Egress Gateway Passthrough to Unknown Destinations

Accessing external services via Egress Gateway without Egress policies

This guide demonstrates a client within the service mesh accessing destinations external to the mesh via egress gateway using FSM’s Egress capability to passthrough traffic to unknown destinations without an Egress policy.


  • Kubernetes cluster version v1.19.0 or higher.
  • Interact with the API server using kubectl.
  • FSM CLI installed.
  • FSM Ingress Controller installed followed by installation document

Egress Gateway passthrough demo

  1. Deploy egress gateway via fsm.

    fsm install --set=fsm.egressGateway.enabled=true

    Or, enable egress gateway with FSM CLI.

    fsm egressgateway enable

    There are more options supported by fsm egressgateway enable.

  2. Enable global egress passthrough if not enabled:

    export FSM_NAMESPACE=fsm-system # Replace fsm-system with the namespace where FSM is installed
    kubectl patch meshconfig fsm-mesh-config -n "$FSM_NAMESPACE" -p '{"spec":{"traffic":{"enableEgress":true}}}' --type=merge
  3. Deploy the curl client into the curl namespace after enrolling its namespace to the mesh.

    # Create the curl namespace
    kubectl create namespace curl
    # Add the namespace to the mesh
    fsm namespace add curl
    # Deploy curl client in the curl namespace
    kubectl apply -n curl -f

    Confirm the curl client pod is up and running.

    kubectl get pods -n curl 
    NAME                    READY   STATUS    RESTARTS   AGE
    curl-7bb5845476-8s9kv   2/2     Running   0          29s
  4. Confirm the curl client is able to make successful HTTP requests to the website on port 80.

    kubectl exec "$(kubectl get pod -n curl -l app=curl -o jsonpath='{}')" -n curl -c curl -- curl -sI
    HTTP/1.1 200 OK
    Date: Fri, 27 Jan 2023 22:27:53 GMT
    Content-Type: application/json
    Content-Length: 258
    Connection: keep-alive
    Server: gunicorn/19.9.0
    Access-Control-Allow-Origin: *
    Access-Control-Allow-Credentials: true

    A 200 OK response indicates the HTTP request from the curl client to the website was successful.

  5. Confirm the HTTP requests fail when mesh-wide egress is disabled.

    kubectl patch meshconfig fsm-mesh-config -n "$FSM_NAMESPACE" -p '{"spec":{"traffic":{"enableEgress":false}}}'  --type=merge
    kubectl exec "$(kubectl get pod -n curl -l app=curl -o jsonpath='{}')" -n curl -c curl -- curl -sI
    command terminated with exit code 7


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