Migrating a system as a whole

Changing a system’s platform is rarely just about the operating system.

Together with the application, its data, configuration, integrations with other systems and the way those integrations authenticate all have to move. If any of these is left behind, the system may run in the new environment without doing its job.

I carried out the migration according to four principles:

• Restoring the system’s dependencies — identifying all the elements the system needs to work — data, configuration, integrations and authentication — not just the application itself.
• Reproducible environments — configuration described and deployed automatically, so every environment can be prepared in the same, repeatable way.
• Restored data — moving the data together with the application by restoring it in the new environment from backup.
• Secure integration authentication — secrets kept outside the application configuration, with integrations using machine authentication.

I carried out a migration covering the change of system platform and application version, the restoration of data and getting the integrations and their authentication working again in the new environment.

I designed deployment and configuration-management automation that lets every environment of the system be prepared in a repeatable way. Integrations authenticate with machine credentials through a secrets store.

Value: the system runs in the new environment with its data, integrations and authentication, and the configuration of its environments is repeatable through automation.