add examples for Prometheus auth

content/docs/2.6/scalers/predictkube.md

@@ -42,6 +42,7 @@ triggers:
 ### Authentication Parameters
 
 Predictkube Scaler supports one type of authentication - authentication by API key.
+Prometheus supports all authentication methods that are available in Prometheus Scaler.
 
 **Auth gateway based authentication:**
 
@@ -59,6 +60,8 @@ metadata:
 type: Opaque
 data:
   apiKey: # Required: base64 encoded value of PredictKube apiKey
+  bearerToken: "BEARER_TOKEN" # Optional: bearer authentication for Prometheus
+  ca: "CUSTOM_CA_CERT" # Optional: certificate authority file for TLS client authentication for Prometheus
 ---
 apiVersion: keda.sh/v1alpha1
 kind: TriggerAuthentication
@@ -71,6 +74,14 @@ spec:
   - parameter: apiKey
     name: predictkube-secrets
     key: apiKey
+    # Optional: might be required if you're using bearer auth for Promethrus
+  - parameter: bearerToken
+    name: keda-prom-secret
+    key: bearerToken
+    # Optional: might be required if you're using a custom CA for Promethrus
+  - parameter: ca
+    name: keda-prom-secret
+    key: ca
 ---
 apiVersion: keda.sh/v1alpha1
 kind: ScaledObject
@@ -93,7 +104,8 @@ spec:
       prometheusAddress: http://<prometheus-host>:9090
       query: sum(rate(http_requests_total{deployment="my-deployment"}[2m])) # Note: query must return a vector/scalar single element response
       queryStep: "2m" # Note: query step duration for range prometheus queries
-      threshold: '100'
+      threshold: "100"
+      authModes: "bearer" # might be required if you're using bearer auth for Promethrus
     authenticationRef:
       name: keda-trigger-auth-predictkube-secret
 ```