istio
/
istio.io
mirror of https://github.com/istio/istio.io.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity
istio.io/content/en/docs/tasks/traffic-management/egress/http-proxy/index.md

8.3 KiB
Raw Permalink Blame History

title description weight keywords aliases owner test
Using an External HTTPS Proxy Describes how to configure Istio to let applications use an external HTTPS proxy. 60
traffic-management
egress
/docs/examples/advanced-gateways/http-proxy/
istio/wg-networking-maintainers yes

The Configure an Egress Gateway example shows how to direct traffic to external services from your mesh via an Istio edge component called Egress Gateway. However, some cases require an external, legacy (non-Istio) HTTPS proxy to access external services. For example, your company may already have such a proxy in place and all the applications within the organization may be required to direct their traffic through it.

This example shows how to enable access to an external HTTPS proxy. Since applications use the HTTP CONNECT method to establish connections with HTTPS proxies, configuring traffic to an external HTTPS proxy is different from configuring traffic to external HTTP and HTTPS services.

{{< boilerplate before-you-begin-egress >}}

Deploy an HTTPS proxy

To simulate a legacy proxy and only for this example, you deploy an HTTPS proxy inside your cluster. Also, to simulate a more realistic proxy that is running outside of your cluster, you will address the proxy's pod by its IP address and not by the domain name of a Kubernetes service. This example uses Squid but you can use any HTTPS proxy that supports HTTP CONNECT.

  1. Create a namespace for the HTTPS proxy, without labeling it for sidecar injection. Without the label, sidecar injection is disabled in the new namespace so Istio will not control the traffic there. You need this behavior to simulate the proxy being outside of the cluster.

    {{< text bash >}} $ kubectl create namespace external {{< /text >}}

  2. Create a configuration file for the Squid proxy.

    {{< text bash >}} $ cat < ./proxy.conf http_port 3128

    acl SSL_ports port 443 acl CONNECT method CONNECT

    http_access deny CONNECT !SSL_ports http_access allow localhost manager http_access deny manager http_access allow all

    coredump_dir /var/spool/squid EOF {{< /text >}}

  3. Create a Kubernetes ConfigMap to hold the configuration of the proxy:

    {{< text bash >}} $ kubectl create configmap proxy-configmap -n external --from-file=squid.conf=./proxy.conf {{< /text >}}

  4. Deploy a container with Squid:

    {{< text bash >}} $ kubectl apply -f - <<EOF apiVersion: apps/v1 kind: Deployment metadata: name: squid namespace: external spec: replicas: 1 selector: matchLabels: app: squid template: metadata: labels: app: squid spec: volumes: - name: proxy-config configMap: name: proxy-configmap containers: - name: squid image: sameersbn/squid:3.5.27 imagePullPolicy: IfNotPresent volumeMounts: - name: proxy-config mountPath: /etc/squid readOnly: true EOF {{< /text >}}

  5. Deploy the [sleep]({{< github_tree >}}/samples/sleep) sample in the external namespace to test traffic to the proxy without Istio traffic control.

    {{< text bash >}} $ kubectl apply -n external -f @samples/sleep/sleep.yaml@ {{< /text >}}

  6. Obtain the IP address of the proxy pod and define the PROXY_IP environment variable to store it:

    {{< text bash >}} export PROXY_IP="(kubectl get pod -n external -l app=squid -o jsonpath={.items..podIP})" {{< /text >}}

  7. Define the PROXY_PORT environment variable to store the port of your proxy. In this case, Squid uses port 3128.

    {{< text bash >}} $ export PROXY_PORT=3128 {{< /text >}}

  8. Send a request from the sleep pod in the external namespace to an external service via the proxy:

    {{< text bash >}} kubectl exec "(kubectl get pod -n external -l app=sleep -o jsonpath={.items..metadata.name})" -n external -- sh -c "HTTPS_PROXY=$PROXY_IP:$PROXY_PORT curl https://en.wikipedia.org/wiki/Main_Page" | grep -o ""

    {{< /text >}}

  9. Check the access log of the proxy for your request:

    {{< text bash >}} kubectl exec "(kubectl get pod -n external -l app=squid -o jsonpath={.items..metadata.name})" -n external -- tail /var/log/squid/access.log 1544160065.248 228 172.30.109.89 TCP_TUNNEL/200 87633 CONNECT en.wikipedia.org:443 - HIER_DIRECT/91.198.174.192 - {{< /text >}}

So far, you completed the following tasks without Istio:

  • You deployed the HTTPS proxy.
  • You used curl to access the wikipedia.org external service through the proxy.

Next, you must configure the traffic from the Istio-enabled pods to use the HTTPS proxy.

Configure traffic to external HTTPS proxy

  1. Define a TCP (not HTTP!) Service Entry for the HTTPS proxy. Although applications use the HTTP CONNECT method to establish connections with HTTPS proxies, you must configure the proxy for TCP traffic, instead of HTTP. Once the connection is established, the proxy simply acts as a TCP tunnel.

    {{< text bash >}} $ kubectl apply -f - <<EOF apiVersion: networking.istio.io/v1 kind: ServiceEntry metadata: name: proxy spec: hosts:

    • my-company-proxy.com # ignored addresses:
    • $PROXY_IP/32 ports:
    • number: $PROXY_PORT name: tcp protocol: TCP location: MESH_EXTERNAL EOF {{< /text >}}

  2. Send a request from the sleep pod in the default namespace. Because the sleep pod has a sidecar, Istio controls its traffic.

    {{< text bash >}} $ kubectl exec "$SOURCE_POD" -c sleep -- sh -c "HTTPS_PROXY=$PROXY_IP:$PROXY_PORT curl https://en.wikipedia.org/wiki/Main_Page" | grep -o ""

    {{< /text >}}

  3. Check the Istio sidecar proxy's logs for your request:

    {{< text bash >}} $ kubectl logs "$SOURCE_POD" -c istio-proxy [2018-12-07T10:38:02.841Z] "- - -" 0 - 702 87599 92 - "-" "-" "-" "-" "172.30.109.95:3128" outbound|3128||my-company-proxy.com 172.30.230.52:44478 172.30.109.95:3128 172.30.230.52:44476 - {{< /text >}}

  4. Check the access log of the proxy for your request:

    {{< text bash >}} kubectl exec "(kubectl get pod -n external -l app=squid -o jsonpath={.items..metadata.name})" -n external -- tail /var/log/squid/access.log 1544160065.248 228 172.30.109.89 TCP_TUNNEL/200 87633 CONNECT en.wikipedia.org:443 - HIER_DIRECT/91.198.174.192 - {{< /text >}}

Understanding what happened

In this example, you took the following steps:

  1. Deployed an HTTPS proxy to simulate an external proxy.
  2. Created a TCP service entry to enable Istio-controlled traffic to the external proxy.

Note that you must not create service entries for the external services you access through the external proxy, like wikipedia.org. This is because from Istio's point of view the requests are sent to the external proxy only; Istio is not aware of the fact that the external proxy forwards the requests further.

Cleanup

  1. Shutdown the [sleep]({{< github_tree >}}/samples/sleep) service:

    {{< text bash >}} $ kubectl delete -f @samples/sleep/sleep.yaml@ {{< /text >}}

  2. Shutdown the [sleep]({{< github_tree >}}/samples/sleep) service in the external namespace:

    {{< text bash >}} $ kubectl delete -f @samples/sleep/sleep.yaml@ -n external {{< /text >}}

  3. Shutdown the Squid proxy, remove the ConfigMap and the configuration file:

    {{< text bash >}} $ kubectl delete -n external deployment squid $ kubectl delete -n external configmap proxy-configmap $ rm ./proxy.conf {{< /text >}}

  4. Delete the external namespace:

    {{< text bash >}} $ kubectl delete namespace external {{< /text >}}

  5. Delete the Service Entry:

    {{< text bash >}} $ kubectl delete serviceentry proxy {{< /text >}}