Guide: Apollo Federation Project

Subgraphs

For this guide, we are going to use the following Subgraphs:

Here’s the GraphQL schema (SDL) for every subgraph we are going to publish to Hive:

enum CURRENCY_CODE {
  USD
}
 
type Department {
  category: ProductCategory
  url: String
}
 
type Money {
  amount: Float
  currencyCode: CURRENCY_CODE
}
 
type Price {
  cost: Money
  deal: Float
  dealSavings: Money
}
 
type Product @key(fields: "id") {
  id: ID!
  title: String
  url: String
  description: String
  price: Price
  salesRank(category: ProductCategory = ALL): Int
  salesRankOverall: Int
  salesRankInCategory: Int
  category: ProductCategory
  images(size: Int = 1000): [String]
  primaryImage(size: Int = 1000): String
}
 
enum ProductCategory {
  ALL
  GIFT_CARDS
  ELECTRONICS
  CAMERA_N_PHOTO
  VIDEO_GAMES
  BOOKS
  CLOTHING
}
 
extend type Query {
  bestSellers(category: ProductCategory = ALL): [Product]
  categories: [Department]
  product(id: ID!): Product
}

Hive CLI Access Token

As you may have noticed, Hive has created three targets under your project: development, staging, and production. This guide will use the development target to explore the features Hive offers.

To begin, select the development target under your Hive project and then choose the Settings tab. On the Settings screen, you can manage your target’s settings and access tokens.

Under the Registry Access Tokens section, click the Generate new token button. Give your access token a name and select Schema Check & Push from the list of token presets:

Click on Generate Token button and you should get your CLI token created, with permissions to publish GraphQL schemas.

Make sure to copy your token and keep it safe. You won’t be able to see it again.

Publish your schemas

Now that you have your access token, and you have the base schema defined, you can publish your schema to the registry.

We’ll start with the Products subgraph.

Run the following command in your terminal, to publish your subgraphs/products.graphql to the registry (replace YOUR_TOKEN_HERE with the token you have just created):

hive schema:publish \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="products" \
  --url="http://fake.com/products/graphql" \
  --author "Me" \
  --commit "First" \
  subgraphs/products.graphql

If everything goes well, you should see the following output:

✔ Published initial schema.

If you’ll get to your target’s page on Hive dashboard, you should see that it was updated with the new schema you just published 🎉

Now, let’s publish the Reviews subgraph schema to Hive:

hive schema:publish \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="reviews" \
  --url="http://fake.com/reviews/graphql" \
  --author "Me" \
  --commit "Second" \
  subgraphs/reviews.graphql

If everything goes well, you should see the following output:

✔ Schema published

On your target’s Explorer page now, you’ll be able to see the schema of both subgraphs 🎉

Schema Checks

Hive can perform several checks on your schema before publishing it to the registry. You can use Hive CLI to run these check and find potential breaking changes, and potential composition issues when a Apollo Federation project is used.

To see how schema checks works, let’s make a small change to our schema. First, we’ll start with a non-breaking change - we’ll add a new field to the Review type under the Reviews subgraph:

extend type Product @key(fields: "id") {
  id: ID! @external
  reviews: [Review]
  reviewSummary: ReviewSummary
}
 
type Review @key(fields: "id") {
  id: ID!
  rating: Float
  content: String
  verified: Boolean # new field added
}
 
type ReviewSummary {
  totalReviews: Int
  averageRating: Float
}

Now, run the Hive CLI with the schema:check command and your modified subgraphs/reviews.graphql file:

hive schema:check \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="reviews" \
  subgraphs/reviews.graphql

You should see that Hive successfully detect the change you made, and exists with a 0 exit code, meaning that the schema is compatible, valid and has no breaking changes:

ℹ Detected 1 change
 
- Field verified was added to object type Review

Now, are going to try introduce a breaking change. To do that, we’ll rename an existing field in the GraphQL schema of the Reviews subgraph:

extend type Product @key(fields: "id") {
  id: ID! @external
  reviews: [Review]
  reviewSummary: ReviewSummary
}
 
type Review @key(fields: "id") {
  id: ID!
  averageRating: Float # renamed from "rating"
  content: String
}
 
type ReviewSummary {
  totalReviews: Int
  averageRating: Float
}

hive schema:check \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="reviews" \
  subgraphs/reviews.graphql

In that case, you’ll notice that Hive CLI exists with a 1 exit code, meaning that the schema has breaking changes, and it’s not compatible with the current schema in the registry:

✖ Detected 1 error
 
- Breaking Change: Field rating was removed from object type Review
 
ℹ Detected 2 changes
 
- Field rating was removed from object type Review
- Field averageRating was added to object type Review

In addition to detecting simple breaking changes, Hive is capable of detecting composability and compatibility issues across your subgraphs. To see how it works, let’s make a small change to our schema.

We are going to add a conflict to the Reviews service. We are going to add a new field (price) to the Product type, that conflicts with the Products type in the Products service.

extend type Product @key(fields: "id") {
  id: ID! @external
  reviews: [Review]
  reviewSummary: ReviewSummary
  price: Int # new field added
}
 
type Review @key(fields: "id") {
  id: ID!
  rating: Float
  content: String
}
 
type ReviewSummary {
  totalReviews: Int
  averageRating: Float
}

Run the Hive CLI with the schema:check command again and the modified subgraphs/reviews.graphql file:

hive schema:check \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="reviews" \
  subgraphs/reviews.graphql

And now you can see that the schema check process has failed, due to conflicts and inconsistencies between the schemas:

✖ Detected 2 errors
 
- Breaking Change: Field Product.price changed type from Price to Int
- [reviews] Product.price - Product.price already exists in the schema. It cannot also be defined in this type extension. If this is meant to be an external field, add the $(@external) directive. > Field
 
ℹ Detected 1 change
 
- Field Product.price changed type from Price to Int

Evolve your schema

Now that you have your schema published, you can evolve it over time. You can add new types, fields, and implement new capabilities for your consumers.

Let’s make a valid change in our schema and push it again to the registry:

extend type Product @key(fields: "id") {
  id: ID! @external
  reviews: [Review]
  reviewSummary: ReviewSummary
}
 
type Review @key(fields: "id") {
  id: ID!
  rating: Float
  content: String
  verified: Boolean # new field added
}
 
type ReviewSummary {
  totalReviews: Int
  averageRating: Float
}

And publish it to Hive:

hive schema:publish \
  --registry.accessToken YOUR_TOKEN_HERE \
  --service="reviews" \
  --url="http://fake.com/reviews/graphql" \
  --author "Me" \
  --commit "Third" \
  subgraphs/reviews.graphql

You should see now that Hive accepted your published schema and updated the registry:

✔ Schema published

It’s a good timing to check the History tab of your Hive target. You should see that a new schema is published now, and you can see the changes you made:

Fetch your Supergraph

Now that your GraphQL schema is stored in the Hive registry, you can access and fetch it through Hive’s CDN (Content Delivery Network).

The Hive Cloud service leverages the CloudFlare Global Network to deliver your GraphQL schema and schema metadata. This means that your schema will be available from the nearest location to your GraphQL gateway, with 100% uptime, regardless of Hive’s status. This ensures that everything required for your GraphQL API is always available, and reduces the risk of depending on Hive as a single point of failure. You can read more about Hive’s CDN here.

To get started with Hive’s CDN access, you’ll need to create a CDN token from your target’s Settings page. You’ll see a separate section for managing and creating CDN tokens, called CDN Access Token.

Click on Create new CDN Token to create a new CDN token. Describe your token with an alias, and click Create. Please store this access token securely. You will not be able to see it again.

To use your access token, go to your target’s page on Hive’s dashboard and click on the Connect to CDN button. You will see a screen with instructions on how to obtain different types of artifacts from the CDN. For this guide, you can pick the Apollo Federation Supergraph artifact.

Copy the URL and let’s try to fetch your schema using curl (replace YOUR_HIVE_CDN_TOKEN with your CDN token, and CDN_ENDPOINT_HERE with the endpoint you copied from Hive’s dashboard):

curl -L -H "X-Hive-CDN-Key: YOUR_HIVE_CDN_TOKEN" CDN_ENDPOINT_HERE

You should see that Hive CDN returns the complete Supergraph as an output for that command.

GraphQL Gateway

The next step is to use real subgraphs and a GraphQL gateway that routes GraphQL requests to your subgraphs.

For an Apollo Federation gateway you may use Apollo Gateway (JS) or Apollo Router (Rust) depending on your needs. You can use the following guides to deploy a gateway based on your technical preference:

Next Steps

Now that you use the basic functionality of Hive as a schema registry, we recommend following other powerful features of Hive:

• External Schema Compostion for Apollo Federation v2
• Usage Reporting and Monintoring
• Conditional Breaking Changes
• Alerts and Notifications
• CI/CD Integration
• Schema Policies