The Art of Deployment.

Some days ago Matt and I had to deploy a rails application. This was an application that both Matt and I had no idea existed about 2 days before we ended up deploying it so we were quite looking forward to it on a very rainy wednesday! (Why does it always rain when I am deploying???)

A day before Matt had tried to deploy the application to staging to see whether we could test it out before production got her hands on it, but the staging environment had not been puppetised for this particular app. When we realised that deployment to staging might not possible, we spoke to our resident friendly release manager Aaron and laid out several plans. The first action was for me to test the shi^H^H^H hell out of the app locally (with production data) as much as I could while Matt tried his best to puppetise staging.

Early wednesday morning, I managed to test the app completely and ensured that the changes some awesome developer *cough* had made worked. Matt had also finished his spike with staging but no goodness. So we both looked at each other and decided to deploy it, to production herself.
Four hours, a plate of sushi and a coffee later, the thing had been deployed and we had ensured that it worked in production and informed the relevant parties!

From this all, I have learnt a few things:

1. Even though we both knew nothing about the app, I ensured that Matt was involved in it from the very beginning, and it helped a great deal. Springing deployment surprises on OPS is not cool and helps no one, least of all you as a developer. JIRA and Zendesk are cool, but nothing, nothing will actually substitute going over and talking to your fellow OPS people.

2. Puppet. Puppet is cool. The fact that we could quickly spike things in staging and decide whether to deploy there or not was simply because puppet allowed us that level of automation. Invest of in such tools, whether they be puppet, chef or babushka

3. We did not panic and delay the release when we found out that we could not test it in staging. We sat with Aaron and figured out the risks of each scenario and associated rollbacks. We did as much testing as we could do before hand and then went ahead with the deployment. To quote my colleague Jon Eaves, “Fear is the mind Killer”.

Above all, it was great fun to work with Matt, and deploy something along the way :). This has made me realise that software development, and deployment, is amazingly rewarding when done with awesome people.