Chapter 5. Trigger Your First Logic App in Azure

	Logic is the beginning of wisdom; not the end
	--Mr. Spock, Star Trek

Logic Apps are Platform as a Service (PaaS) offering from Microsoft that allows any technical user or developer to automate business process execution and workflow. With Logic Apps, you can connect devices, applications, and data residing on cloud or on premises.

This chapter introduces the following topics:

• Logic Apps help us understand why and when to use them

• We will be going over the key components and concepts of building a Logic App

• We will also understand the Logic App templates and how they help us quickly get started building our integration applications

An introduction to Logic App

Logic Apps are PaaS, which comes under Azure App Services, that provides the framework for developers to design simple or a complex business workflows without writing any code. The introduction of this service by Microsoft fills the void in Microsoft's enterprise cloud integration roadmap. As with the other App Services, it can dynamically scale up to meet your demand or scaled back when the demand eases off.

The main benefits of using this service is the simplicity of designing complex workflows using easy-to-understand design templates and implementing business process scenarios that would be difficult to develop using code and are time consuming. Connecting to disparate systems is more easily accomplished using the rich set of enterprise connectors and APIs. If you have constructed a generic Logic App connector, you also have the ability to monetize your Logic App in the Azure Marketplace.

Note

Here is the URL:  https://github.com/logicappsio for the community...

The comparison between BizTalk server and Logic Apps

BizTalk Server has been around since 2000, and there has been a number of new product releases since then. It is a very mature platform with excellent enterprise integration capabilities. On the other hand, Logic Apps is a fairly recent edition to the Azure PaaS list.

Logic apps can be likened to a BizTalk orchestration but has a much easier learning curve, and you don't have the deployment hassle of a full BizTalk solution. Although Logic Apps and BizTalk Server are not functionally equivalent, they do have some similarities.

Most of the enterprise features available in BizTalk are now available in Logic Apps using the Logic Apps Enterprise Integration Pack. This provides the following features and capabilities:

• XSLT-based maps

• XML schemas

• Trading Partners

• Trading Partner Agreements

• Certificates

The Enterprise Integration Pack is covered in more detail in Chapter 12, EAI / B2B Integration using Logic Apps.

Below is a comparison matrix between...

Why and when to use

Many enterprises now use a multitude of cloud-based SaaS services, and being able to integrate these services and resources can become complex. This is where the native capability of Logic Apps can help by providing connectors for most enterprise and social services and to orchestrate the business process flows graphically.

If your resources are all based in the cloud, then Logic Apps is a definite candidate to use as an integration engine.

When you have resources scattered in the cloud and on premise, then you may want to consider BizTalk as a choice for this type of hybrid integration along with Logic Apps. BizTalk 2016 include an adapter for Logic Apps. This Logic App adapter will be used to integrate Logic Apps and BizTalk sitting on premise. Using the BizTalk 2016 Logic App adapter on-premise, resources can directly talk to a multitude of SaaS platforms available on cloud. We will explain this in more details in the following chapters.

You can think of Logic Apps as...

Diagnosing Logic Apps

Logic App Diagnostics provides the capability to export the logs to either Event Hubs and to storage. Using Event Hubs, you can set up Streaming Analytics to gather any trends.

Another feature to help tracking messages through a workflow is the Client Tracking ID. This will allow you to correlate messages between actions and any nested workflows. The client can set the header property x-ms-client-tracking-id to a unique value that can be tracked. If no ID is provided by the client, the value is autopopulated.

Also, under the Logic app action blade as shown later, you have access to the input and output message links. From this, you can view the contents of the messages.

The two tools that should be part of your tool belt when performing end-to-end testing:

• Postman:  http://www.getpostman.com/ to construct HTTP request messages to your Logic Apps

• RequestBin:  http://requestb.in/ to capture the HTTP requests that will be sent to an API App from the Logic App by replacing...

Building your first Logic App

As this chapter is an introduction to Logic Apps, the sample solution will consist of a very basic workflow to get you familiar with creating a Logic App. Sunny Electricals wishes to store messages whenever one of their customers tweet about a product they have purchased from a store. The tweet message inserted into Azure SQL Database table will be used for organization internal product and service analysis purposes.

The First step is to create Azure SQL server and database and a table to hold tweet messages.

Create Azure SQL server, database, and table

Open the browser and log in to Azure portal:  https://portal.azure.com .

On Azure portal dashboard, click on the SQL databases option and click on Add to create new SQL database instance.

If the SQL databases option is not present on the Azure portal dashboard, you can find it by clicking to New , then click on Databases, and click on SQL Database.

Enter name in the Database name field followed by selecting valid...

Logic Apps using Visual Studio

In the earlier section, you have built a Logic App using the Azure portal. Now we will walk through developing Logic Apps using Visual Studio 2015. Logic Apps support a rich visual designer, and you can leverage the Visual Studio capability to build Logic App workflows. You can use Azure resource PowerShell scripts that ship with Logic Apps for automated deployment.

Visual Studio 2015 configuration steps for Logic App

To start working with Logic App using Visual Studio 2015, there are certain prerequisites that need to be installed and configured properly:

• Visual Studio 2015

• Latest Azure SDK (2.9.1 or greater)

• Access to Internet and valid Azure subscription

Once you have Visual Studio 2015 and Azure SDK 2.9.1 or higher, you can follow the steps later to configure your Logic App template within Visual Studio.

Run Visual Studio 2015 as administrator

On the Visual Studio designer surface, navigate to Tools | Extensions and Updates | Azure Logic Apps Tools for Visual...

Summary

In this chapter, we discussed how Logic Apps came about and their intentional uses in the world of integration. You learnt about the three main concepts of triggers, actions, and connectors when using Logic Apps. We compared development and integration features between Logic Apps and BizTalk server and discussed different integration scenarios. We looked at some tools to help test and diagnose Logic Apps and built our very first Logic App using both the Azure portal and Visual Studio 2015.

In the next chapter, we will take a deep dive into Logic App connectors and develop our very own adaptor.