All terms
Glossary
Container
Also: Docker
An application together with its dependencies in a self-contained package that runs the same everywhere.
The benefit is reproducibility: what runs locally runs identically in staging and production, because runtime and libraries travel with it.
For legacy systems containers are often the first sensible step, because they unify operations without changing the application.
How you notice it
- It works locally but not on the server.
- Library versions differ between environments.
- An old system needs to move without being changed.
Frequently asked
Should the database run in a container too?
In development yes, in production rarely. State in a container means state that disappears on restart unless you are careful. In production a managed database service is nearly always the better answer.