Deploy different versions of a go application in a real environment and visualize their performance in datadog thanks to expvar metrics.

1. Create the different versions of the app you want to test and put them into the bin folder. For example, if you're using dep, modify the constraints in the Gopkg.toml, dep ensure and then go build your app.

2. Rename your binaries by following the naming convention APP-VERSION. For example, nicky-develop, where nicky is the name of the app and develop the name of the branch.

3. If you have n versions to compare, provide n hosts in the hosts list. The binaries will be deployed on them.

4. Run the script with ./main.sh.

5. Visualize your metrics in the datadog app.

You should only provide hosts that come from the same availibility zone for better results in the comparison. You can use the datadog hostmap to visualize the hosts running your app per availibility zone. Then inspect the page and go to network tab, click on overview? and save rows as a global variable. Then open the chrome js console and type:

hosts = temp1.filter(row => row.tags_by_source["Amazon Web Services"][0].includes("us-east-1a")).map(row => row.display_name)
hosts.forEach(h => console.log(h))

This way you'll be able to provide only the hosts for a given availibility zone.