DPE-2206 In-place upgrade support

[paulomach]

In place upgrades for mysql-k8s.

Usage upgrade lib with k8s adaptations. Much like zookeeper PR#71.

Solution

Implemented upgrade module.
Depending on dp-libs PR#81

TODO

• replicate mysql lib modifications to vm
• Documentation
• Rollback documentation

Manual Testing (with same local built charm)

Instructions (happy path):

git clone [email protected]:canonical/mysql-k8s-operator.git
cd mysql-k8s-operator
git checkout feature/upgrades

charmcraft pack
# deploy local charm
juju deploy ./*.charm --trust --resource mysql-image=ghcr.io/canonical/charmed-mysql@sha256:017605f168fcc569d10372bb74b29ef9041256bd066013dec39e9ceee8c88539 -n 3

# After units settle, run pre-upgrade-check to build update-stack.
# This will change primary to unit 0 if not already
juju run-action mysql-k8s/leader pre-upgrade-check --wait

# inspect update relation data, should have `upgrade-stack` like `'[0,1,2]'`
juju show-unit mysql-k8s/0|yq '.*.relation-info[]|select(.endpoint=="upgrade")'

# refresh command - we are updating to the same charm, which will pass version checking
juju refresh --path ./*.charm mysql-k8s

# at this point just the highest ordinal unit will be updated.
# after successful upgrade, run:
juju run-action mysql-k8s/leader resume-upgrade --wait

# which will trigger auto rollout for upgrading the other units.

[taurus-forever]

Great work!

[taurus-forever]

blessed.