adding rate limit yamls

devops/azure/chart/helm-config.yaml

@@ -12,3 +12,13 @@ image:
   repository: #{container-registry}#.azurecr.io
   branch: #{ENVIRONMENT_NAME}#
   tag: #{Build.SourceVersion}#
+
+################################################################################
+# Specify the Rate limit Settings
+#
+envoyFilter:
+  enabled: false
+  rateLimit:
+    max_tokens: 100
+    tokens_per_fill: 100
+    fill_interval: 60
\ No newline at end of file

devops/azure/chart/templates/ratelimit.yaml

+#  Copyright © Microsoft Corporation
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+
+{{ if .Values.envoyFilter.enabled }}
+apiVersion: networking.istio.io/v1alpha3
+kind: EnvoyFilter
+metadata:
+  name: {{ .Release.Name }}-ratelimit
+  namespace: osdu
+spec:
+  workloadSelector:
+    labels:
+      app: {{ .Release.Name }}
+  configPatches:
+    - applyTo: HTTP_FILTER
+      match:
+        context: SIDECAR_INBOUND   # will match outbound listeners in all sidecars
+      listener:
+        filterChain:
+          filter:
+            name: envoy.http_connection_manager
+      patch:
+        operation: INSERT_BEFORE
+        value:
+          name: envoy.filters.http.local_ratelimit
+          typed_config:
+            "@type": type.googleapis.com/udpa.type.v1.TypedStruct
+            type_url: type.googleapis.com/envoy.extensions.filters.http.local_ratelimit.v3.LocalRateLimit
+            value:
+              stat_prefix: http_local_rate_limiter
+              token_bucket:
+                max_tokens: {{ .Values.envoyFilter.rateLimit.max_tokens }}    #The maximum tokens that the bucket can hold. 
+                tokens_per_fill: {{ .Values.envoyFilter.rateLimit.tokens_per_fill }}  #The number of tokens added to the bucket during each fill interval.    
+                fill_interval: {{ .Values.envoyFilter.rateLimit.fill_interval }}   #The fill interval that tokens are added to the bucket in seconds.
+              filter_enabled:
+                runtime_key: local_rate_limit_enabled
+                default_value:
+                  numerator: 100
+                  denominator: HUNDRED
+              filter_enforced:
+                runtime_key: local_rate_limit_enforced
+                default_value:
+                  numerator: 100
+                  denominator: HUNDRED
+              response_headers_to_add:
+                - append: true
+                  header:
+                    key: x-local-rate-limit
+                    value: 'true'
+{{ end }}
\ No newline at end of file

devops/azure/chart/values.yaml

@@ -19,3 +19,13 @@ image:
   repository: community.opengroup.org:5555/osdu/platform/system/dataset
   branch: master
   tag: latest
+
+################################################################################
+# Specify the Rate limit Settings
+#
+envoyFilter:
+  enabled: false
+  rateLimit:
+    max_tokens: 100
+    tokens_per_fill: 100
+    fill_interval: 60