Quick Start: Add Quota

Adding a Quota using Apigee-127

Adding a Quota using Volos.js is as simple as adding a few lines of YAML in your Swagger document!

• First, update your package.json file in your project to include the volos-quota-memory": module under

        "dependencies": {
             "express": "",
             "a127-magic": "",
             "volos-quota-memory": ""
        }

Note: You can also use a quota implementation that uses Redis or Apigee as its provider. More information here.

• Run, $ npm install.

• Execute $ a127 project edit to open up the Swagger editor.

• In the Swagger configuration file, under x-volos-resources, add the following to enable an in-memory quota provider named 'quota' that you refer to later:

        quota:     
            provider: volos-quota-memory
            options:
                timeUnit: minute
                interval: 1
                allow: 2 

• Finally, use x-volos-apply to apply this policy to the paths you want to enforce quotas on, referencing the resource you defined in the previous step:

        paths:     
            /hello:
                x-swagger-router-controller: hello_world
                x-volos-authorizations: {}
                x-volos-apply:
                    quota: {}

Now, try running the app as in the quickstart and try using the example curl command thrice:

        $ a127 project start
        $ curl http://localhost:10010/hello\?name\=Me 
        $ curl http://localhost:10010/hello\?name\=Me 
        $ curl http://localhost:10010/hello\?name\=Me 
          Error: exceeded quota<br> &nbsp; &nbsp;at...

The quota policy will only allow the first two requests per minute. From the third request onwards, you will get an error saying that the quota was exceeded.