feat: implement decision-based routing with plugin architecture

Signed-off-by: bitliu <[email protected]>

Author: Xunzhuo

src/semantic-router/pkg/k8s/converter.go

@@ -17,6 +17,7 @@ limitations under the License.
 package k8s
 
 import (
+	"encoding/json"
 	"fmt"
 
 	"github.com/vllm-project/semantic-router/src/semantic-router/pkg/apis/vllm.ai/v1alpha1"
@@ -176,6 +177,10 @@ func (c *CRDConverter) convertDecision(decision v1alpha1.Decision) (config.Decis
 	for _, plugin := range decision.Plugins {
 		var pluginConfig interface{}
 		if plugin.Configuration != nil && plugin.Configuration.Raw != nil {
+			// Validate plugin configuration format
+			if err := validatePluginConfiguration(plugin.Type, plugin.Configuration.Raw); err != nil {
+				return config.Decision{}, fmt.Errorf("invalid configuration for plugin %s in decision %s: %w", plugin.Type, decision.Name, err)
+			}
 			// Store the raw bytes from RawExtension
 			// The Get*Config methods will unmarshal this to the appropriate type
 			pluginConfig = plugin.Configuration.Raw
@@ -188,3 +193,92 @@ func (c *CRDConverter) convertDecision(decision v1alpha1.Decision) (config.Decis
 
 	return configDecision, nil
 }
+
+// validatePluginConfiguration validates that plugin configuration matches the expected schema
+func validatePluginConfiguration(pluginType string, rawConfig []byte) error {
+	if len(rawConfig) == 0 {
+		return nil // Empty configuration is allowed
+	}
+
+	switch pluginType {
+	case "semantic-cache":
+		var cfg config.SemanticCachePluginConfig
+		if err := json.Unmarshal(rawConfig, &cfg); err != nil {
+			return fmt.Errorf("failed to unmarshal semantic-cache config: %w", err)
+		}
+		// Check for invalid fields
+		var rawMap map[string]interface{}
+		if err := json.Unmarshal(rawConfig, &rawMap); err == nil {
+			invalidFields := []string{}
+			for key := range rawMap {
+				if key != "enabled" && key != "similarity_threshold" {
+					invalidFields = append(invalidFields, key)
+				}
+			}
+			if len(invalidFields) > 0 {
+				return fmt.Errorf("semantic-cache plugin has invalid fields: %v. Valid fields are: enabled, similarity_threshold", invalidFields)
+			}
+		}
+
+	case "jailbreak":
+		var cfg config.JailbreakPluginConfig
+		if err := json.Unmarshal(rawConfig, &cfg); err != nil {
+			return fmt.Errorf("failed to unmarshal jailbreak config: %w", err)
+		}
+
+	case "pii":
+		var cfg config.PIIPluginConfig
+		if err := json.Unmarshal(rawConfig, &cfg); err != nil {
+			return fmt.Errorf("failed to unmarshal pii config: %w", err)
+		}
+		// Check for invalid fields that might be present
+		var rawMap map[string]interface{}
+		if err := json.Unmarshal(rawConfig, &rawMap); err == nil {
+			invalidFields := []string{}
+			for key := range rawMap {
+				if key != "enabled" && key != "threshold" {
+					invalidFields = append(invalidFields, key)
+				}
+			}
+			if len(invalidFields) > 0 {
+				return fmt.Errorf("pii plugin has invalid fields: %v. Valid fields are: enabled, threshold", invalidFields)
+			}
+		}
+
+	case "system_prompt":
+		var cfg config.SystemPromptPluginConfig
+		if err := json.Unmarshal(rawConfig, &cfg); err != nil {
+			return fmt.Errorf("failed to unmarshal system_prompt config: %w", err)
+		}
+		// Validate mode if present
+		if cfg.Mode != "" && cfg.Mode != "replace" && cfg.Mode != "insert" {
+			return fmt.Errorf("system_prompt mode must be 'replace' or 'insert', got: %s", cfg.Mode)
+		}
+
+	case "header_mutation":
+		var cfg config.HeaderMutationPluginConfig
+		if err := json.Unmarshal(rawConfig, &cfg); err != nil {
+			return fmt.Errorf("failed to unmarshal header_mutation config: %w", err)
+		}
+		// Validate that at least one operation is specified
+		if len(cfg.Add) == 0 && len(cfg.Update) == 0 && len(cfg.Delete) == 0 {
+			return fmt.Errorf("header_mutation plugin must specify at least one of: add, update, delete")
+		}
+		// Validate header pairs
+		for _, h := range cfg.Add {
+			if h.Name == "" {
+				return fmt.Errorf("header_mutation add: header name cannot be empty")
+			}
+		}
+		for _, h := range cfg.Update {
+			if h.Name == "" {
+				return fmt.Errorf("header_mutation update: header name cannot be empty")
+			}
+		}
+
+	default:
+		return fmt.Errorf("unknown plugin type: %s", pluginType)
+	}
+
+	return nil
+}

src/semantic-router/pkg/k8s/testdata/input/01-basic.yaml

@@ -69,7 +69,7 @@ spec:
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.9
+            similarity_threshold: 0.9
 
     - name: "general_tech"
       priority: 50

src/semantic-router/pkg/k8s/testdata/input/09-keyword-plugin.yaml

@@ -53,7 +53,7 @@ spec:
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.95
+            similarity_threshold: 0.95
         - type: "header_mutation"
           configuration:
             add:

src/semantic-router/pkg/k8s/testdata/input/10-embedding-plugin.yaml

@@ -59,8 +59,7 @@ spec:
         - type: "pii"
           configuration:
             enabled: true
-            redact_mode: "mask"
-            entities: ["CREDIT_CARD", "SSN", "EMAIL"]
+            threshold: 0.8
         - type: "jailbreak"
           configuration:
             enabled: true

src/semantic-router/pkg/k8s/testdata/input/11-domain-plugin.yaml

@@ -55,5 +55,5 @@ spec:
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.90
+            similarity_threshold: 0.90
 

src/semantic-router/pkg/k8s/testdata/input/12-keyword-embedding-plugin.yaml

@@ -67,7 +67,7 @@ spec:
         - type: "jailbreak"
           configuration:
             enabled: true
-            threshold: 0.90
+            similarity_threshold: 0.90
         - type: "system_prompt"
           configuration:
             prompt: "You are a security expert. Provide helpful security guidance while being cautious about potential misuse."

src/semantic-router/pkg/k8s/testdata/input/13-keyword-domain-plugin.yaml

@@ -62,13 +62,12 @@ spec:
         - type: "pii"
           configuration:
             enabled: true
-            redact_mode: "hash"
-            entities: ["PERSON", "DATE_OF_BIRTH", "MEDICAL_RECORD"]
+            threshold: 0.9
         - type: "system_prompt"
           configuration:
             prompt: "You are a medical information assistant. Provide general health information but always advise users to consult healthcare professionals."
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.88
+            similarity_threshold: 0.88
 

src/semantic-router/pkg/k8s/testdata/input/14-domain-embedding-plugin.yaml

@@ -63,8 +63,7 @@ spec:
         - type: "pii"
           configuration:
             enabled: true
-            redact_mode: "mask"
-            entities: ["CREDIT_CARD", "BANK_ACCOUNT", "SSN"]
+            threshold: 0.85
         - type: "system_prompt"
           configuration:
             prompt: "You are a financial information assistant. Provide general financial education but remind users this is not professional financial advice."
@@ -75,5 +74,5 @@ spec:
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.92
+            similarity_threshold: 0.92
 

src/semantic-router/pkg/k8s/testdata/input/15-keyword-embedding-domain-plugin.yaml

@@ -87,19 +87,18 @@ spec:
         - type: "pii"
           configuration:
             enabled: true
-            redact_mode: "hash"
-            entities: ["PERSON", "ORGANIZATION", "EMAIL", "PHONE_NUMBER"]
+            threshold: 0.9
         - type: "jailbreak"
           configuration:
             enabled: true
-            threshold: 0.88
+            similarity_threshold: 0.88
         - type: "system_prompt"
           configuration:
             prompt: "You are a legal compliance assistant. Provide accurate information about regulations and compliance requirements. Always remind users to consult legal professionals for specific advice."
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.93
+            similarity_threshold: 0.93
         - type: "header_mutation"
           configuration:
             add:
@@ -128,12 +127,11 @@ spec:
         - type: "pii"
           configuration:
             enabled: true
-            redact_mode: "mask"
-            entities: ["PERSON", "ORGANIZATION", "FINANCIAL_DATA"]
+            threshold: 0.85
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.90
+            similarity_threshold: 0.90
         - type: "header_mutation"
           configuration:
             add:
@@ -157,5 +155,5 @@ spec:
         - type: "semantic-cache"
           configuration:
             enabled: true
-            threshold: 0.85
+            similarity_threshold: 0.85
 

src/semantic-router/pkg/k8s/testdata/output/01-basic.yaml

@@ -122,7 +122,7 @@ decisions:
         - type: semantic-cache
           configuration:
             enabled: true
-            threshold: 0.9
+            similarity_threshold: 0.9
     - name: general_tech
       description: General technical queries - use small model for efficiency
       priority: 50