rover dev

Follow-along: Setting up rover dev

Exploring files

1. Open up the workshop project repo. Subgraphs are split up into two folders: subgraph-listings and subgraph-reviews.

2. Open up the config file for the router: router-config.yaml

   router-config.yaml

   supergraph:
     listen: 127.0.0.1:4000
   include_subgraph_errors:
     all: true
   telemetry:
     instrumentation:
       spans:
       mode: spec_compliant

3. Open up the config file for the supergraph: supergraph.yaml

   supergraph.yaml

   federation_version: =2.7.0
   subgraphs:
     listings:
       routing_url: http://localhost:4001/
       schema:
         file: ./subgraph-listings/listings.graphql
     reviews:
       routing_url: http://localhost:4002/
       schema:
         file: ./subgraph-reviews/reviews.graphql

Run rover dev

First, we'll get our subgraph servers running. Then, we'll run rover dev. We'll have three terminal windows: one for each subgraph server process, and another for the rover dev process.

We recommend renaming each terminal window to better represent what process it's running.

Terminal window #1: subgraph-listings

1. In terminal window #1, navigate to the subgraph-listings directory.

2. If you haven't already, install dependencies.

   npm install

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3. Run npm run dev. It will reload the server every time we save our changes.

   npm run dev

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Terminal window #2: subgraph-reviews

1. In terminal window #2, navigate to the subgraph-reviews directory.

2. If you haven't already, install dependencies with npm install.

   npm install

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3. Run npm run dev. It will reload the server every time we save our changes.

   npm run dev

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Terminal window #3: rover dev

1. In terminal window #3, navigate to the root of your project repo.

2. Run the command below to start up rover dev:

   rover dev --supergraph-config supergraph.yaml --router-config router-config.yaml

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3. We'll see some output in the terminal, with a successful message and the endpoint to get to our router in http://localhost:4000.

   supergraph config loaded successfully
   ==> Watching router-config.yaml for changes
   warning: Do not run this command in production! It is intended for local development only.
   starting a session with the 'listings' subgraph
   ==> Watching ./subgraph-listings/listings.graphql for changes
   starting a session with the 'reviews' subgraph
   composing supergraph with Federation v2.7.0
   ==> your supergraph is running! head to http://localhost:4000 to query your supergraph
   successfully composed after adding the 'reviews' subgraph
   ==> Watching ./subgraph-reviews/reviews.graphql for changes

Sending a query with Apollo Sandbox

Apollo Sandbox lets us interact with our GraphQL API. With Explorer, we can build queries easily and send them to our GraphQL API.

1. Open up http://localhost:4000 where the router is running.

2. Run the example query pre-filled in the Explorer. Examine the response of IDs.

   query ExampleQuery {
     featuredListings {
       id
     }
     recentReviews {
       id
     }
   }

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3. Build a query with more fields by clicking on the + button beside each field. Run the query.

   query ExampleQuery {
     featuredListings {
       id
       title
       description
       costPerNight
     }
     recentReviews {
       id
       text
       rating
     }
   }

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4. Examine the response in table view.