What

In these onboarding stories you will be using the proxy app a lot. Basically every story, so let’s get familiar with it. Proxy is little golang app that is surprisingly powerful. In this story we are going to test out some of its functions.

Often with container to container (c2c) networking stories, you need an app to make a request to another app. Or you want to time how long DNS resolution (turning a URL into an IP address) is taking. You could do this with cf ssh and then running curl or dig (and we will in later stories!), but the proxy app was created so we didn’t have to do that. It has different endpoints that will …proxy… traffic to a given destination and that will do DNS resolution of a URL you give it, among other things. Using proxy gives a better mirror how users use our product.

Let’s check out proxy’s power.

How

📝 Push a proxy app

  1. Clone the cf-networking-release repo 
    git clone https://github.com/cloudfoundry/cf-networking-release
  2. Go to the proxy app 
    cd ~/workspace/cf-networking-release/src/example-apps/proxy
  3. Push the app and name it appA 
    cf push appA

When you push an app, an HTTP route is automatically created. Let’s call this route PROXY_ROUTE.

🤔 Use the proxy app

Skim through proxy’s README and look at all the endpoints that it has.

NOTE: you may need to use the -k option for these curl commands, if you get a certificate error.

  1. Use the /dig/URL_TO_DIG endpoint to do DNS resolution for google.com.
  2. Use the /digudp/URL_TO_DIG endpoint to do a DNS resolution for google.com over udp. Dig usually uses tcp. This is a great way to test if udp traffic is working. (What are tcp and udp? Check out the resource below!)
  3. Use the /proxy/URL endpoint to send traffic to neopets.com.
  4. Use at least two more endpoints.

Expected Outcome

Now you know the power of proxy!

Resources