property-set

Property Set

This sample shows how to easily define a Property Set and how to access data from it. This sample leverages the following policy:

• Assign Message policy to set the JSON response with values retrieved from a property set
• JavaScript policy to set HTTP response headers with values retrieved from the same property set

About Property Set

A property set is a custom collection of key/value pairs that store data. API proxies can retrieve this data when they execute.

Typically, you use property sets to store non-expiring data that shouldn't be hard-coded in your API proxy logic. You can access property set data anywhere in a proxy where you can access flow variables.

A common use case for property sets is to provide values that are associated with one environment or another. For example, you can create an environment-scoped property set with configuration values that are specific to proxies running in your test environment, and another set for your production environment.

How it works

Typically, you store property set values as name/value pairs in a file. Property set files are resource files of type properties.

Property set files support the same syntax as Java properties files; for example, they can contain Unicode values and can use # or ! characters as comment markers.

You must add the suffix .properties to a property file name. For example: myconfig.my_key.properties is allowed, but myconfig.my_key is not allowed.

The structure of a property set specification is: property_set_name.property_name.properties

The following example (used in this sample) shows a simple property set (myProps.properties) file that defines several properties:

# myProps.properties file
# General properties
foo=bar
baz=biff

# Messages/notes/warnings
message=This is a basic message.
note_message=This is an important message.
error_message=This is an error message.

# Keys
publickey=abc123
privatekey=splitwithsoundman

Implementation on Apigee

This sample is configured as a "no target API Proxy".

A Property Set (myProps.properties) is part of the property-set API Proxy resources.

We use the Assign Message policy to get values for two keys of the Property Set. This same policy is used to set a response presenting some key/value pairs in the form of a JSON content.

We use the JavaScript policy to get values for two keys of the Property Set. This same policy is used to set HTTP response headers using the accessed values.

Screencast

=======

Prerequisites

1. Provision Apigee X
2. Configure external access for API traffic to your Apigee X instance
3. Access to deploy proxies in Apigee
4. Make sure the following tools are available in your terminal's $PATH (Cloud Shell has these preconfigured)
   • gcloud SDK
   • unzip
   • curl
   • jq
   • npm

(QuickStart) Setup using CloudShell

Use the following GCP CloudShell tutorial, and follow the instructions.

Setup instructions

1. Clone the apigee-samples repo, and switch to the property-set directory

git clone https://github.com/GoogleCloudPlatform/apigee-samples.git
cd apigee-samples/property-set

2. Edit env.sh and configure the following variables:

• PROJECT the project where your Apigee organization is located
• APIGEE_HOST the externally reachable hostname of the Apigee environment group that contains APIGEE_ENV
• APIGEE_ENV the Apigee environment where the demo resources should be created

Now source the env.sh file

source ./env.sh

3. Deploy Apigee API proxies:

./deploy.sh

Example Requests

To manually test the proxy, make requests using curl:

curl -v https://$APIGEE_HOST/v1/samples/property-set

Use the debug tool inside Apigee to see how we access values in a property set, using the following syntax:

propertyset.<property_set_name>.<property_name>

AssignMessage policy to access a Property Set

You can use the AssignMessage policy to assign the value of property set key to a flow variable dynamically. In this sample, we create a JSON response, which contains values of the property set for two keys.

Here is the configuration of the AssignMessage policy:

<AssignMessage name="AM-SetResponseUsingPropertySet">
  <Set>
    <Payload contentType="application/json">
    {
      "foo":"{propertyset.myProps.foo}",
      "message":"{propertyset.myProps.message}"
    }
    </Payload>
  </Set>
  <IgnoreUnresolvedVariables>true</IgnoreUnresolvedVariables>
  <AssignTo createNew="false" transport="http" type="response"/>
</AssignMessage>

...and the JSON payload (response) that is created:

{
  "foo": "bar",
  "message": "This is a basic message."
}

Note: private information should be handled using encrypted KVMs (Key Value Maps) and not property sets.

JavaScript policy to access a Property Set

Access property set values anywhere in an API proxy where you can access flow variables: in policies, flows, JavaScript code, and so on.

For example, in a JavaScript policy, use the getVariable() method to get a value from a property set:

...
// access properties of the myProps.properties file
var baz = context.getVariable('propertyset.myProps.baz');
var note = context.getVariable('propertyset.myProps.note_message');
...

Cleanup

If you want to clean up the artifacts from this example in your Apigee Organization, first source your env.sh script, and then run

./clean-up.sh