GraphQL APIs¶

There are two GraphQL APIs in the server. One is a sub-endpoint of the Dynamic Client Registration endpoint to work with DCR clients. The other is the User Management GraphQL endpoint. It contains a schema to manage user accounts as graph data.

Using Access Tokens¶

In order to work with the GraphQL API an access token needs to be obtained. The authorization manager configured on the corresponding profile defines what the token needs to contain in order to gain access.

Most commonly it needs to contain a certain scope to pass the first authorization step, and if the groups authorization manager is used it also needs to contain the groups claim with a user group that matches one of the rules in the authorization manager.

Introspecting the Schema¶

The GraphQL schema can be obtained from the GraphQL endpoint. However it is required to provide an access token with at least read access to see the schema.

Most GraphQL tools allow you to configure the headers sent when accessing the endpoints.

Fig. 188 Example of adding an access token to GraphiQL

After this is done, the tool will be able to introspect the endpoint and the schema should become visible.

The schema exposes two top level types: Query and Mutation. The Query is used when reading data and Mutation when updating.

Fig. 189 Top level schema in GraphiQL

Fig. 190 Query schema in GraphiQL

Using Queries¶

There are two types of queries, singular and plural; to obtain a single account or multiple.

Listing 267 Querying for an account by username¶

query SingleAccount {
  accountByUserName(userName: "johndoe") {
    id
    userName
    emails {
      primary
      value
    }
  }
}

Listing 268 Response when querying for an account by username¶

{
  "data": {
    "accountByUserName": {
      "id": "b626d5d206f64165bb5c14a843545c9d",
      "userName": "johndoe",
      "emails": [
        {
          "primary": true,
          "value": "john.doe@example.com"
        }
      ]
    }
  }
}

When reading multiple accounts the system provides cursor based pagination to be able to get partial results. It’s also possible to filter the result.

Listing 269 Querying for multiple accounts¶

query AllAccounts{
  accounts(sorting: { sortBy: created, sortOrder: ASCENDING } ) {
    edges {
      node {
        id
        userName
        emails {
          value
          primary
        }
      }
    }
    pageInfo {
      endCursor
      hasNextPage
    }
    totalCount
  }
}

Listing 270 Response when querying multiple accounts¶

{
  "data": {
    "accounts": {
      "edges": [
        {
          "node": {
            "id": "1e99fb8210a944f1b6069a0cfe1c59c5",
            "userName": "bcryptUser",
            "emails": [
              {
                "value": "bcrypt.user@example.com",
                "primary": true
              }
            ]
          }
        },
      ]
      "pageInfo": {
        "endCursor": null,
        "hasNextPage": false
      },
      "totalCount": 13

The API loosely follows the definitions in relay.dev for pagination. Most concepts in the GraphQL APIs should be familiar to anyone experienced with GraphQL APIs.

Mutation Errors¶

When a GraphQL mutation fails due to data source constraints violation, a GraphQL error message is returned. The errors.extensions.field element contains the details about the attribute causing the violation.

Listing 271 Error when datasource already contains a user with provided userName attribute¶

{
    "errors": [
        {
            "message": "The username provided is already registered",
            "locations": [],
            "extensions": {
                "classification": "constraint-violation",
                "field": "userName"
            }
        }
    ]
}

DynamoDB limitations¶

Ad-hoc querying and sorting does not fit well into a database like DynamoDB, which is typically designed for a well-known set of access patterns. Due to this, the DynamoDB data source presents some limitations when used with the User Management and Dynamic Client Registration services.

User Management service limitations¶

The GraphQL accounts(...) query does not support the sorting attribute on DynamoDB. Sort is instead based on the provided filter and always uses ascending order:
- When filtering by userName, results are sorted by userName in ascending UTF-8 byte order.
- When filtering by email, results are sorted by email in ascending UTF-8 byte order.
The GraphQL accounts(...) query only supports the STARTS_WITH filter type for the filtering attribute, the ENDS_WITH filter type is not supported.
The GraphQL accounts(...) query supports search without the filtering attribute only when table scans are allowed. In which case, the results are not sorted.
No strong consistency is provided due to the eventually consistent nature of DynamoDB.

Dynamic Client Registration service limitations¶

No strong consistency is provided due to the eventually consistent nature of DynamoDB.
The GraphQL dynamicallyRegisteredClients(...) query supports search without the templateClient and userName attributes only when table scans are allowed. In which case, the results are not sorted.

GraphQL error for unsupported features¶

When a GraphQL query uses an unsupported feature, a GraphQL error message is returned. The errors.extensions attribute contains the details about the unsupported feature.

Listing 272 Error when filtering attribute is absent and table scans are disabled¶

{
    "errors": [
        {
            "message": "At least 1 filter key must be defined",
            "locations": [],
            "extensions": {
                "classification": "operation-not-supported",
                "not-supported-cause": "FILTERING_ABSENT"
            }
        }
    ]
}

The possible not-supported-cause extension attribute values are listed in the table below:

Cause	Message
FILTERING_ABSENT	At least 1 filter key must be defined
FILTERING_ENDS_WITH	Filtering operator `ends_with` is not supported
FILTERING_FILTER_TOO_SMALL	The filter value does not contain enough characters to perform a `starts_with` search
SORTING	Sorting is not supported