api: add GCP OIDC auth support in BackendSecurityPolicies

api/v1alpha1/api.go

@@ -414,7 +414,7 @@ type AIServiceBackendSpec struct {
 type VersionedAPISchema struct {
 	// Name is the name of the API schema of the AIGatewayRoute or AIServiceBackend.
 	//
-	// +kubebuilder:validation:Enum=OpenAI;AWSBedrock;AzureOpenAI
+	// +kubebuilder:validation:Enum=OpenAI;AWSBedrock;AzureOpenAI;GCPVertexAI;GCPAnthropic
 	Name APISchema `json:"name"`
 
 	// Version is the version of the API schema.
@@ -450,6 +450,17 @@ const (
 	//
 	// https://learn.microsoft.com/en-us/azure/ai-services/openai/reference#api-specs
 	APISchemaAzureOpenAI APISchema = "AzureOpenAI"
+	// APISchemaGCPVertexAI is the schema followed by Gemini models hosted on GCP's Vertex AI platform.
+	// Note: Using this schema requires a BackendSecurityPolicy to be configured and attached,
+	// as the transformation will use the gcp-region and project-name from the BackendSecurityPolicy.
+	//
+	// https://cloud.google.com/vertex-ai/docs/reference/rest/v1/projects.locations.endpoints/generateContent?hl=en
+	APISchemaGCPVertexAI APISchema = "GCPVertexAI"
+	// APISchemaGCPAnthropic is the schema followed by Anthropic models hosted on GCP's Vertex AI platform.
+	// This is majorly the Anthropic API with some GCP specific parameters as described in below URL.
+	//
+	// https://docs.anthropic.com/en/api/claude-on-vertex-ai
+	APISchemaGCPAnthropic APISchema = "GCPAnthropic"
 )
 
 const (
@@ -465,6 +476,7 @@ const (
 	BackendSecurityPolicyTypeAPIKey           BackendSecurityPolicyType = "APIKey"
 	BackendSecurityPolicyTypeAWSCredentials   BackendSecurityPolicyType = "AWSCredentials"
 	BackendSecurityPolicyTypeAzureCredentials BackendSecurityPolicyType = "AzureCredentials"
+	BackendSecurityPolicyTypeGCPCredentials   BackendSecurityPolicyType = "GCPCredentials"
 )
 
 // BackendSecurityPolicy specifies configuration for authentication and authorization rules on the traffic
@@ -487,9 +499,9 @@ type BackendSecurityPolicy struct {
 // Only one type of BackendSecurityPolicy can be defined.
 // +kubebuilder:validation:MaxProperties=2
 type BackendSecurityPolicySpec struct {
-	// Type specifies the auth mechanism used to access the provider. Currently, only "APIKey", "AWSCredentials", and "AzureCredentials" are supported.
+	// Type specifies the type of the backend security policy.
 	//
-	// +kubebuilder:validation:Enum=APIKey;AWSCredentials;AzureCredentials
+	// +kubebuilder:validation:Enum=APIKey;AWSCredentials;AzureCredentials;GCPCredentials
 	Type BackendSecurityPolicyType `json:"type"`
 
 	// APIKey is a mechanism to access a backend(s). The API key will be injected into the Authorization header.
@@ -506,6 +518,10 @@ type BackendSecurityPolicySpec struct {
 	//
 	// +optional
 	AzureCredentials *BackendSecurityPolicyAzureCredentials `json:"azureCredentials,omitempty"`
+	// GCPCredentials is a mechanism to access a backend(s). GCP specific logic will be applied.
+	//
+	// +optional
+	GCPCredentials *BackendSecurityPolicyGCPCredentials `json:"gcpCredentials,omitempty"`
 }
 
 // BackendSecurityPolicyList contains a list of BackendSecurityPolicy
@@ -543,6 +559,72 @@ type BackendSecurityPolicyOIDC struct {
 	Aud string `json:"aud,omitempty"`
 }
 
+type GCPWorkLoadIdentityFederationConfig struct {
+	// ProjectID is the GCP project ID.
+	//
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	ProjectID string `json:"projectID"`
+
+	// WorkloadIdentityProvider is the external auth provider to be used to authenticate against GCP.
+	// https://cloud.google.com/iam/docs/workload-identity-federation?hl=en
+	// Currently only OIDC is supported.
+	//
+	// +kubebuilder:validation:Required
+	WorkloadIdentityProvider GCPWorkloadIdentityProvider `json:"workloadIdentityProvider"`
+
+	// WorkloadIdentityPoolName is the name of the workload identity pool defined in GCP.
+	// https://cloud.google.com/iam/docs/workload-identity-federation?hl=en
+	//
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	WorkloadIdentityPoolName string `json:"workloadIdentityPoolName"`
+
+	// ServiceAccountImpersonation is the service account impersonation configuration.
+	// This is used to impersonate a service account when getting access token.
+	//
+	// +optional
+	ServiceAccountImpersonation *GCPServiceAccountImpersonationConfig `json:"serviceAccountImpersonation,omitempty"`
+}
+
+// GCPWorkloadIdentityProvider specifies the external identity provider to be used to authenticate against GCP.
+// The external identity provider can be AWS, Microsoft, etc but must be pre-registered in the GCP project
+//
+// https://cloud.google.com/iam/docs/workload-identity-federation
+type GCPWorkloadIdentityProvider struct {
+	// Name of the external identity provider as registered on Google Cloud Platform.
+	//
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	Name string `json:"name"`
+
+	// OIDCProvider is the generic OIDCProvider fields.
+	//
+	// +kubebuilder:validation:Required
+	OIDCProvider BackendSecurityPolicyOIDC `json:"OIDCProvider"`
+}
+
+type GCPServiceAccountImpersonationConfig struct {
+	// ServiceAccountName is the name of the service account to impersonate.
+	//
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	ServiceAccountName string `json:"serviceAccountName"`
+	// ServiceAccountProjectName is the project name in which the service account is registered.
+	//
+	// +kubebuilder:validation:Required
+	// +kubebuilder:validation:MinLength=1
+	ServiceAccountProjectName string `json:"serviceAccountProjectName"`
+}
+
+// BackendSecurityPolicyGCPCredentials contains the supported authentication mechanisms to access GCP.
+type BackendSecurityPolicyGCPCredentials struct {
+	// WorkLoadIdentityFederationConfig is the configuration for the GCP Workload Identity Federation.
+	//
+	// +kubebuilder:validation:Required
+	WorkLoadIdentityFederationConfig GCPWorkLoadIdentityFederationConfig `json:"workLoadIdentityFederationConfig"`
+}
+
 // BackendSecurityPolicyAzureCredentials contains the supported authentication mechanisms to access Azure.
 // Only one of ClientSecretRef or OIDCExchangeToken must be specified. Credentials will not be generated if
 // neither are set.

examples/basic/basic.yaml

@@ -91,6 +91,24 @@ spec:
     kind: BackendSecurityPolicy
     group: aigateway.envoyproxy.io
 ---
+# GCP Example
+apiVersion: aigateway.envoyproxy.io/v1alpha1
+kind: AIServiceBackend
+metadata:
+  name: envoy-ai-gateway-basic-gcp
+  namespace: default
+spec:
+  schema:
+    name: GCPVertexAI
+  backendRef:
+    name: envoy-ai-gateway-basic-gcp
+    kind: Backend
+    group: gateway.envoyproxy.io
+  backendSecurityPolicyRef:
+    name: envoy-ai-gateway-basic-gcp-credentials
+    kind: BackendSecurityPolicy
+    group: aigateway.envoyproxy.io
+---
 apiVersion: aigateway.envoyproxy.io/v1alpha1
 kind: AIServiceBackend
 metadata:
@@ -148,6 +166,28 @@ spec:
       secretRef:
         name: envoy-ai-gateway-basic-aws-credentials
 ---
+apiVersion: aigateway.envoyproxy.io/v1alpha1
+kind: BackendSecurityPolicy
+metadata:
+  name: envoy-ai-gateway-basic-gcp-credentials
+  namespace: default
+spec:
+  type: GCPCredentials
+  gcpCredentials:
+    workLoadIdentityFederationConfig:
+      projectID: GCP_PROJECT_ID  # Replace with your GCP project ID
+      workloadIdentityPoolName: GCP_WORKLOAD_IDENTITY_POOL  # Replace with your workload identity pool name
+      workloadIdentityProvider:
+        name: GCP_IDENTITY_PROVIDER_NAME  # Replace with the identity provider configured with GCP
+        OIDCProvider:
+          oidc:
+            provider:
+              issuer: GCP_OIDC_PROVIDER_ISSUER  # Replace with your OIDC provider issuer
+            clientID: GCP_OIDC_CLIENT_ID  # Replace with your OIDC client ID
+            clientSecret:
+              name: envoy-ai-gateway-basic-gcp-client-secret
+              namespace: default
+---
 apiVersion: gateway.envoyproxy.io/v1alpha1
 kind: Backend
 metadata:
@@ -172,6 +212,17 @@ spec:
 ---
 apiVersion: gateway.envoyproxy.io/v1alpha1
 kind: Backend
+metadata:
+  name: envoy-ai-gateway-basic-gcp
+  namespace: default
+spec:
+  endpoints:
+    - fqdn:
+        hostname: us-central1-aiplatform.googleapis.com
+        port: 443
+---
+apiVersion: gateway.envoyproxy.io/v1alpha1
+kind: Backend
 metadata:
   name: envoy-ai-gateway-basic-azure
   namespace: default
@@ -211,6 +262,20 @@ spec:
 ---
 apiVersion: gateway.networking.k8s.io/v1alpha3
 kind: BackendTLSPolicy
+metadata:
+  name: envoy-ai-gateway-basic-gcp-tls
+  namespace: default
+spec:
+  targetRefs:
+    - group: 'gateway.envoyproxy.io'
+      kind: Backend
+      name: envoy-ai-gateway-basic-gcp
+  validation:
+    wellKnownCACertificates: "System"
+    hostname: us-central1-aiplatform.googleapis.com
+---
+apiVersion: gateway.networking.k8s.io/v1alpha3
+kind: BackendTLSPolicy
 metadata:
   name: envoy-ai-gateway-basic-azure-tls
   namespace: default
@@ -254,6 +319,14 @@ stringData:
     aws_access_key_id = AWS_ACCESS_KEY_ID
     aws_secret_access_key = AWS_SECRET_ACCESS_KEY
 ---
+apiVersion: v1
+kind: Secret
+metadata:
+  name: envoy-ai-gateway-basic-gcp-client-secret
+  namespace: default
+stringData:
+  client-secret: "GCP_OIDC_CLIENT_SECRET"  # Replace with your OIDC client secret
+---
 apiVersion: aigateway.envoyproxy.io/v1alpha1
 kind: AIServiceBackend
 metadata:

filterapi/filterconfig.go

@@ -202,6 +202,8 @@ type BackendAuth struct {
 	AWSAuth *AWSAuth `json:"aws,omitempty"`
 	// AzureAuth specifies the location of Azure access token file.
 	AzureAuth *AzureAuth `json:"azure,omitempty"`
+	// GCPAuth specifies the location of GCP credential file.
+	GCPAuth *GCPAuth `json:"gcp,omitempty"`
 }
 
 // AWSAuth defines the credentials needed to access AWS.
@@ -224,6 +226,16 @@ type AzureAuth struct {
 	AccessToken string `json:"accessToken"`
 }
 
+// GCPAuth defines the file containing GCP credential that will be mounted to the external proc.
+type GCPAuth struct {
+	// AccessToken is the access token as a literal string.
+	AccessToken string `json:"accessToken"`
+	// Region is the GCP region to use for the request.
+	Region string `json:"region"`
+	// ProjectName is the GCP project name to use for the request.
+	ProjectName string `json:"projectName"`
+}
+
 // UnmarshalConfigYaml reads the file at the given path and unmarshals it into a Config struct.
 func UnmarshalConfigYaml(path string) (*Config, error) {
 	raw, err := os.ReadFile(path)

manifests/charts/ai-gateway-crds-helm/templates/aigateway.envoyproxy.io_aigatewayroutes.yaml

@@ -505,6 +505,8 @@ spec:
                     - OpenAI
                     - AWSBedrock
                     - AzureOpenAI
+                    - GCPVertexAI
+                    - GCPAnthropic
                     type: string
                   version:
                     description: |-

manifests/charts/ai-gateway-crds-helm/templates/aigateway.envoyproxy.io_aiservicebackends.yaml

@@ -177,6 +177,8 @@ spec:
                     - OpenAI
                     - AWSBedrock
                     - AzureOpenAI
+                    - GCPVertexAI
+                    - GCPAnthropic
                     type: string
                   version:
                     description: |-