10. What We’re Going to Cover
- Why you should script your builds
- Why you should use psake
- psake
- Tasks
- Parameters
- Conditionally Run Tasks
- Force Build Failure
- Other Useful commands
15. Why psake?
- Written in PowerShell Syntax
- Provides access the to whole .NET Framework
16. psake
- A Domain Specific Language to create build scripts
- Leverages PowerShell syntax
- Broken Down into
- Tasks
- Dependencies
- Parameters
- Properties
- Functions
Its release day and the team has gathered for their morning standup.
The tech lead Mark turns to the recently hired Sarah and says "Its tradition to have the newbie do the release so that they get familiar with the process.
Theres a README included in the solution and it has all the steps. Let me know when you're done so I can let the business know."
Now Sarah has been around the block a few times and has had no problems deploying software in the past so she says what the heck I'll give it a shot.
So she opens the readme and finds something that closely resembles this:
She needs to move files from one folder to another, Run the linter, Deploy stored procedures to the sql server, run tests and use the little orphan annie decoder pin to decipher the rest of the steps.
It all looks a bit challenging, but being the new member to the team she doesn't want to give up too soon. So....
The release has yet to go out, support is starting to get calls because for some reason the website now just points to a picture of Steves Cat.
Automation
Rarely is your application so simple that the default build button does everything you need it to do
You may have any number of tasks that may need to happen in any given order to fully build and run your application
For example on the project I am currently on, we must deploy stored procedures and functions, move files around and run entity framework migrations
We want these tasks to be done consistently before builds, psake allows us to automate this
As these tasks grow in numbers and complexity us humans get worse and worse at remembering all the tasks need to run before we can ship our code
Lets let our computers do what they’re best at which is following a set of instructions
Config as Code
Your build steps are captured as code instead of a readme
The build script is always checked in with your code and therefore kept up to date
If you ever need to revert changes to a prior commit, your build will still work
Eliminates the “works on my machine” adage
Every developer should be able to run the build and have it work the same
On our project we had developers saving cmd shortcuts to their desktops to run pre build scripts, now we use psake and every developer has access to the scripts
this gives us is consistent and repeatable builds. The build will work the same on every machine every time
Simplify your Deploy
With a build script you can take your deploy step down to a single command line command.
Releases become non events
No more huddling around orchestrating the deployment with your team, simply execute your deploy command
deploy independently from CI like Jenkins and TFS.
You can take your multi step build process down to a single one.
As mentioned in the slide before, if you need to revert back to a previous revision, that may require changing your whole build process,
With a build script, your build and deployment processes are always in line and up to date with your code
XML should be used to describe things not script things
Rake requires you to write Ruby code which can be foreign to dotnet developers
Rake also forces you to install Ruby gems which your standard windows box will not have
A lot of .NET developers may already have experience with powershell
psake is a domain specific language to create builds using a dependency pattern just like Ant, NAnt, Rake or MSBuild.
Tasks are the core of Psake, They are what you break your build steps down to
Recommend you handle your script like you would your code, with modularity
You can make these tasks depend on each other
You can pass parameters to theses tasks
These tasks can make use of properties
And because it is written in powershell you can write your own functions
Show the project, simple fizz buzz tdd with some fake acceptance tests
Demo building, cleaning, testing
Show dependencies
