Overview

In this module, we'll cover how to enable persisted queries and safelisting to ensure only approved operations are executed by the router.

Persisted queries and safelisting

We want to lock down what type of queries can be executed against our graph so that only pre-approved queries can be run. To enable this, we need to turn on persisted queries with safelisting. Safelisting will allow us to provide a predefined list of allowed queries and then block any queries that are not on that list.

The current state

1. Jump over to Explorer in Studio and build a few queries. Use some of the examples we had in the previous modules.

2. As long as the query is valid and has the correct input parameters, we should get data back. This is because our graph currently accepts any query.

Now, let's enable persisted queries with safelisting and observe how this behavior changes.

Configure the router

1. Open up the router/router.yaml file in GitHub and click the ✏️ pencil icon in the upper right to edit the file.

2. Add the following configuration:

   router/router.yaml

   preview_persisted_queries:
     enabled: true
     safelist:
       enabled: true
       require_id: false
   apq:
     enabled: false

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   Let's go through what these changes to router.yaml are doing. The first few lines are fairly straight-forward: we enable persisted queries and then we enable safelisting.

   require_id is a property that lets us decide if we need to send the query with the hash ID used in the persisted queries list. The GraphOS Router will not accept any GraphQL request that is sent with a body. In this case, that option is disabled.

   The final piece is to disable automatic persisted queries (apq). You can learn more about this feature in the Apollo documentation.

3. Commit your changes.

   https://github.com

   

Make sure the CI/CD pipeline runs successfully before continuing on.

Configure persisted queries in the graph

We've got a few more configurations to do in the graph itself.

1. Navigate to Studio and open up ➡️ Settings view ➡️ This Graph ➡️ Configure Persisted Queries.

   https://studio.apollographql.com

   

2. We can see that we already have a persisted query list loaded. To link that to our current variant, click on the dropdown menu on the right-hand side and select the "Link and Unlink Variants" option.

   https://studio.apollographql.com

   

3. In the Link and Unlink Variants modal, select to link the "current" variant and hit Save.

   https://studio.apollographql.com

   

4. Now, back on the PQ page, it should show that the current variant is linked.

5. Click on the "pq_list" to explore the list.

   https://studio.apollographql.com

   

   We can see that our persisted query list is quite small; we only have one operation for users.

Check your work

Let's test out some queries to see how our router responds.

1. Head to Explorer to build out a simple query of your choice, and try to run that query. Your request should be denied, with an error similar to this:

   {
     "errors": [
       {
         "message": "The operation body was not found in the persisted query safelist",
         "extensions": {
           "code": "QUERY_NOT_IN_SAFELIST"
         }
       }
     ]
   }

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   We can see that random queries not on our PQ list are now denied!

2. Now let's run a query that is in our PQ list. Copy the Users operation and run it:

   A query configured in our safelist

   query Users {
     users {
       firstName
       lastName
       email
       activeCart {
         items {
           colorway
           price
           size
           id
         }
       }
     }
   }

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   https://studio.apollographql.com

   

   This query should succeed, and we can see that we have now locked down our graph so only pre-approved queries can be executed.

Reverting changes

For demo and testing purposes, to revert those changes, simply disable safelisting or remove the safelisting configuration from the router.yaml file.

1. In GitHub, open the router/router.yaml file and click the ✏️ pencil icon in the upper right corner.

2. Remove the persisted queries safelisting option or set the enabled flag for safelist to false.

   router/router.yaml

   persisted_queries:
     enabled: true
     safelist:
       enabled: false
       require_id: false
   apq:
     enabled: false

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Up next

In this module, we've covered how we can protect our graph from unapproved queries using persisted queries and safelisting.

Now that we feel comfortable adding a layer of security to our graph, it's time to enable authentication and authorization.