AWS Workbench Properties Editor

The properties editor define the characteristics of the AWS Service.

For example a stack defined by properties as below

would generate the following code.

java.util.Map<java.lang.String, java.lang.String> mainStack_tags = new java.util.HashMap<java.lang.String, java.lang.String>();

		mainStack_tags.put("name", "demoStack");
		mainStack_tags.put("env", "primary");
		mainStack_tags.put("region", "us-east-1");

		mainStack = software.amazon.awscdk.core.Stack.Builder.create(app1, "MAINSTACK")
				.description("A Demo stack for ArchOps Demo").env(mainStackEnv).stackName("mainStack")
				.tags(mainStack_tags).terminationProtection(true).build();

Understanding properties editor is critical to use this tool effectively.

Properties of AWS Services are modelled based on Builder pattern .

For example this is the Builder for Stack. The names of the methods in the Builder become the property names in the Property editor.

Mandatory properties

• For App object, projectName, packageName, mainClassName, varName and identifier are mandatory properties.
• For Block and Sub Block, label is mandatory. Block has one more property called canDeploy. Until the value of canDeploy is true, Block content is in draft state and the corresponding code will not be exported. Neither the elements from the Block can be referenced in other blocks.
• For Stack and all other AWS Service Components, varName and identifier are mandatory properties.

Property types

• Properties can be of type String, Number,Boolean,Enum,Reference,List and Map
• To know the expected value for the property, hover on the ? next to the property name. The information is available as a tooltip on the ? symbol. When the expected value is a Reference , the complete class name is displayed in the tooltip. More information on the class is available at AWS CDK Javadocs

• For String, Number and Reference, a Textbox is provided to enter the values

• A Boolean is represented by Checkbox .

• Enum are represented by Radio Buttons

• For List and Map , a List Box is provided.

  

Clicking Add value button pops up a dialog box prompting to enter the list or map value

List Item Dialog:

Map Item Dialog

Using References

There are 3 ways that you can access other objects and classes in Direct variable access , Access a method of a variable and Invoke a static method on ca class

Direct variable access

Every AWS Service instance has a varName property. This is the reference to the service which can be used in other AWS Services where the service instance needs to be referenced. For example; if there is a instance of Environment object mainStackEnv is being reference by Stack instance mainStack

Environment Properties:

Stack Properties:

The generated code would be

        mainStackEnv = (new software.amazon.awscdk.core.Environment.Builder()).region("us-east-1").build();

		java.util.Map<java.lang.String, java.lang.String> mainStack_tags = new java.util.HashMap<java.lang.String, java.lang.String>();

		mainStack_tags.put("name", "demoStack");
		mainStack_tags.put("env", "primary");
		mainStack_tags.put("region", "us-east-1");

		mainStack = software.amazon.awscdk.core.Stack.Builder.create(app1, "MAINSTACK")
				.description("A Demo stack for ArchOps Demo").env(mainStackEnv).stackName("mainStack")
				.tags(mainStack_tags).terminationProtection(true).build();

Access an instance method of a variable (surround by ~ )

At times you would need to access a method of a service instance. For example Subnet Builder needs access to vpcId which can be accessed thru getVpcId() method of Vpc service.

To reference this method of a variable in a property, we can surround the expression with ~. See example below.

VPC Properties

Subnet Properties

The generated code would be

default_vpc = software.amazon.awscdk.services.ec2.Vpc.Builder.create(mainStack, "DEFAULT_VPC")
				.cidr("10.0. 0.0/16").enableDnsHostnames(true).enableDnsSupport(true).maxAzs(2).natGateways(1)
				.vpnGateway(true).build();

subnetUS1A = software.amazon.awscdk.services.ec2.Subnet.Builder.create(mainStack, "SUBNETUS1A")
				.availabilityZone("us-east-1a").cidrBlock("10.0. 0.0/16").vpcId(default_vpc.getVpcId())
				.mapPublicIpOnLaunch(true).build();

Access a static method of a class (surround by - )

Similar to accessing a method of a service instance, you may also be required to access the static methods of a class. For example; The instanceType method of AutoScalingGroup Builder needs to access the static method of() of InstanceType.

This can be acheived by surrounding the expressing with a -. See example below.

The generated code would be

autoScalingGroup16 = software.amazon.awscdk.services.autoscaling.AutoScalingGroup.Builder
				.create(mainStack, "AUTOSCALINGGROUP16").allowAllOutbound(true).maxCapacity(2)
				.replacingUpdateMinSuccessfulInstancesPercent(20).resourceSignalCount(4)
				.instanceType(InstanceType.of(InstanceClass.BURSTABLE2, InstanceSize.MEDIUM))
				.machineImage(new AmazonLinuxImage()).vpc(default_vpc).build();

About importExistingResource

All AWS Service Components have a property called importExistingResource . This property is used to import existing resource. For example fromLookup() method in VPC. More information on importing existing resource is described here.

About additionalCode

This property is not used for now. Values in this field have no effect on the generated code.

A note on cyclic dependencies

AWS Workbench determines the order of service creation using topological sorting. The code generator would throw an error if it detects a cycle of dependencies. eg: A VPC referencing a Subnet and a Subnet referencing the VPC. In such cases, use reference in those services which are dependent on the other (Reference in Subnet instead of VPC) .