A 0FS (Zero Footprint Service) should be self-contained at two levels.
Level 1 - download the file containing runtime, runtime engine, container, configs. Be able to untar and then start the service. Then as the system grows, easily move the 0FS to a new physical/virtual server by with tar, copy and untar. The only caveat is to use consistent user iDs and GUID's across systems.
This is not a new idea and in fact this is core to Unix and Linux of using small discrete programs chained together to do lots.
Level 2 - also package the operating system. This only became possible with Container technology.
Further, out of the box, a 0FS is per-configured with,
- Log Management (logs should rollover and compress)
- Secured following best practices
- Optimized trimming unnecessary fat for production use
- Documented
- Handle moving between environments (Dev, IST, QAT, Production ect...) without making changes during deployment.
Level 3 - cloud compatible.
With this model the level 2 package can register itself to route appropriately between promotion environments (IST, QAT and Production). Stateful data like logging is externalized. There are no unique identifiers so the package may be easily replicated.
Level 4 - CICD
Level 3 packages always built from recipes. Any change, even a simple config change happens in the receipe where upon a new Level 3 instance is rebuilt from scratch using the recipe.
Putting it in Practice,
Go to the 0FS main article to see the services currently made Zero Footprint through work on the BonsaiFramework.