Using Envoy as a Basic Front Proxy

Requirements

An installation of GetEnvoy. You can find instructions on how to install GetEnvoy here.

Instructions

In this tutorial we are going to use Envoy as a basic front proxy to Google and Bing. When we hit Envoy with the host header google.com it will proxy our request to www.google.com and when we hit Envoy with the host header bing.com it will proxy our request to www.bing.com.

  1. Retrieve static configuration for Envoy to use.

    $ curl -L https://getenvoy.io/samples/basic-front-proxy.yaml > basic-front-proxy.yaml

  2. Investigate the static configuration file.

    $ cat basic-front-proxy.yaml

    The YAML contains comments explaining the behavior of the relevant sections.

  3. Run Envoy using the static configuration.

    $ getenvoy run standard:1.11.1 -- --config-path ./basic-front-proxy.yaml

  4. Open a new shell and cURL Envoy with google.com as the host header.

    $ curl -s -o /dev/null -vvv -H 'Host: google.com' localhost:15001/

    Connected to localhost (127.0.0.1) port 15001 (#0)
> GET / HTTP/1.1
> Host: google.com
> User-Agent: curl/7.54.0
>
< HTTP/1.1 200 OK
< server: envoy
< set-cookie: 1P_JAR=2019-06-05-08; expires=Fri, 05-Jul-2019 08:30:07 GMT; path=/; domain=.google.com
{ [3538 bytes data]

    In this abbreviated response you can see that we made it to google.com as it is setting a cookie. If you want to see the full HTTP response body remove the -s -o /dev/null flags.

  5. cURL Envoy with bing.com as the host header.

    $ curl -s -o /dev/null -vvv -H 'Host: bing.com' localhost:15001/

    ...
Connected to localhost (127.0.0.1) port 15001 (#0)
> GET / HTTP/1.1
> Host: bing.com
> User-Agent: curl/7.54.0
>
< HTTP/1.1 200 OK
< server: envoy
< set-cookie: SRCHD=AF=NOFORM; domain=.bing.com; expires=Mon, 29-Jun-2020 08:30:01 GMT; path=/
<
{ [279 bytes data]

    In this abbreviated response you can see that we made it to bing.com as it is also setting a cookie. If you want to see the full HTTP response body remove the -s -o /dev/null flags.

  6. Check the access logs in the shell running Envoy.

    [2019-06-05T08:30:01.145Z] "GET / HTTP/1.1" 200 - 0 111162 374 135 "-" "curl/7.54.0" "c1aeafd2-dcd9-4070-80fd-f8f4f6bd1e85" "www.bing.com" "13.107.21.200:80"
[2019-06-05T08:30:07.799Z] "GET / HTTP/1.1" 200 - 0 12426 64 60 "-" "curl/7.54.0" "0c8ce45d-e99e-4ddc-9cc4-06d75d81e610" "www.google.com" "216.58.213.4:80"

    The access logs confirm that we have made two successful requests: one to www.google.com and the other to www.bing.com. To find out more about the default format of the access logs and information on the other fields present, check out the Envoy documentation.