Implementing CI/CD for Legacy

Applications

CenturyLink

• Telecommunications company formed by the merger of

USWest, Embarq, and CenturyTel

• 32 States

• +47,000 Employees

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Before

• Many manual steps and hand offs

• Poorly defined ownership

• Properties and environment definitions co-mingled

• All or nothing build, install, deploy

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Challenges

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• Replace existing, but don’t lose any capabilites

• De-coupling code compilation from environment creation

• Replacing runtime environment creation

• You’re not the boss of me

Solutions

• Decompose rigid relationships when possible

• Configuration management

• Identify constraints

• Automation

• Minimize constraints to speed adoption

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• “Measure twice cut once”

• Transparency enables faster RCA and shorter MTTR

• Complexity vs. Complicated

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After

• Self Service for Developer environments, approval

based for environments with strict Change Control

• Tools and Methodology align to enable clear ownership

• Ability to push features through updates to only the parts

that are changing

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Things to remember

• Validate outcomes of each change

• Do not settle for “It says it is running”

• Test and then test some more

• Keep learning

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