Inspired by Sandi Metz’s BaRuCo 2013 presentation “Rules” (which you should watch if you haven’t yet) I started thinking about whether there were some rules that might be useful in the continuous delivery domain to “screen for cooperative types”.
I came up with these as a starting point:
- Check in everything – we’re used to putting source code in version control, but we’re often less good at configuration management. Do you control your test data? Your database scripts? Your operating system patch level? If not how can you be sure that the environment you provision tomorrow will be identical to the one you provisioned last week?
- Automate everything – “to err is human”, as the saying goes. Any manual process is susceptible to failures, so get rid of as many as you can. Some continuous delivery pipelines still have manual approval steps in them as part of the process, but the presence of the human is not functionally essential.
- Continuous != occasionally – the more we do something, the easier it gets. One of the reasons to do something continuously is to decrease the cost and remove the fear. If it “costs too much” to deploy often, then work on reducing the cost not reducing the frequency.
- Collaborate – people are not plug compatible. To get the most from the different people in the organisation we need to work together. For me, this was one of the major “innovations” of devops – no more ‘us’ and ‘them’, just ‘we’.
- One step at a time – it’s hard to do everything all at once, which is why we iterate in software development. Continuous delivery is no different – don’t expect everything to “just happen”.
Do these make sense to you? What essential ingredients have I missed?