Mulesoft is a software company that provides an enterprise technology called Anypoint Platform. It can be used to implement, maintain and govern an increasing number of applications and systems.
In short, they aim to unify data to deliver and build connected APIs through API-led approach.
It was acquired by Salesforce for around $6.5 billion in a deal completed in March 2018.
More information on their website.
Overview
Thousands of enterprises use Anypoint Platform because it has an emphasis on consumption (feedback and usage metrics) as much as production (reusable assets).
Originally built as a single solution, the platform allows developers to design, develop, manage, integrate and deploy APIs.
Segments of it include :
Design center : Used for rapid development (designing, documenting and mocking)
Exchange : Used to collaborate, discover assets and get stakeholder feedback
Management center : Used to manage different aspects of the application
To support all of this, Mulesoft uses Mule Runtime as a dedicated server to deploy applications. These applications can be MuleSoft-hosted through CloudHub or customer-hosted in the cloud.
Applications can be created virtually through Flow Designer and Anypoint Studio or by writing XML based code.
Under the hood, all Mule applications are written in Java using the Spring framework.
If you’re interested in how to create web services using Spring, you can click here for one of our most popular articles on the subject.
The modern API, a core enabler of a new operating model is characterized by having :
Discoverable and accessible through a self-service
Productized and designed for ease of consumption
Easily managed for security, scalability and performance
This approach is called API-led connectivity.
Wrong way of doing API-led connectivityRight way of doing API-led connectivity
To achieve an unified application network of data, devices and APIs, there are some guidelines :
Emerges bottoms-up via self-service
Provides visibility, security and governability at every API node
Network is built for change
What is an API?
API stands for Application Programming Interface and it basically provides the info on how to communicate with implemented software components, defining the :
Operations (what to call)
Inputs (what to send)
Outputs (what to get back)
Underlying data types
There are basically two main types of web services or APIs :
SOAP : Traditional, more complex, based in XML
REST : Recent, simpler, based in the HTTP communication protocol
REST stands for Representation State Transfer and is defined by an architectural style where clients and servers exchange representations of resources.
The HTTP request indicates which operation should be performed on the object identified by the URL. Some examples of such operations :
GET /users
GET /users?country=Brazil
GET /users/3
POST /users with JSON/XML in HTTP body
DELETE /users/3
PUT /users/3 with JSON/XML in HTTP body
A RESTful web service can return data in many possible ways. A popular way is through JSON (JavaScript Object Notation) which is a lightweight data-interchange format that is readable to humans and supports collections and maps.
JSON data example
To design an API successfully, developers need to focus on performance of client applications such as Postman and ARC without forgetting about user experience.
Below is the API development cycle, specified by the Anypoint Platform as a good practice model :
Development cycle
Getting started with the Anypoint Platform
In the Design Center, a new application can be created by going through “Create new” -> “Create new application”.
First step when creating an application
After setting the name of the application (we’ve set ours to “CodeFiction App”) and clicking “Create”, a flow is generated and you’ll be redirected into the Flow Designer.
We’re able to assert that our application is up and running by checking the Logs tab located in the lower-right corner of the window.
If you’re unfamiliar with requests and endpoints testing, you can click here for more information on the subject of using Postman as a web client to verify endpoints.
Defining an API with RAML
Defining the specifications of an API such as resources, request methods and paths is not as complicated as one would think when working with the Anypoint Platform.
As with any project in the beginning :
Go through “Create new” -> “Create API specification”
Set the project name and click “Create Specification”
After creating our project, we start by defining our resources and its supported request methods in RAML, a YAML and JSON human-readable serialization format.
#%RAML 1.0
title: CodeFiction API
/users:
get:
queryParameters:
origin:
required: false
enum:
- BR
- US
- ES
post:
/{ID}:
get:
All resources are objects identified by the web service URL that you want to act upon using the HTTP method used for the request. They can be identified by a slash “/” before their name.
An important detail about editing RAML code is indentation, which indicates subordination and denotes the code which is a part of the function (or subordinate to the function call).
In the API console, by clicking the GET method we defined for the /users resource, information about the selected method shows up.
To test the path defined, we can click the “Try it” button. Of course, it won’t do anything now because we need to define a URL to call in the RAML definition.
Turn on the mocking service on top of the API console to activate a a mocking URL with the purpose of testing our defined method.
Mocking service button
A 200OK status code and an empty response should show up, indicating that everything is working as expected.
We can test our nested ID resource and our POST method the same way, resulting in a generic 200 status code response.
Adding a data type to an API resource
For any request, it’s important to specify the data types, descriptions and examples for the data in question.
To add a data type to our users resource, we need to create a file and specify a model to its properties and attributes.
Create a new file
Select “Data type” as category and set the file name
Add new data type file
We can now set the properties of our resource inside the newly created file.
Now to include these properties in the resource, we need to go back to our codefiction-api.raml file and update the code to specify our user type along with some http response configuration.
Any methods and params nested under a resource belong to and act upon that resource.
Adding an example data response to an API resource
To add an example response to our users resource, we need to create a new file in the same way we did before and fill it with user data.
Add new example data file
We can set the attributes of our example data inside the newly created file.
#%RAML 1.0 NamedExample
value:
-
ID: 1
name: John
lastname: Doe
origin: US
-
ID: 2
name: Carlos
lastname: Herrera
origin: ES
-
ID: 3
name: João
lastname: Silva
origin: BR
To include this data in the resource, we need to go back to our codefiction-api.raml file and update the code to include our output under the responses keyword with the appropriate indentation.
By sending a GET request to our users resource now with the mocking service turned on, we should get a 200 OK response with the example data displayed.
Example data displayed
We can do the same thing for our ID resource by creating an example file to handle single users requests.
#%RAML 1.0 NamedExample
value:
ID: 1
name: John
lastname: Doe
origin: US
The example file needs to be also included into our main api file under the correct resource with some additional configuration, the same way we did with the users resource example data.
It’s important to note that all documentation is auto-generated from the RAML file and displayed in the API console.
Endnotes
You can find the supporting source code available for this API in our GitHub repository here.
Feel free to leave a comment below if there’s something more you’d like to see covered in future articles regarding the Anypoint Platform or API development.
See you next time !
