Creating Microservices from Fiorano eStudio

Fiorano provides a complete GUI based approach to define, build and deploy components from Fiorano Studio. In this section, the different wizard steps of the configuration wizard are explained.

Creating a new Microservice

To create a new microservice, go to Tools > Create Service Component to open the Micro Service Creation Wizard (Figure 2).

Figure 1: Menu containing Create Service Component action

All details related to the creation of a new microservice must be specified in this wizard. The various steps involved in the creation of microservice are illustrated below.

Microservice Location

This is the location where the component source code and other required files that are generated need to be saved.

• Parent Directory: Provide the absolute path where the folder has to be saved, for example, D:\New\Services

• Destination Directory: Provide the name of the folder to be saved under the above location.

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  Provide a new name for the folder. If the folder name already exists, then the wizard does not proceed to the next panel.

A new folder with the name specified for the Destination Directory will be created within the Parent Directory specified, which is the final location for the microservice files generated by the wizard. 

Figure 2: Service Location Panel in the Microservice creation wizard

Basic Details

This panel allows specifying the type of component and providing identification details of the component to be used within tools.

• Service Guid: Provide a name that the system can uniquely identify the microservice.
• Name: Display name for the component. It is typically different from the Service Guid and is the name displayed by the Fiorano eStudio for this Component.
• Version: This value will be pre-populated, but can be edited if required.
  
  
  Figure 3: Basic Details panel

• Category: The components that are registered in the Enterprise Server are categorized under different categories for easier maintenance as seen under the Micro Service Palette. In the Category field, a new Category name can be provided for the component or an existing Category can be selected from the available categories by clicking the button next to the property. Existing Categories can be viewed by clicking the ellipsis button that is displayed next to the Category field. On clicking ellipsis, the Category Selection dialog box is displayed as shown in the figure below. Multiple Categories can also be selected in the dialog box. The components are shown grouped under the category they belong to in tools. The figure below illustrates the organization of categories in Fiorano eStudio
  
  
  Figure 4: Category Selection dialog box
  
  
• Generate Source: Used to generate sources for various languages. The option Assemble From Binary is used to create System Libraries. 
• Source Language: By default, the language option is set to 'Java (JMS)'. The other language options available are:
  • Java (EDBC)
  • Java (JCA)
  • C
  • CPP
  • CSharp
    
    
  
  Figure 5: Source Language options
   
• is CCP enabled

• • If enabled, the component listens, understands and responds to control events from the Peer Server. It allows components launched as a separate process to clean up after stopping.

  • If disabled, the component does not handle control events from the Peer Server. The Peer Server will not send any control event to the component. If a component is launched in a separate process, it is issued a destroy command to stop the process and the component process will be killed instantly without any clean up.

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    This property will not be editable while editing the microservice from eStudio.

Ports Information

Data transfer among components is done over JMS. The components require data channels to receive the request and send the results. These data channels are called ports. Ports are MS destinations; either topics or queues. A component can have any number of input ports and output ports. The port details are configured in this panel.

A new port can be added by clicking the Add button. By default, the Port Type is 'Inport'. The Port Type as well as other port properties can be changed in the Wizard as required.

Figure 6: Ports Information

Port Schema Structure

If the component expects messages or sends out messages in XML format, the message should be compliant by specifying the DTD/XSD. It can be used as an assertion to make sure that the component receives the message in the format it expects or that it sends out the message in the format it is supposed to be sent. Fiorano eStudio checks for the format mismatches when the components are connected by a route while intimating them of the mismatch.

To provide schemas for the component ports, select the row of the respective port and click the Edit button. The Structure window gets displayed where the schemas and external schemas (if any) can be provided. Provide a valid schema by loading it from a file or copying/typing it. 

Figure 7: Schema Editing Window

Upon adding a valid schema in the text area, root element(s) will get auto-populated. Click the Root Element drop-down to select the root element; Finish button gets active. 

External Schema

To provide external schemas, right-click the Schema node and click the Add External Schema option. Follow the method used for adding schemas. Upon adding a valid schema, the root element name appears under the Schema node replacing the text 'External Schema'.

Figure 9: Adding External Schema

Generate XML Beans

This is an option to generate model objects based on the port schemas, that is, it generates Java classes from the XSDs that are provided for ports. The developer of a custom component can use these to access the input data and generate the output without bothering about input message parsing and output XML generation. The schemas for which this option is selected are stored in the schemasForXMLBeans folder in the component directory.

Resources

Any component created in general requires resources – third party libraries, Fiorano libraries or other files – at the time of component configuration or execution.

The resources required by the microservice (either during configuration time or runtime) can be added in this panel. Resources can be of any file type which is used by the component; there is no restriction on the type of file. Typically, resource files are of types – dll, zip, jar, so, exe.

The server makes a local copy of these files in the component repository (%FIORANO_HOME%\esb\fes\repository\components). So the same file added as a resource to two different components is copied into respective folders of both the components. When these components are launched in-memory of same peer server, resources are loaded into the respective class loaders of the components.

Resources can be added or removed using Add and Remove buttons respectively.

Figure 10: Resources panel

Dependencies

Resources and dependencies both serve the same purpose; providing the component with libraries or files required. However, they differ in the way these files or libraries are treated by Fiorano servers.

Dependencies are predefined. Every component or system library registered can be added as a dependency. The dependencies are referenced from the existing location and are not copied locally into the component folder.

• To Add: Select the dependency on the left side of the page and move it to the right side.
• To Remove: Select the dependency on the right side of the page and move to the left side.

Figure 11: Dependencies panel

Log Modules

Logging is a practice of writing out the messages indicating the state of the component, actions performed and any other related data. Logging is used for different purposes including:

• Notifying users of important actions/changes or problems (exceptions/errors) that occur during runtime
• Aiding developers in debugging the application
• Understanding the flow of data among different Method calls

For each of the above purpose, the data and the details that should be logged vary. Log levels help in meeting the needs of different users.

Figure 12: Log Modules Panel

Execution Information

This panel allows the user to specify the execution details of the component. A component, while executing, might require parameters to execute different request or details for handling different requests. There are two ways of passing this information to the component:

• By configuring the details in the Configuration Property Sheet of the panel (discussed in Component Configuration section)
• By defining the command line arguments that can be passed to the component during the launch of the component. These command line arguments are captured as runtime arguments in this panel.

Figure 13: Execution Information panel

Advanced Configuration

Non-Java properties

Selecting Non-Java Components such as C, CPP, CSharp as the Source Language property in the Basic Details panel (see Figure 2) leads to the Advanced Configuration panel with the following options: 

Supports Error Handling

• Enabled - Error port is shown when 'Show Error Ports' is selected
• Disabled - Error port is not shown even when 'Show Error Ports' is selected

Supports Failover to another Peer Server

• Enabled - When the Peer Server on which component is running goes down, the component keeps running on the next available Peer Server.
• Disabled - When the Peer Server on which component is running goes down, the component will not keep running on the next available Peer Server.

Supports Manual Launch

• Enabled - Component can be launched in 'Manual' mode
• Disabled - Component cannot be launched in 'Manual' mode

Figure 14: Advanced Configuration options for non-java components

Java properties

Selecting Java components such as Java (JMS), Java (EDBC) and Java (JCA) as the Source Language property in the Basic Details panel (see Figure 2) leads to the Advanced Configuration panel with the addition of following options other than the options described above: 

Supports Inmemory Launch

• Enabled - Component can be launched in 'In Memory' mode
• Disabled - Component cannot be launched in 'In Memory' mode

Generate Fiorano Installation as classpath variable

• Enabled - Assumes the Fiorano Installation path as the classpath variable
• Disabled - Fiorano Installation path would not be taken as the classpath variable by default

Figure 15: Advanced Configuration options for java components

Finishing Creation

Click the Finish button (see the figure above) to complete the process of creation; an Import Service dialog box appears. Click Yes to import the service files to the workspace and deploy the service right away.

Figure 16: Import Service dialog box to import to workspace

Importing Service on a later stage

Click No (see the image above) if you choose to open the project at a later point of time.

To import the service as a project into the workspace, perform the following actions:

1. Open Project Explorer view using any one of the following ways:
   1. Navigating through Window > Show View > Other > General > Project Explorer
   2. Click Show View as a Fast View  icon and navigate through Other > General > Project Explorer
2. In the Project Explorer  view, right-click and select Import. Import wizard pops up.
   
   
   Figure 18: Importing Service to workspace from Project Explorer
    
3. Expand General node, select Existing Projects into Workspace option and click Next.
   
   
   Figure 19: Navigating to existing projects
    
4. In the Import Projects panel, click Browse button to select the location where the service (s) was saved and select the projects added under Projects section. Click Finish.
   
   
   Figure 20: Browsing the location and selecting the projects to import

When the wizard is finished, sources are generated in src directory which would be placed under the folder specified in the Service Location page. It also creates necessary files to build and deploy the components.