9.2.5.4 Dev Secret Handling
A focused guide to Dev Secret Handling, connecting core concepts with practical Docker and container operations.
Dev secret handling refers to the practical approach for managing sensitive values during local development, balancing genuine security hygiene against the convenience needed for a smooth day-to-day development workflow, typically using local, gitignored secret files rather than a production-grade secret management system.
A Practical Local Development Approach
Local secret files, excluded from version control, provide development-time values for whatever a service's secrets declaration expects.
secrets/
db-password.txt
secrets/
This .gitignore entry ensures the actual secret file content never gets committed, even though the Compose file referencing it (which contains no actual sensitive value itself) can be safely committed.
Why Development Secrets Should Still Never Be Genuinely Sensitive Production Values
Even in a local-only context, development secret files should contain development-appropriate placeholder values, never actual production credentials, since a local machine is generally a less controlled environment than wherever production secrets are properly managed.
devpassword123
A clearly development-oriented value like this, rather than an actual production password, ensures no genuinely sensitive value is ever at risk even if a local secret file were somehow mishandled.
Providing a Template for Other Developers
A template file, safely committed to version control, documents exactly what secret files a project expects without containing any actual sensitive content itself.
secrets/db-password.txt.example
cp secrets/db-password.txt.example secrets/db-password.txt
A new developer copies and customizes this template, quickly setting up the expected local secret files without needing separate documentation explaining what's required.
Why Dev Secret Handling Matters
A sensible, lightweight approach to development-time secrets — local, gitignored files containing development-only placeholder values, with a committed template documenting what's expected — provides a reasonable balance between security hygiene and development convenience, without requiring full production-grade secret management infrastructure just for local development purposes.