NPA-4284: Add mirror request headers in response script

Author: ellie-bound1-NHSD

proxies/live/apiproxy/policies/MirrorRequestHeaders.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<Script async="false" continueOnError="true" enabled="true" name="MirrorRequestHeaders">
+    <DisplayName>MirrorRequestHeaders</DisplayName>
+    <Properties/>
+    <ResourceURL>py://mirror-request-headers.py</ResourceURL>
+</Script>

proxies/live/apiproxy/policies/TranslateRequestHeaders.xml

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="UTF-8" standalone="yes"?>
-<Script async="false" continueOnError="false" enabled="true" name="TranslateRequestHeaders">
+<Script async="false" continueOnError="true" enabled="true" name="TranslateRequestHeaders">
     <DisplayName>TranslateRequestHeaders</DisplayName>
     <Properties/>
     <ResourceURL>py://translate-request-headers.py</ResourceURL>

proxies/live/apiproxy/resources/py/mirror-request-headers.py

@@ -0,0 +1,6 @@
+# Access original request headers dictionary
+request_headers = JSON.parse(flow.getVariable("original.headers"))
+
+# Loop through request headers and set them as response headers
+for key, value in request_headers.items():
+    flow.setVariable("response.header.{0}".format(key), value)

proxies/live/apiproxy/resources/py/translate-request-headers.py

@@ -1,12 +1,26 @@
+def get_request_headers():
+    request_header_names = flow.getVariable("request.headers.names")
+    request_headers = {}
+    for name in request_header_names:
+        request_headers[name] = flow.getVariable("request.header." + name)
+
+    return request_headers
+
+
 # Access request headers dictionary
-request_headers = request.headers
+request_headers = get_request_headers()
+
+# Store copy of original request headers
+flow.setVariable("original.headers", str(request_headers))
 
 # Map of lowercase header name to desired parcel case header name
 request_header_translation = {"x-request-id": "X-Request-ID", "x-correlation-id": "X-Correlation-ID"}
 
 # Loop through request headers
 for key, value in request_headers.items():
-    key = key.lower()
-    desired_name = request_header_translation.get(key)
+    desired_name = request_header_translation.get(key.lower())
     if desired_name:
-        flow.setVariable(f"request.header.{desired_name}", value)
+        # Remove original header
+        flow.removeVariable("request.header." + key)
+        # Set header with correct casing
+        flow.setVariable("request.header." + desired_name, value)

proxies/live/apiproxy/targets/target.xml

@@ -67,15 +67,22 @@
             </Request>
         </Flow>
     </Flows>
-
     <PostFlow>
         <Response>
             <Step>
                 <Name>SetMimeType</Name>
             </Step>
+            <Step>
+                <Name>MirrorRequestHeaders</Name>
+            </Step>
         </Response>
     </PostFlow>
     <FaultRules>
+        <FaultRule name="default">
+            <Step>
+                <Name>MirrorRequestHeaders</Name>
+            </Step>
+        </FaultRule>
         <FaultRule name="401_Unauthorized">
             <Step>
                 <Name>RaiseFault.401Unauthorized</Name>