed by the Provider. Consumers may not change the value of this attribute.
targetName
This attribute echoes the value of the “name” attribute of the resource referenced by this Link. The value of this attribute may be changed by the Platform. Consumers may not change the value of this attribute.
Protocol and Resource Representations
This section shows the representation of each of the resources in JSON format, and how you interact with them through the REST API. Note: The Link[] type indicates an array of Links. A "?" character indicates the attribute is optional.
Platform
The Platform
resource is the root level resource that refers to all the other resources owned by this tenant. The purpose of the Platform
resource is for API introspection.
Verb | URI | Description |
---|---|---|
GET | / | Get the root Platform resource
|
{ "uri": URI, "name": String, "type": "platform", "description": String ?, "extensionsUri": "/extensions", "implementationVersion": String ?, "assemblies": Link[] ?, "components": Link[] ?, "services": Link[] ?, "parameterDefinitionsUri": URI }
Assembly
The Assembly
resource represents a group of components that make up a running instance of an application. You may casually refer to this as "the application" but we refer to it as an Assembly because most cloud applications are actually a system of multiple service instances that make up a system. For example, a three-tier web application may have a load balancer component, a group of application servers, and a database server all represented as Component
resources that make up an Assembly
resource. An Assembly
resource has at least one Component
resource associated with it.
Verb | URI | Description |
---|---|---|
GET | /assemblies | Get a list of the Assembly resources for this tenant
|
POST | /assemblies | Create a new Assembly resource
|
GET | /assemblies/{id} | Get a specific Assembly resource
|
PUT | /assemblies/{id} | Update a complete Assembly resource
|
PATCH | /assemblies/{id} | Update select attributes of an Assembly resource
|
DELETE | /assemblies/{id} | Delete this Assembly resource.
|
{ "uri": URI, "name": String, "type": "assembly", "description": String ?, "Components": Link[] ?, "operationsUri": URI ?, "sensorsUri": URI ? }
Component
The Component
resource represents one part of an Assembly needed by your application. For example, an instance of a database service may be a Component
. A Component
resource may also represent a static artifact, such as an archive file that contains data for initializing your application. An Assembly
may have different components that represent different processes that run. For example, you may have one Component
that represents an API service process, and another that represents a web UI process that consumes that API service. This simplest case is when an Assembly
has only one component. For exmaple your component may be named "PHP" and refers to the PHP Service offered by the platform for running a PHP application.
Verb | URI | Description |
---|---|---|
GET | /components | Get a list of the Component resources for this tenant
|
POST | /components | Create a new Component resource
|
GET | /components/{id} | Get a specific Component resource
|
PUT | /components/{id} | Update a complete Component resource
|
PATCH | /components/{id} | Update select attributes of an Component resource
|
DELETE | /components/{id} | Delete this Component resource.
|
{ "uri": URI, "name": String, "type": "component", "description": String ?, "tags": String[] ?, "assembly": Link, "components": Link[] ?, "services": Link[] ?, "operationsUri": URI ?, "sensorsUri": URI ? }
Service
The Service
resource represents a networked service provided by a Platform
Provider. You may create Component
resources that refer to Service resources. The Component
represents an instance of the Service
. Your application connects to the Component that using a network protocol. For example, the Platform
may offer a default Service named "mysql". You may create multiple Component
resources that reference different instances of the "mysql" service. Each Component
may be a multi-tenant instance of a MySQL database (perhaps a logical database) service offered by the Platform for a given Assembly
.
Services Resource
Verb | URI | Description |
---|---|---|
GET | /services | Get a list of the Service resources for this tenant
|
POST | /services | Create a new Service resource
|
Plural representation (list):
Request: GET /services ... Response: { "uri": URI, "name": String, "type": "services", "description": String, ? "serviceLinks": Link[] }
Service Resource
GET | /services/{id} | Get a specific Service resource
|
PUT | /services/{id} | Update a complete Service resource (subject to access control rules)
|
PATCH | /services/{id} | Update select attributes of an Service resource (subject to access control rules)
|
DELETE | /services/{id} | Delete this Service resource. (subject to access control rules)
|
Singular representation:
Request: GET /service/{id} ... Response: { "uri": URI, "name": String, "type": "service", "description": String ?, "tags": String[] ?, "operationsUri": URI ?, "sensorsUri": URI ?, "readOnly": Boolean }
Note: Solum prohibits PUT, PATCH, and DELETE calls on the Services provided as part of the base configuration offered by the Provider. In this case the readOnly attribute will be set to TRUE. Services added by a tenant will have a readOnly attribute set to FALSE, and may be modified or deleted by that same tenant.
Extension
The Extension
resource represents changes that the Provider has added onto a Platform in addition to the ones supplied by Solum by default. This may include additional protocol semantics, resource types, application lifecycle states, resource attributes, etc. Anything may be added, as long as it does not contradict the base functionality offered by Solum.
Extensions Resource
Verb | URI | Description |
---|---|---|
GET | /extensions | Get a list of the Extension resources for this tenant
|
Plural representation (list):
{ "uri": URI, "name": String, "type": "extensions", "description": String, ? "extensionLinks": Link[] }
Extension Resource
Verb | URI | Description |
---|---|---|
GET | /extensions/{id} | Get a specific Extension resource
|
Singular representation:
{ "uri": URI, "name": String, "type": "extension", "description": String, "version": String, "documentation": URI ? }
Operation
An Operation
resource represents an operation or action available on a target resource. This is for defining actions that may change the state of the resource they are related to. For example, the API already provides ways to register, start, and stop your application (POST an Assembly
to register+start, and DELETE an Assembly
to stop) but Operations provide a way to extend the system to add your own actions such as "pause" and "resume", or "scale_up" and "scale_down". It has the following representation:
Operations Resource
Verb | URI | Description |
---|---|---|
GET | /operations | Get a list of the Operation resources for this tenant
|
POST | /operations | Create a new Operation resource
|
The plural representation (list):
Request: GET /operations ... Response: { "uri": URI, "name": String, "type": "operations", "description": String ?, "targetResource": URI, "operationLinks": Link[] }
Operation Resource
Verb | URI | Description |
---|---|---|
GET | /operations/{id} | Get a specific Operation resource
|
PUT | /operations/{id} | Update a complete Operation resource
|
PATCH | /operations/{id} | Update an attribute of an Operation resource
|
DELETE | /operations/{id} | Delete a specific Operation resource
|
The singular representation:
Request: GET /operations/{id} ... Response: { "uri": URI, "name": String, "type": "operation", "description": String ?, "documentation": URI, "targetResource": URI }
Note that the documentation
attribute is a link to (probably a PDF) document that explains the semantics of the operation you are defining. This is a lightweight method of allowing the API to be extensible without requiring a markup language.
Sensor
A Sensor
resource represents exactly one supported sensor on one or more resources. Sensor
resources represent dynamic data about resources, such as metrics or state. Sensor
resources are useful for exposing data that changes rapidly, or that may need to be fetched from a secondary system. It has the following representation:
Sensors Resource
Verb | URI | Description |
---|---|---|
GET | /sensors | Get a a list of Sensor resources for this tenant
|
POST | /sensors | Create a new Sensor resource
|
The plural representation (list):
Request: GET /sensors ... Response: { "uri": URI, "name": String, "type": "sensors", "description": String ?, "targetResource": URI, "sensorLinks": Link[] }
Sensor Resource
Verb | URI | Description |
---|---|---|
GET | /sensors/{id} | Get a specific Sensor resource
|
PUT | /sensors/{id} | Update a complete Sensor resource
|
PATCH | /sensors/{id} | Update an attribute of an Sensor resource
|
DELETE | /sensors/{id} | Delete a specific Sensor resource
|
The singular representation:
Request: GET /sensors/{id} ... Response: { "uri": URI, "name": String, "type": "sensor", "description": String ?, "documentation": URI, "targetResource": URI, "sensorType": String, "value": <sensorType> ?, "timestamp": Timestamp ?, "operationsUri": URI ? }