The importance of build numbers

If I were to make a prediction, I would say that build numbers are something that are rarely treated as being important in the agency world of web development. That’s not to say milestone releases aren’t given names like “Phase 2”, “August Release” or a major feature name, but every build / release of a project in between, I’d sense largely have build numbers either ignored or never created.

It’s also easy to see why, after all it’s not like we’re producing software that’s going out to the masses to be installed. The solution is essentially just ending up having 1 install on a set of servers. When a new version is built, that replaces everything that came before it and if a bug is found we generally roll forward and fix the bug rather than ever reverting back.

Why use build numbers?

So when we’re constantly coding and improving applications in an agile world why should we care about and use build numbers?

To put it quite simply its just an easy way to identify a snapshot of code that could have actually have been built and then released to a server. This becomes hugely useful in scenarios such as:

  • A bug being reported by an end user
  • An issue being identified by some performance monitoring
  • An issue being picked up in some functionality further on from the site. e.g. in an integration

Without build numbers the only way to react to these scenarios is to look at commit dates in source control or manual release notes that may have been created to try and work out where an issue may have been created and what changed at that time. If the issue had subsequently been fixed you also can’t really give a version description when it was fixed other than a rough date.

Other advantages of build numbers can include:

  • Being able to reference a specific version that has been pen tested
  • Referencing a version that’s been tested with integrations
  • Having approval to release a specific version rather than just the latest on master
  • Anywhere you want to have a conversation referencing releases

Build numbers for deploys

The first step to use build numbers and with the rise in CI, possibly the one thing most people are doing is to start creating build numbers via a build server. By using any type of build server you will end up with build numbers. This instantly gives you a way to know when a build was created and what commits were new within the build.

Start involving an automated deployment setup either using your build server or with other tools like Octopus Deploy and you will now start to get a record of when each build was deployed to each server.

feature-1

Now you have an easy way to not only reference what build was on each environment and when through the deploy history, but also a way to see what went into a build through the build servers change log.

Tag builds in source control

Being able to see the changes that went into each build on your build server is all very good, but it’s still not an ideal situation for finding the exact code version a build relates to.

Thankfully if your using Team City it’s really easy to set it up to create a tag in your source control with each build number. Simply go to the build features section of your projects configuration and add a feature called “VCS Labeling”. This is a step that happens post build in the background and will create a tag in source control including the build number. It has lots of other configuration options, so if you need different tag formats for different branches its got you covered.

If your using GitHub once this is turned on you will be able to see a list of all the tags in the releases section.

GitHub Releases Screen

Update Assembly info

Being able to identify a build in source control and view a history of what should have been on a server at a particular time is all very good, but its also a good idea to be able to easily identify a build for a published version of code. That way just by looking at the code on a server you can tell which build version it is, and not rely on your deployment tool to be correct.

If your using Team City this also also made super simple through a build feature called “Assembly info patcher”. When using this the build number will automatically get patched in without having to edit AssemblyInfo.cs.

Conclusion

By following these tips you will now be able to identify a version by looking at the published code, see a history of when each version was not only built but also released to each envrionment and also have an easy way to find the exact source for that build.

The build number can then be used in any conversations around when a bug was introduced and also be referenced in release notes so everyone can keep track of what versions included what fix’s in a simple to understand format.

What’s your source control strategy?

I’ve seen companies that have no form of source control, companies using backups as source control, people still using Source Safe along with a whole bunch of actual good source control solutions such as Git and SVN. But when I say what’s your source control strategy I don’t mean what tool are you using, I mean how are you using it.

Checking you’re code into source control adds many benefits such as merging, versioning, reverting etc, but to get the most out of it you really need a strategy to define how you will use it. There is no one right way and the strategy you use ultimately depends on your team size and what you are doing.

Here are a few example strategies:

The didn’t know about a strategy approach

You’ve got a source control solution, you’re regularly checking your code in but you’ve never made a branch.

This is actually quite common. Everyone is developing against the same branch, you’ve got all the benefits of seeing who changed which piece of code, you can revert when you need to revert and when you do an update there’s some help with merging.

What you don’t get though is the ability to have work happening in parallel and one being released before the other. If you needed to do a release either you have to have a way of hiding the unfinished updates as the code is pushed to live or some way of reverting just those bits.

A branch for every feature

The other extreme is to have all development work happen on a new branch. When it’s ready to be release the code is merged back into the trunk and then released (plus some testing along the way).

The advantages of this are your trunk is always the same as what’s on live meaning emergency fix’s can be made without trying to find the last release in the source control history. Developers can also work separately without stepping each other toes and can release.

However with more than one development happening at the same time, whoever merges second could have a big job on their hands. All that branching is also going to be time consuming.

Updating branches often

So you’re using branches and to avoid a tricky merge are keeping the branch up to date regularly, possibly daily. Anyone who’s tried to merge a feature branch after 3 months of development can testify that it doesn’t always go smoothly and can take some time.

Only updating the branch at the end

You’ve decided to accept the large merge at the end of the project. You don’t like it but figure all those small merges during the project actually add up to more time than one big one at the end. You can then also concentrated on getting the feature built without the regular merge distraction.

A tag for each release

If you’ve ever needed to find a previous release and only have the history to go on it can be hard. If there’s no comment that says release to live you are basically guessing based on release date and last commit.

A tag is basically the same as a branch and if its part of your release plan, you’ve got a good way of finding each release to live.

A branch for live, a branch for dev

In this setup you have a live branch that always match’s what’s on the live site. There’s less need for tags as commits to this branch are normally also a release to live, and because the branch is always in sync with live, emergency fix’s are taken care of.

The downside with this approach is everyone is working on the dev branch, so exceptions should be made and feature branches used when it makes sense.

So…

So there are some of the strategies I’ve come across, but there will be plenty more. What you do ultimately relates to what kind of work you do, how frequently you release and what kind of team size you have. But the one thing you must do with all of them is make comments on each commit. If you don’t then source control becomes virtually useless.