Identity Providers

Apache Polaris supports authentication via external identity providers (IdPs) using OpenID Connect (OIDC) in addition to the internal authentication system. This feature enables flexible identity federation with enterprise IdPs and allows gradual migration or hybrid authentication strategies across realms in Polaris.

Authentication Types

Polaris supports three authentication modes:

  1. internal (Default)
    • Only Polaris internal authentication is used.
  2. external
    • Authenticates using external OIDC providers (via Quarkus OIDC).
    • Disables the internal token endpoint (returns HTTP 501).
  3. mixed
    • Tries internal authentication first; if this fails, it falls back to OIDC.

Authentication can be configured globally or per realm by setting the following properties:

# Global default 
polaris.authentication.type=internal
# Per-realm override 
polaris.authentication.realm1.type=external
polaris.authentication.realm2.type=mixed

Key Components

Authenticator

The Authenticator is a component responsible for resolving the principal and the principal roles, and for creating a PolarisPrincipal from the credentials provided by the authentication process. It is a central component and is invoked for all types of authentication.

The type property is used to define the Authenticator implementation. It is overridable per realm:

polaris.authentication.authenticator.type=default
polaris.authentication.realm1.authenticator.type=custom

Internal Authentication Configuration

Token Broker

The TokenBroker signs and verifies tokens to ensure that they can be validated and remain unaltered.

polaris.authentication.token-broker.type=rsa-key-pair
polaris.authentication.token-broker.max-token-generation=PT1H

Two types are available:

  • rsa-key-pair (recommended for production): Uses an RSA key pair for token signing and validation.
  • symmetric-key: Uses a shared secret for both operations; suitable for single-node deployments or testing.

The property polaris.authentication.token-broker.max-token-generation specifies the maximum validity duration of tokens issued by the internal TokenBroker.

  • Format: ISO-8601 duration (e.g., PT1H for 1 hour, PT30M for 30 minutes).
  • Default: PT1H.

Token Service

The Token Service and TokenServiceConfiguration (Quarkus) is responsible for issuing and validating tokens (e.g., bearer tokens) for authenticated principals when internal authentication is used. It works in coordination with the Authenticator and TokenBroker. The default implementation is default, and this must be configured when using internal authentication.

polaris.authentication.token-service.type=default

Role Mapping

When using internal authentication, token requests should include a scope parameter that specifies the roles to be activated for the principal. The scope parameter is a space-separated list of role names.

The default ActiveRolesProvider expects role names to be in the following format: PRINCIPAL_ROLE:<role name>.

For example, if the principal has the roles service_admin and catalog_admin and wants both activated, the scope parameter should look like this:

scope=PRINCIPAL_ROLE:service_admin PRINCIPAL_ROLE:catalog_admin

Here is an example of a full request to the Polaris token endpoint using internal authentication:

POST /api/catalog/v1/oauth/tokens HTTP/1.1
Host: polaris.example.com:8181
Content-Type: application/x-www-form-urlencoded

grant_type=client_credentials&client_id=root&client_secret=s3cr3t&scope=PRINCIPAL_ROLE%3Aservice_admin%20PRINCIPAL_ROLE%3Acatalog_admin

External Authentication Configuration

External authentication is configured via Quarkus OIDC and Polaris-specific OIDC extensions. The following settings are used to integrate with an identity provider and extract identity and role information from tokens.

OIDC Tenant Configuration

At least one OIDC tenant must be explicitly enabled. In Polaris, realms and OIDC tenants are distinct concepts. An OIDC tenant represents a specific identity provider configuration (e.g., quarkus.oidc.idp1). A realm is a logical partition within Polaris.

  • Multiple realms can share a single OIDC tenant.
  • Each realm can be associated with only one OIDC tenant.

Therefore, multi-realm deployments can share a common identity provider while still enforcing realm-level scoping. To configure the default tenant:

quarkus.oidc.tenant-enabled=true
quarkus.oidc.auth-server-url=https://auth.example.com/realms/polaris
quarkus.oidc.client-id=polaris

Alternatively, it is possible to use multiple named tenants. Each OIDC-named tenant is then configured with standard Quarkus settings:

quarkus.oidc.oidc-tenant1.auth-server-url=http://localhost:8080/realms/polaris
quarkus.oidc.oidc-tenant1.client-id=client1
quarkus.oidc.oidc-tenant1.application-type=service

When using multiple OIDC tenants, it’s your responsibility to configure tenant resolution appropriately. See the Quarkus OpenID Connect Multitenancy Guide.

Principal Mapping

While OIDC tenant resolution is entirely delegated to Quarkus, Polaris requires additional configuration to extract the Polaris principal and its roles from the credentials generated and validated by Quarkus. This part of the authentication process is configured with Polaris-specific properties that map JWT claims to Polaris principal fields:

polaris.oidc.principal-mapper.type=default
polaris.oidc.principal-mapper.id-claim-path=polaris/principal_id
polaris.oidc.principal-mapper.name-claim-path=polaris/principal_name

These properties are overridable per OIDC tenant:

polaris.oidc.oidc-tenant1.principal-mapper.id-claim-path=polaris/principal_id
polaris.oidc.oidc-tenant1.principal-mapper.name-claim-path=polaris/principal_name

❗Important

The default implementation of PrincipalMapper can only work with JWT tokens. If your IDP issues opaque tokens instead, you will need to provide a custom implementation.

Role Mapping

Similarly, Polaris requires additional configuration to map roles provided by Quarkus to roles defined in Polaris. The process happens in two phases: first, Quarkus maps the JWT claims to security roles, using the quarkus.oidc.roles.* properties; then, Polaris-specific properties are used to map the Quarkus-provided security roles to Polaris roles:

quarkus.oidc.roles.role-claim-path=polaris/roles
polaris.oidc.principal-roles-mapper.type=default
polaris.oidc.principal-roles-mapper.filter=^(?!profile$|email$).*
polaris.oidc.principal-roles-mapper.mappings[0].regex=^.*$
polaris.oidc.principal-roles-mapper.mappings[0].replacement=PRINCIPAL_ROLE:$0

These mappings can be overridden per OIDC tenant and used across different realms that rely on external identity providers. For example:

polaris.oidc.oidc-tenant1.principal-roles-mapper.type=custom
polaris.oidc.oidc-tenant1.principal-roles-mapper.filter=PRINCIPAL_ROLE:.*
polaris.oidc.oidc-tenant1.principal-roles-mapper.mappings[0].regex=PRINCIPAL_ROLE:(.*)
polaris.oidc.oidc-tenant1.principal-roles-mapper.mappings[0].replacement=PRINCIPAL_ROLE:$1

The default Authenticator expects the security identity to expose role names in the following format: PRINCIPAL_ROLE:<role name>. You can use the filter and mappings properties to adjust the role names as they appear in the JWT claims.

For example, assume that the security identity produced by Quarkus exposes the following roles: role_service_admin and role_catalog_admin. Polaris expects PRINCIPAL_ROLE:service_admin and PRINCIPAL_ROLE:catalog_admin respectively. The following configuration can be used to achieve the desired mapping:

# Exclude role names that don't start with "role_" 
polaris.oidc.principal-roles-mapper.filter=role_.*
# Extract the text after "role_" 
polaris.oidc.principal-roles-mapper.mappings[0].regex=role_(.*)
# Replace the extracted text with "PRINCIPAL_ROLE:" 
polaris.oidc.principal-roles-mapper.mappings[0].replacement=PRINCIPAL_ROLE:$1

See more examples below.

Example JWT Mappings

Example 1: Custom Claim Paths

  • JWT

    { 
  "polaris": 
  { 
    "roles": ["PRINCIPAL_ROLE:ALL"], 
    "principal_name": "root", 
    "principal_id": 1 
  } 
}

  • Configuration

    quarkus.oidc.roles.role-claim-path=polaris/roles 
polaris.oidc.principal-mapper.id-claim-path=polaris/principal_id 
polaris.oidc.principal-mapper.name-claim-path=polaris/principal_name

Example 2: Generic OIDC Claims

  • JWT

    { 
  "sub": "1", 
  "scope": "service_admin catalog_admin profile email", 
  "preferred_username": "root" 
}

  • Configuration

    quarkus.oidc.roles.role-claim-path=scope 
polaris.oidc.principal-mapper.id-claim-path=sub 
polaris.oidc.principal-mapper.name-claim-path=preferred_username 
polaris.oidc.principal-roles-mapper.filter=^(?!profile$|email$).* 
polaris.oidc.principal-roles-mapper.mappings[0].regex=^.*$ 
polaris.oidc.principal-roles-mapper.mappings[0].replacement=PRINCIPAL_ROLE:$0

  • Result

    Polaris roles: PRINCIPAL_ROLE:service_admin and PRINCIPAL_ROLE:catalog_admin