http

This Policy Information Point to get and monitor HTTP based information.

This Policy Information Point provides basic means to source attribute data by consuming HTTP-based APIs and Websockets.

The Attributes are named according to the HTTP verb, i.e., get, put, delete, post, and patch. And are available as either environment attributes or attributes of a an URL which semantically identifies a resource used as the left-hand input parameter of the attribute finders.

This PIP is more technical than domain driven and therefore the attributes are specified by defining HTTP requests by defining a requestSetings object, which may contain the following parameters:

• baseUrl: The starting URL to build the request path.
• path: Path components to be appended to the baseUrl.
• urlParameters: An object with key-value pairs representing the HTTP query parameters to be embedded in the request URL.
• headers: An object with key-value pairs representing the HTTP headers.
• body: The request body.
• accept: The accepted mime media type.
• contentType: The mime type of the request body.
• pollingIntervalMs: The number of milliseconds between polling the HTTP endpoint. Defaults to 1000ms.
• repetitions: Upper bound for number of repeated requests. Defaults to 0x7fffffffffffffffL.

For the media type text/event-stream, the attribute finder will treat the consumed endpoint to be sending server-sent events (SSEs) and will not poll the endpoint, but subscribe to the events emitted by the consumed API.

If the accepted media type is application/json, the PIP will attempt to parse it and map the response body to a SAPL value. Else, the response body is returned as a text value.

Example:

{
  "baseUrl": "https://example.com",
  "path": "/api/owners",
  "urlParameters": {
                      "age": 5,
                      "sort": "ascending"
                   },
  "headers": {
               "Authorization": "Bearer <token>",
               "If-Modified-Since": "Tue, 19 Jul 2016 12:22:11 UTC"
             },
  "body": "<tag>abc</tag>",
  "accept": "application/json",
  "contentType": "application/xml",
  "pollingIntervalMs": 4500,
  "repetitions": 999
}

---

patch

Parameters of Attribute Finder

Name: requestSettings [JSON] <patch(OBJECT requestSettings)> is an environment attribute stream and takes no left-hand arguments. This attribute takes a requestSettings object as a parameter and performs the matching HTTP PATCH request and polls it according the the settings.

Example:

policy "http example"
permit
where
  var request = {
                    "baseUrl": "https://example.com",
                    "path": "/status",
                    "body": { "action": "turnOff", "resource": "heater" }
                }
  <http.patch(request)>.status == "off";

---

post

Parameters of Attribute Finder

Name: requestSettings [JSON] <post(OBJECT requestSettings)> is an environment attribute stream and takes no left-hand arguments. This attribute takes a requestSettings object as a parameter and performs the matching HTTP POST request and polls it according the the settings.

Example:

policy "http example"
permit
where
  var request = {
                    "baseUrl": "https://example.com",
                    "path": "/status",
                    "body": { "action": "turnOff", "resource": "heater" }
                }
  <http.post(request)>.status == "off";

---

websocket

Parameters of Attribute Finder

Name: requestSettings [JSON] <websocket(OBJECT requestSettings)> is an environment attribute stream and takes no left-hand arguments. This attribute takes a requestSettings object as a parameter and connects to a Websocket and emits events as sent by the server. Upon connection, the body of the settings is sent to the server.

Example:

policy "http example"
permit
where
  var request = {
                    "baseUrl": "https://example.com",
                    "path": "/status",
                    "body": "message"
                }
  <http.websocket(request)>.health == "GOOD";

---

get

Parameters of Attribute Finder

Name: resourceUrl [TEXT] Name: requestSettings [JSON] (TEXT resourceUrl).<get(OBJECT requestSettings)> is an attribute of the resource identified by the resourceUrl``. This attribute takes arequestSettings``` object as a parameter and performs the matching HTTP GET request and polls it according the the settings.

Example:

policy "http example"
permit
where
  "https://example.com/resources/123".<http.get({ })>.status == "HEALTHY";

---

delete

Parameters of Attribute Finder

Name: resourceUrl [TEXT] Name: requestSettings [JSON] (TEXT resourceUrl).<delete(OBJECT requestSettings)> is an attribute of the resource identified by the resourceUrl``. This attribute takes arequestSettings``` object as a parameter and performs the matching HTTP DELETE request and polls it according the the settings.

Example:

policy "http example"
permit
where
  "https://example.com/resources/123".<http.delete({})> != undefined;

---

put

Parameters of Attribute Finder

Name: resourceUrl [TEXT] Name: requestSettings [JSON] (TEXT resourceUrl).<put(OBJECT requestSettings)> is an attribute of the resource identified by the resourceUrl``. This attribute takes arequestSettings``` object as a parameter and performs the matching HTTP PUT request and polls it according the the settings.

Example:

policy "http example"
permit
where
  "https://example.com/resources/123".<http.put({ body = "\"test\"" })>.status == "OK";

---