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

Prerequisites

  • Kubernetes cluster running Kubernetes v1.19.0 or greater.
  • Have OSM installed.
  • Have kubectl available to interact with the API server.
  • Have osm CLI available for managing the service mesh.

HTTP(S) mesh-wide Egress passthrough demo

  1. Enable global egress passthrough if not enabled:

    export osm_namespace=<osm-namespace> # Replace <osm-namespace> with the namespace where OSM is installed
kubectl patch meshconfig osm-mesh-config -n "$osm_namespace" -p '{"spec":{"traffic":{"enableEgress":true}}}'  --type=merge

  2. 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
osm namespace add curl

# Deploy curl client in the curl namespace
kubectl apply -f https://raw.githubusercontent.com/openservicemesh/osm/main/docs/example/manifests/samples/curl/curl.yaml -n curl

    Confirm the curl client pod is up and running.

    $ kubectl get pods -n curl
NAME                    READY   STATUS    RESTARTS   AGE
curl-54ccc6954c-9rlvp   2/2     Running   0          20s

  3. Confirm the curl client is able to make successful HTTPS requests to the httpbin.org website on port 443.

    $ kubectl exec -n curl -ti "$(kubectl get pod -n curl -l app=curl -o jsonpath='{.items[0].metadata.name}')" -c curl -- curl -I https://httpbin.org:443
HTTP/2 200
date: Tue, 16 Mar 2021 22:19:00 GMT
content-type: text/html; charset=utf-8
content-length: 9593
server: gunicorn/19.9.0
access-control-allow-origin: *
access-control-allow-credentials: true

    A 200 OK response indicates the HTTPS request from the curl client to the httpbin.org website was successful.

  4. Confirm the HTTPS requests fail when mesh-wide egress is disabled.

    kubectl patch meshconfig osm-mesh-config -n "$osm_namespace" -p '{"spec":{"traffic":{"enableEgress":false}}}'  --type=merge

    $ kubectl exec -n curl -ti "$(kubectl get pod -n curl -l app=curl -o jsonpath='{.items[0].metadata.name}')" -c curl -- curl -I https://httpbin.org:443
  curl: (35) OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to httpbin.org:443
  command terminated with exit code 35