Can I use paging when getting service identities from ACS - service

Background
I require a list of all the service identity names I have registered in the Azure ACS. I have an Azure Management Service reference I got from https://myaccesscontrol.accesscontrol.windows.net/v2/mgmt/service. The “myaccesscontrol” prefix is arbitrary, for this discussion. You could use a different subscription namespace prefix and get the same results, if I understand correctly. This is the service endpoint that Azure gives me when I subscribe. It exposes a ManagementService interface. When I get a list of service identities
DataServiceQuery<ServiceIdentity> identities = managementService.ServiceIdentities;
I get back an object that has a count of all the identities I expect. When I expand the list I get the first 50. This is typical of a paged response, and I expect that there is a continuation token that will allow me to get the next “page”.
Problem
I can’t see how the ManagementServiceReference.ManagementService interface can be used to obtain a continuation token.
Discussion
How to: Load Paged Results (WCF Data Services) at http://msdn.microsoft.com/en-us/library/ee358711.aspx provides an example where a QueryOperationResponse response from LINQ context can be queried for continuation with
token = response.GetContinuation()
The QueryOperationResponse is retrieved from a LINQ context Execute().
In some Azure sample code I have, there are examples of paging for blobs, tables, and queues, where data is collected in a ResultSegment. A ResultSegment has a Boolean HasMoreResults member, a ResultContinuationToken ContinuationToken member, and methods that accept and maintain these to support paging operations.
I don’t see how to obtain a Continuation from a DataServiceQuery. I don’t see that the ManagementServiceReference.ManagementService exposed by Azure supports a paged list of service identities, even though the service is, apparently, paging the results it sends me. Can you point me to the right article that will show me how the DataServiceQuery can be treated in a way that I get a Continuation back?

Using the management service sample project that's available here, what you want would look something like this:
ManagementService mgmtSvc = ManagementServiceHelper.CreateManagementServiceClient();
List<ServiceIdentity> serviceIdentities = new List<ServiceIdentity>();
// Get the first page
var queryResponse = mgmtSvc.ServiceIdentities.Execute();
serviceIdentities.AddRange( queryResponse.ToList() );
// Get the rest
while ( null != ( (QueryOperationResponse)queryResponse ).GetContinuation() )
{
DataServiceQueryContinuation<ServiceIdentity> continuation =
( (QueryOperationResponse<ServiceIdentity>)queryResponse ).GetContinuation();
queryResponse = mgmtSvc.Execute( continuation );
serviceIdentities.AddRange( queryResponse.ToList() );
}

Related

Controller return type and httpStatus best practice and production/consumption on method in REST WS

I commence in REST and I have some questions:
What type must the controller return? Typically, I'm asking if my Rest #Controller must return Item object as it is or encapsulate it in ResponseEntity in order to specify http-status-code.
What http status code to use in a GET method on a particular item ("/items/2") if the given item does not exists: HttpMediaStatus.OK(200) and null return or HttpStatus.NO_CONTENT(204) and null return ?
Second part: I saw it was possible to specify #Produces and #Consumes on WS method but what the use of that? My application and my methods work so, why specify MediaType.APPLICATION_JSON_VALUE? Doesn't Spring/SpringBoot automatically convert Item or ResponseEntity into json?
Context: using Spring Boot, hibernate, REST webservice.
Thank you.
Many questions in one, I'll provide short answers with a bunch of link to relevant articles and the reference documentation.
What type must the controller return?
Depends on your annotation and the RESTful-ness of your service. There are three annotations you can use for controllers: #Controller, #RestController and #RepositoryRestController.
Controller is the base annotation to mark your class as a controller. The return type of the controller endpoint methods can be many things, I invite you to read this dedicated post to get a grasp of it.
When developing a pure-REST service, you will focus on using RestController and RepositoryRestController.
RestControlleris Controller + ResponseBody. It binds the return value of the endpoint method to the web response body:
#RestController
public ItemController {
#RequestMapping("/items/{id}")
public Item getItem(#PathVariable("id") String id) {
Item item = ...
return item;
}
}
With this, when you hit http:/.../api/items/foo, Spring does its magic, automatically converting the item to a ResponseEntity with a relevant 40X status code and some default HTTP headers.
At some point, you will need more control over the status code and headers, while still benefiting from Spring Data REST's settings. That's when you will use RepositoryRestController with a ResponseEntity<Item> as return type, see the example the Spring Data REST reference.
What http status code to use in a GET method on a particular item if the given item does not exists?
Bluntly said: use HttpStatus.NOT_FOUND. You're looking for a resource that does not exist, there's something wrong.
That being said, it is completely up to you to decide how to handle missing resources in your project. If your workflow justifies it, a missing resource could be something completely acceptable that indeed returns a 20X response, though you may expect users of your API to get confused if you haven't warned them or provided some documentation (we are creatures of habits and conventions). But I'd still start with a 404 status code.
(...) #Produces and #Consumes on WS method but what the use of that? My application and my methods work so, why specify MediaType.APPLICATION_JSON_VALUE? Doesn't Spring/SpringBoot automatically convert Item or ResponseEntity into json?
#Consumes and #Produces are respectively matched against content-type and accept headers from the request. It's a mean of restricting the input accepted and the output provided by your endpoint method.
Since we're talking about a REST service, communications between clients of the API and the service are expected to be JSON-formatted. Thanks to Spring HATEOAS, the answer are actually formatted with the application/hal+json content-type.
In that scenario, you can indeed not bother with those two annotations. You will need them if you develop a service that accepts different content-types (application/text, application/json, application/xml...) and provides, for instance, HTML views to users of your website and JSON or XML response to automated clients of your service.
For real life examples:
Facebook provides the Graph API for applications to read to/write from its graph, while users happily (?) surf on web pages
Google does the same with the Google Maps API

How do you use the serviceNameFilter when calling QueryClient.GetServiceListAsync

I'm using Azure Service Fabric with stateless services. I have a list of services deployed under an application, and there's a naming convention used with those service names. I'd like to get a list of services that match a filter expression.
Here is a link to a screenshot of my service fabric explorer. I don't have the reputation points to post an image.
Service Fabric Explorer screenshot
In this example, the name of my application is SFApp1, and the name of my service is HelloWorldStateless. I'd like to query the service fabric cluster to locate all services with the name "HelloWorldSt*" (under the SFApp1 application of course).
I know I can query to find all services with the application name "fabric:/SFApp1", and it'll return all services under that application. This overload of GetServiceListAsync takes just an application URI.
FabricClient client = new FabricClient();
ServiceList serviceList = client.QueryManager.GetServiceListAsync(new Uri("fabric:/SFApp1")).Result;
I also know I can query to find a specific service. This overload takes an application URI AND a service URI and will return a single-item list.
FabricClient client = new FabricClient();
ServiceList serviceList = client.QueryManager.GetServiceListAsync(new Uri("fabric:/SFApp1"), new Uri("fabric:/SFApp1/HelloWorldStateless")).Result;
What I'm trying to find out is if there's any way to do something like a wildcard search.
FabricClient client = new FabricClient();
ServiceList serviceList = client.QueryManager.GetServiceListAsync(new Uri("fabric:/SFApp1"), new Uri("fabric:/SFApp1/HelloWorldSt*")).Result;
The name of the parameter where the service name is specified is serviceNameFilter, and the method returns a list. I'm wondering why they would return a list for this overload if the result was always going to be a single-item list. Also, the parameter name "serviceNameFilter" suggests (to me at least) that there's the ability to supply some kind of expression to narrow down your list.
Here's what I've tried already. I've tried the code above, where I chop off a few characters and put an asterisk. I've tried without the asterisk to see if it was a substring match. I've tried SQL-style, with a percent symbol. I've tried a question mark. All of those attempts returned an empty list.
My current workaround is just to ask for all services under that application, and I'll filter them on the client code end with a linq expression. That'll work, but I worry about performance if my list of services gets really big.
Would be nice if I could inspect the source code to answer this myself.
Is there a way to do what I'm trying to do, or am I just misinterpreting what "serviceNameFilter" means, and it just means you have to put the entire service URI that you're looking for?
Thanks for any help you can provide!
Unfortunately that API parameter is terribly named. It's not really a filter at all, it's just the name of the service (since there's no other query that just returns one service, this is how you "filter" from all the services in an application down to just one in particular).
The nearest thing to what you're looking for is EnumerateSubnames. It's not a wildcard search, but you can get all the names that exist "underneath" a given name (for example, all of the service names that exist within an application, or all names with some specific prefix). Depending on the structure of how you create your service names this could work for you.
// System.Fabric.FabricClient.PropertyManagementClient
public Task<NameEnumerationResult> EnumerateSubNamesAsync(Uri name, NameEnumerationResult previousResult, bool recursive)
For example: Presume the following names exist in the cluster:
fabric:/SomeApplication/Zone1/Service1
fabric:/SomeApplication/Zone1/Service2
fabric:/SomeApplication/Zone2/Service1
Note that in this case the application would have been created with the name "fabric:/SomeApplication" and then the services with the detailed names above incorporating the "Zone" segment.
If you now EnumerateSubnames("fabric:/SomeApplication/Zone1", null, true) you'd get back a result that gave you the full names that matched (1 & 2 above).

Why does one HTTP GET request retrieve the required data and another retrieve []

I'm currently working on ng-admin.
I'm having a problem retrieving user data from my REST API (connected to a MongoDB) and displaying it.
I have identified the problem as the following:
When I enter http://localhost:3000/users into my browser, I get a list of all users in my database.
When I enter http://localhost:3000/users?_page=1&_perPage=30&_sortDir=DESC&_sortField=id,
I get [] as a result.
I am quite new to this, I used both my browser and the POSTMAN Chrome extension to test this and get the same result.
http://localhost:3000/users_end=30&_order=DESC&_sort=id&_start=0
This (/users_end) is a different request than /users.
It should be:
http://localhost:3000/users?end=30&_order=DESC&_sort=id&_start=0
Or, by looking at the other parameters:
http://localhost:3000/users?_end=30&_order=DESC&_sort=id&_start=0
with end or _end being the first parameter (mark the ?).
Update (it is ? and before the _, I have edited.):
If adding parameters to the request returns an empty list, try adding only one at a time to narrow down the problem (there's probably an error in the usage of those parameters - are you sure you need those underscores?).
Your REST API must have a way to handle pagination, sorting, and filtering. But ng-admin cannot determine exactly how, because REST is a style and not a standard. So ng-admin makes assumptions about how your API does that by default, that's why it adds these _end and _sort query parameters.
In order to transform these parameters into those that your API understands, you'll have to add an interceptor. This is all thoroughly explained in the ng-admin documentation: http://ng-admin-book.marmelab.com/doc/API-mapping.html

Restful API for Templating

I am struggling with a design aspect of my restful api for templating collections of resources.
The endpoint calls for a json with the name to a particular template and a collections of tokens. The API will then create entries into numerous tables and use the tokens where appropriate.
A very simple example is:
*{
'template': 'DeviceTemplate'
'tokens': [
'customer': 1234,
'serial_number': '12312RF3242a',
'ip_address': '1.1.1.1'
]
}*
This creates a new device for the customer with that ip address along with several other objects, for instance interfaces, device users etc etc. I use the tokens in various places where needed.
I'm not sure how to make this endpoint restful.
The endpoint for /device is already taken if you want to create this resource individually. The endpoint I need is for creating everything via the template.
I want to reserve the POST /template endpoint for creating the actual template itself and not for implementing it with the tokens to create the various objects.
I want to know how to call the endpoint without using a verbs.
I also want to know if its a good idea to structure a POST with a nested JSON.
I'd suggest that you create an action on the template object itself. So right now if you do /templates/<id> you are given an object. You should include in that object a url endpoint for instantiating an instance of that template. Github follows a scheme that I like a lot [1] where within an object there will be a key pointing to another url with a suffix _url. So for instance, your response could be something like:
{
"template": "DeviceTemplate",
"id": "127",
...
"create_url": "https://yourdomain.com/templates/127/create",
...
}
Then this way you treat a POST to that endpoint the same as if this template (DeviceTemplate) was its own resource.
The way to conceptualize this is you're calling a method on an object instead of calling a function.
[1] - For example https://developer.github.com/v3/#failed-login-limit

Sharepoint URL to reference a lookup

I have two SharePoint lists used for Support case management. The first list contains Case Numbers and information about the case. The second list contains exhibits that support the case itself.
We have a convention that the Case Number is a String supplied by the worker, ex 20150205-001. When the exhibits are joined to the Case it is through a Lookup. I want the Exhibit ID, a String, to be of the form Case Number + _[A-Z] -- and be auto-assigned.
I want to use a Workflow (MS Sharepoint Designer 2013) to assign the Exhibit ID. The problem I face is that I cannot get the actual Case Number from the Lookup. The closest I have gotten so far is to get the ID (1, 2, etc) but not the actual String value represented.
Tried working with the following URL:
http://[mySiteURL]/_api/web/lists/getbytitle([listName])/items?$select=Title,Case/Id&$expand=Case/Id&$filter=Case/Id%20eq%2020150205%45001
substituted ascii: $filter=Case/ID eq 20150205-001
without the filter I get all list items (understandably) but the filter does not work properly because the ID is not the actual lookup value.
This is a SPD 2013 limitation. You have to use a web service call from within Designer to get the specifics of a lookup column from SharePoint. You make a REST call ad then parse the JSON response for the specific data from the lookup column. It gives you access to all of the columns from the list item that you looked up:
Build {...} Dictionary (Output to Variable: requestHeader )
Call [%Workflow Context:Current Site URL%]... HTTP web service with Variable: Request (ResponseContent to Variable: PoleIDData |ResponseHeaders to Variable: dictionary |ResponseStatusCode to Variable: responseCode )
Get d/Pole_x0020_ID from Variable: PoleIDData (Output to Variable: PoleID )
Set Name to Variable: PoleID
Your actual web service call will be formatted like this:
[%Workflow Context:Current Site URL%]/_api/web/lists/GetByTitle('List Name')/Items([%Current Item:ID%])/LookupColumnNameOnOtherList
Sorry for the formatting, I would post a screenshot but I cannot.
This article is good for showing you some of the other specifics about formatting your HTTP Request, especially the Request Headers which must be setup right.
http://www.fiechter.eu/Blog/Post/37/SharePoint-2013--HTTP-Web-Service-Action---Use-Managed-Metadata-as-Text-in-Workflow