creating a maintainable software ecosystem jeremy d. miller november 27th, 2007
TRANSCRIPT
Creating a Maintainable Software Ecosystem
Jeremy D. Miller
November 27th, 2007
Sharpen the Saw!
“Give me six hours to chop down a tree and I will spend the first four sharpening the axe. ”
- Abraham Lincoln
The 10X Development Ecosystem
• It’s the code, yes, but it’s also the ecosystem• What’s the Ecosystem?
Source Control Build scripts Continuous Integration infrastructure Test automation Database scripts and migrations
Themes
• Eliminating Friction• Go fast, go safe• Knowing where things are• Ratcheting up the Feedback Loops• Favoring automation over formal processes
Story Wall – Start of the Iteration
Not Started In Progress TestingCustomer Review
Done, Done, Done
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Story Wall – Iteration Halfway Point
Not Started In Progress TestingCustomer Review
Done, Done, Done
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Dude, it worked on my box!
• You can’t work if you can’t run the system• The build script should lay down the development
environment• Build script == environment documentation• 3rd Party tools and open source libraries in source control• Propagate new environmental dependencies ASAP!• Retrofit Legacy Code with automated build scripts• README.txt
I grabbed the latest code, but it’s broken!
• Lean on Continuous Integration Compile Lay down the environment Unit tests
• Clean Build Server• It’s all about feedback
The Check-In Dance1. Don’t check into or out of a broken build
2. Update your code from source control
3. Merge any conflicts
4. Run the build locally
5. If the build is successful, commit your changes
6. Monitor the build server for success or failure
7. If the build breaks, fix it!
8. Never leave a build broken overnight
Are you sure you have the right code?
• Single Source Point• Tag successful builds• Embed the build number in compiled assemblies• NEVER build and deploy from a developer environment• Repeatable, traceable builds• Promote code by build number• Communicate issues, fixes, and feature completion by build
number
• Demo: Labeling builds with CruiseControl.Net
Right code, wrong database!
• Treat all database code as just more code• DBA’s play by the same rules• One database per developer and environment
Demo: “database.build”
• If it changes together, it builds together• Propagating database changes must be reliable, easy, and
friction free Enable continuous design and incremental delivery Synchronize development environments Demo: Migrations
It’s a five minute fix…
• …but it’ll take a day to migrate the code• You will make mistakes• Cycle faster between development and testing• Automate anything that moves• Create deployment packages on successful Continuous
Integration builds• Use a no touch deployment to testing
Did it get installed correctly in test?
• Environment tests• Demo: Self-testing configuration with StructureMap• Synthetic transaction
What would it take for last minute changes to be safe?
• Comprehensive automated test coverage• Feedback cycle• Fast build, slow build
Demo: Cascading build
• Prerequisites for Test Automation If the tests haven’t been run, how do you know your code still works? Getting the latest code to the test environment Watch for file collisions Building a set of test data
My goodness, we’ve got a lot of code!
• Multiple source control repositories and builds• Propagating dependent libraries
Manual or Automatic?
• Shared resources
Are you pointed at the right server?
• Demo: Configuration profiles with StructureMap
Sharpening the Saw
• “I don’t have time to sharpen my saw, I’m too busy chopping wood!”
• Balancing technical improvements versus new business features
• Make it easy to do the right thing• No artificial process restrictions• “We’ve just got to get the project out the door”
Last Thoughts
• Project automation is a team effort Watch the Low Truck Number effect
• Use project automation as an enabler• Automate anything repetitive• Automate away friction• Look to automate bookkeeping activities• Feedback is everything
Frequent check-ins Keep the build lean and mean Run the automated tests frequently
