Remove double slashes from requests

Problem: double slashes in a request can cause the request not to resolve

Any request that contains a two (or more) consecutive slashes can result in a 404 error. For example /hello//world/. The problem in this example is the "//" between hello and world.

Solution: filter for double slashes

Apply a configuration to your Istio ingress to filter for double slashes in requests and replace them.

1. Create a new configuration file named apigee-merge-slash-filter.yaml.
2. Paste the following content into the file:

   apiVersion: networking.istio.io/v1alpha3
   kind: EnvoyFilter
   metadata:
     name: apigee-merge-slashes
     namespace: istio-system
   spec:
     workloadSelector:
       labels:
         app: istio-ingressgateway
     configPatches:
     - applyTo: NETWORK_FILTER # http connection manager is a filter in Envoy
       match:
         context: GATEWAY
         listener:
           filterChain:
             filter:
               name: "envoy.http_connection_manager"
       patch:
         operation: MERGE
         value:
           typed_config:
             "@type": "type.googleapis.com/envoy.config.filter.network.http_connection_manager.v2.HttpConnectionManager"
             merge_slashes: true

3. Apply the configuration with the following command:

   kubectl apply -f apigee-merge-slash-filter.yaml