Commit Branch Charm Config Update

Question

Description of change

This patch adds the crucial step of updating the charm configuration documents in the settings collection when a branch is committed.

The settings documents are all written in a single transaction so that we never get into a partially applied state.

This required adding a method to State in the settings module. I am not terribly fond of how this is done, but the generations requirements are exposing weaknesses in how settings is implemented in the state package.

QA steps

• export JUJU_DEV_FEATURE_FLAGS=generations.
• Bootstrap.
• juju deploy redis.
• juju branch test-branch.
• juju config redis password=pass --branch test-branch.
• (Optional) config redis password --branch master and verify there is no value.
• juju commit test-branch.
• juju config redis password shows "pass".

Documentation changes

None.

Bug reference

N/A

该提问来源于开源项目：juju/juju

Answer 1

Overwrite Settings Documents Upon Committing a Generation