Posts tagged with 'or'

This is a repost that originally appeared on the Couchbase Blog: C# Tuples: New C# 7 language feature.

C# tuples are a new feature of C# 7. I’m going to show you the basics of how C# tuples work. I’m also going to mix in a little Couchbase to show tuples in action. However, if you don’t want to install Couchbase just to play around with tuples, don’t worry, you will still be able to follow along.

Note: If you’ve been using C# for a while, you might remember the Tuple Class that was introduced in .NET 4. That class still exists, but it is not the same thing as the new tuple feature of C#.

What are C# tuples?

A "tuple" is a name for a mathematical concept that is just a list of elements. In the LISP family of languages, coding is built almost entirely around the idea that everything is a list. C# once again borrows the kernel of an idea from the functional programming world and integrates it into a non-functional language. So, we get C# tuples (check out the original C# tuple proposal by Mads Torgersen for more details and background).

Remember anonymous types?

But, to make it simple, let’s consider something you may already be familiar with in C#, an anonymous type. To review, you can instantiate a new object without specifying a type:

var myObject = new { Foo = "bar", Baz = 123 };

Behind the scenes, there actually is a type that inherits from the base Object type, but generally speaking, we only deal with the object, not its type.

Additionally, I can’t return an anonymous type from a method, or pass an anonymous type as a parameter without losing the type information in the process.

private object GetAnonymousObject()
{
    return new {Foo = "bar", Baz = 123};
}

private void AnotherMethod()
{
    var obj = GetAnonymousObject();
    Console.WriteLine(obj.Foo); // compiler error :(
}

They are useful, certainly, but I generally refer to these as anonymous objects as I use them, for these reasons.

What’s this got to do with C# tuples?

I think of C# tuples as richer anonymous types. They are a way to create a "class" on the fly without actually defining a class. The syntax for tuples is to simply put parenthesis around a comma separated list of types and names. A tuple literal is just a comma separated list of literals also surrounded by parenthesis. For instance:

(string FirstName, string LastName) myTuple = ("Matt", "Groves");

Console.WriteLine(myTuple.FirstName); // no compiler error :)
Console.WriteLine(myTuple.LastName);  // no compiler error :)

Note: Right now I’m preferring PascalCase for tuple properties. I don’t know if that’s the official guideline or not, but it "feels" right to me.

C# tuples in action

I put tuples to work in a simple console app that interacts with Couchbase.

I created a BucketHelper class that is a very simple facade over the normal Couchbase IBucket. This class has two methods: one to get a document by key and return a tuple, and one to insert a tuple as a document.

public class BucketHelper
{
    private readonly IBucket _bucket;

    public BucketHelper(IBucket bucket)
    {
        _bucket = bucket;
    }

    public (string Key, T obj) GetTuple<T>(string key)
    {
        var doc = _bucket.Get<T>(key);
        return (doc.Id, doc.Value);
    }

    public void InsertTuple<T>((string Key, T obj) tuple)
    {
        _bucket.Insert(new Document<T>
        {
            Id = tuple.Key,
            Content = tuple.obj
        });
    }
}

To instantiate this helper, you just need to pass an IBucket into the constructor.

Tuple as a return type

You can then use the GetTuple method to get a document out of Couchbase as a tuple.

var bucketHelper = new BucketHelper(bucket);

(string key, Film film) fightClub = bucketHelper.GetTuple<Film>("film-001");

The tuple will consist of a string (the document key) and an object of whatever type you specify. The document content is JSON and will be serialized to a C# object by the .NET SDK.

Also, notice that the name of the tuple properties don’t have to match. I used obj in BucketHelper but I used film when I called GetTuple<Film>. The types do have to match, of course.

Tuple as a parameter type

I can also go the other way and pass a tuple as a parameter to InsertTuple.

string key = Guid.NewGuid().ToString();
Film randomFilm = GenerateRandomFilm();
bucketHelper.InsertTuple((key, randomFilm));

The GenerateRandomFilm method returns a Film object with some random-ish values (check out the GitHub source for details). A tuple of (string, Film) is passed to InsertTuple. The Couchbase .NET SDK takes it from there and inserts a document with the appropriate key/value.

Running the console app, you should get an output that looks something like this:

C# tuples sample console output

Note that the Couchbase .NET SDK at this time doesn’t have any direct tuple support, and it may not ever need it. This code is simply to help demonstrate C# tuples. I would not recommend using the BucketHelper as-is in production.

TUH-ple or TOO-ple?

I seem to remember my professor(s) pronouncing it as "TOO-ple", so that’s what I use. Like the hard-G / soft-G debate of "GIF", I’m sure there are those who think this debate is of the utmost importance and are convinced their pronunciation is the one true way. But, both are acceptable.

If you have questions about tuples, I’d be happy to help. You can also contact me at Twitter @mgroves or email me matthew.groves@couchbase.com.

If you have questions about the Couchbase .NET SDK that I used in this post, please ask away in the Couchbase .NET Forums. Also check out the Couchbase Developer Portal for more information on the .NET SDK and Couchbase in general.

This is a repost that originally appeared on the Couchbase Blog: ASP.NET with NoSQL Workshop.

I delivered an ASP.NET with NoSQL workshop at the recent Indy.Code() conference in Indianapolis. I had a lot of fun at this conference, and I recommend you go next year. If you were unable to attend, don’t worry, because I’ve got the next best thing for you: all the material that I used in my workshop.

ASP.NET Workshop in 4 parts

This workshop contained four main parts:

  • Install a NoSQL database (Couchbase Server)

  • Interact with Couchbase Server (using both the Web Console and the .NET (or .NET Core) SDK)

  • Create a RESTful API using ASP.NET (or ASP.NET Core) WebAPI

  • Consume the RESTful API with an Angular frontend

Try it yourself

If you’d like to try it yourself, the ASP.NET with NoSQL Workshop materials are available on GitHub. Each part of the workshop contains a PPT and PDF file for you to follow along. Also, the "completed" version of each workshop is available.

If you get stuck or have any questions, please ask away in the Couchbase .NET Forums. Also check out the Couchbase Developer Portal for more information on the .NET SDK and Couchbase in general.

You can also contact me at Twitter @mgroves.

Bill Wagner is writing .NET Core documentation.

Show Notes:

Bill Wagner is on Twitter

Want to be on the next episode? You can! All you need is the willingness to talk about something technical.

Theme music is "Crosscutting Concerns" by The Dirty Truckers, check out their music on Amazon or iTunes.

This is a repost that originally appeared on the Couchbase Blog: Authentication and Authorization with RBAC.

In March’s developer build, you can start to see some major changes to authentication and authorization within Role Based Access Control (RBAC) coming to Couchbase Server. These changes are a work in progress: the developer build is essentially a nightly build that gets released to the public. But there’s some good stuff in RBAC that’s worth getting excited about!

Go download the March 5.0.0 developer release of Couchbase Server today. Make sure to click the "Developer" tab to get the developer build (DB), and check it out. You still have time to give us some feedback before the official release.

Keep in mind that I’m writing this blog post on early builds, and some things may change in minor ways by the time you get the release, and some things may still be buggy.

Authentication and Authorization

Just a quick reminder of the difference between authentication and authorization:

  • Authentication is the process of identifying that a user is who they say they are.

  • Authorization is the process of making sure the user has permission to do what they are trying to do.

If you’ve used Couchbase before, you’re familiar with the login to what we sometimes call the "Admin Web Console".

Couchbase authentication screen

However, the Web Console is really not just for admins, it’s for developers too. But until now, you didn’t really have a lot of control built-in to Couchbase about who can log in and (more importantly) what they’re allowed to do.

So, I’d like to introduce you to Couchbase’s new first-class user feature.

Users

There’s still a full administrator user. This is the login that you create when you first install Couchbase. This is the user who is unrestricted, and can do anything, including creating new users. So, for instance, a full administrator can see the "Security" link in the navigation, while other users can’t.

Security link to manage authentication and authorization

Now, once on this security page, you can add, edit, and delete users.

A user can identify a person, but it can also identify some service or process. For instance, if you’re writing an ASP.NET application, you may want to create a user with a limited set of permissions called "web-service". Therefore, the credentials for that "user" would not be for a person, but for an ASP.NET application.

Next, try adding a new Couchbase user by clicking "+ Add User". I’m going to create a user called "fts_admin", with a name of "Full Text Search Admin", a password, and a single role: FTS Admin of the travel-sample bucket (FTS = Full Text Search).

Adding a new User

Here’s an animation of adding that user:

Add a new user with Couchbase authentication

Some notes about the above animation:

  • I selected "Couchbase" instead of "External". External is meant for LDAP integration. Note that "Couchbase" (internal authentication) will likely become the default in future releases.

  • FTS Admin gives the user permission to do everything with Full Text Searches: create, modify, delete, and execute them.

  • I granted FTS Admin only for the travel-sample bucket. If I selected "all", that would grant permission to all buckets, even ones created in the future.

  • Users with the FTS Searcher role only have access to execute searches, not modify or create them.

More on the difference between FTS Admin and FTS Searcher later.

Logging in as a new user

Now that this user is created, I can login as fts_admin. This user’s authentication is handled within Couchbase.

Login with Couchbase authentication

First, in the above animation, note that the fts_admin user has a much more limited set of options compared to the full admin user.

Next, it’s worth pointing out that users can reset their password:

Reset password

Creating an FTS index

Since I’ve already created an fts_admin user with the FTS Admin role, I’ll create another user called fts_searcher that only has the FTS Searcher role for the travel-sample bucket.

List of users

Using the REST API for FTS

I’m going to use the REST API to demonstrate that these users are limited by the roles I’ve given them. If you need a refresher on the REST API, you can refer to the documentation of the Full Text Search API. Also note that I’m using the REST API because there are some bugs in the UI as I’m writing this.

Let’s start by creating a new Full Text Search (FTS) index. I’ll do this via Postman, but you can use curl or Fiddler or whatever REST tool you prefer.

Create an FTS index

To create an index with the REST API, I need to make a PUT request to the /api/index/<indexname> endpoint.

  • First, I’ll create an index for the 'hotel' type in the travel-sample bucket, so I’ll PUT to /api/index/hotels

  • Also, credentials can be put in the URL to use basic authentication

  • Furthermore, the REST endpoints are available on port 8094

Finally, the URL for the PUT request should look something like this:

The body of the PUT is a big JSON object. Below is part of it. You can find the full version on GitHub to try for yourself.

{
  "type": "fulltext-index",
  "name": "hotels",
  "sourceType": "couchbase",
  "sourceName": "travel-sample",

// ... snip ...

}

Normally, you can create this via the UI instead of having to create JSON by hand. I’m not going to go into FTS in much detail in this post, because my goal is to demonstrate the new authentication and authorization features, not FTS itself.

Trying to create an index without authorization

Notice that I’m using fts_searcher as the user. I know that fts_searcher shouldn’t have permission to create indexes, so I would expect a 403. And that’s just what I get.

{
  "message": "Forbidden. User needs one of the following permissions",
  "permissions": [
    "cluster.bucket[travel-sample].fts!write"
  ]
}

So, while the authentication worked, that user doesn’t have the necessary authorization.

Creating an index with authorization

I’ll try again with fts_admin:

And assuming an index named 'hotels' doesn’t already exist, you’ll get a 200, and this in the body of response:

{
  "status": "ok"
}

Using the FTS index

Next, let’s use the REST API to search the index for the word 'breakfast'.

First, make a POST to the /api/index/hotels/query endpoint, again with the proper credentials and port number.

or

Both users should be able to execute a search using that index.

Next, in the body of the POST should be a simple JSON object. Again, you don’t normally have to create this by hand — your SDK of choice or the Web Console UI can do this for you.

{
  "explain": true,
  "fields": [
    "*"
  ],
  "highlight": {},
  "query": {
    "query": "breakfast"
  }
}

Finally, the result of this search request will be a large JSON response. Look within the "hits" sub-document for "fragments" to verify that the search worked. Here’s a snippet of my search for "breakfast". Again, the full result is on Github.

// ... snip ...

        "reviews.content": [
          "… to watch TV. <mark>Breakfast</mark> was served every morning along with a copy of the Times-Picayune. I took my <mark>breakfast</mark> downstairs in the patio, the coffee was very good. The continental <mark>breakfast</mark> is nothing to…"
        ]
      },

// ... snip ...

This is a preview, expect some bugs!

There are some bugs and some incomplete features.

  • I’ve shown FTS roles here on purpose. This is because the other roles are not yet fully formed. Please try them out, let us know what you think, but remember they are not in their final form. FTS is closest to ready.

  • I’ve seen some issues when logging in as a non-admin user causes the web console to behave badly. Because of this, I showed the REST example above instead of relying on the UI.

  • Finally, there might be other bugs that we don’t know about yet. Please let us know! You can file an issue in our JIRA system at issues.couchbase.com or submit a question on the Couchbase Forums. Or, contact me with a description of the issue. I would be happy to help you or submit the bug for you (my Couchbase handlers send me a cake pop when I submit a good bug).

If you have questions, the best way to contact me is either Twitter @mgroves or email me matthew.groves@couchbase.com.

Jeremy Miller is the creator of Storyteller.

This episode was recorded at CodeMash 2017 in a massive dining room, so the audio is a bit different than normal.

Show Notes:

Jeremy Miller is on Twitter

Want to be on the next episode? You can! All you need is the willingness to talk about something technical.

Theme music is "Crosscutting Concerns" by The Dirty Truckers, check out their music on Amazon or iTunes.

Matthew D. Groves

About the Author

Matthew D. Groves lives in Central Ohio. He works remotely, loves to code, and is a Microsoft MVP.

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