Use Case: Create array specification for dockerd configuration file (daemon.json)

Summary

• Scope: spec
• Level: Developer Goal
• Actors: Dev-Ops Engineer
• Brief: This use case introduces an array specification for a part of the dockerd configuration file (daemon.json).

Scenarios

• Precondition: The Dev-Ops Engineer has a working setup for docker for and the daemon dockerd.
• Main success scenario:
  • The Dev-Ops Engineer wants to write a specification for the storage options in the dockerd configuration file.
  • The array specification configuration key is storage/opts/#.
  • The configuration uses array/min and description as metakeys.
  • The array is defined by the wildcard character #.
  • The keys are all stored for the spec namespace.
• Alternative scenario:
  • Define the storage type with an underline specification.
  • The array specification configuration key is storage/opts/_.
  • The configuration uses array/min and description as metakeys.
• Error scenario:
  • Wrong metakeys are used (yielded as error to the user).
• Postcondition: The keys are all stored for the spec namespace.
• Non-functional Constraints: None.

Example

The storage options configuration for the dockerd could look like:

[storage/opts/#]
meta:/array/min = 0
meta:/description = Storage driver options

For the full specification of the dockerd configuration file see dockerd-spec.