[DPE-10203] fix(async-replication): reference the offer secret by id on the consumer - #1838
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…he consumer The standby/consumer side read the shared offer secret with a fixed Juju label, which registers a consumer-side alias under that label. Juju keeps the alias reserved even after the remote secret is force-removed during a dead-DC teardown, so a former standby is left carrying a stale alias it can neither read nor release. The owner-side OFFER_SECRET_LABEL split already breaks the promotion deadlock, but the consumer alias remains an avoidable latent hazard whose safe reuse depends on unverified Juju relabel behaviour. Referencing the secret purely by the id already published in the relation databag — as the MySQL async-replication charm does — means no consumer alias is ever registered and nothing can go stale, closing the DPE-10203 failure class on the consumer side too. This is backward compatible: the id is already present in primary-cluster-data and no peer depends on the alias existing. Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
…on reads
After a dead-DC teardown the remote app/unit databag on the dying cross-model
async relation raises ModelError ("permission denied") on any read. Only
_get_primary_cluster was guarded; the sibling reads were not, so they crashed the
hooks that keep a promoted cluster reconciling — replication-offer-relation-joined
and database-peers-relation-changed both died, leaving units wedged in error and
blocking re-replication to a fresh cluster.
Route every async-relation databag read through a shared _safe_databag_get helper
(and a shared _remote_unit_addresses for the two identical endpoint list
comprehensions) that treats an unreadable databag as key-absent, matching the
existing _get_primary_cluster behaviour, so the teardown always reconciles instead
of crashing.
Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
ops implements Application.planned_units() via the goal-state hook command, which
fails ("saas application ... not found") while a cross-model SAAS force-removed
during a dead-DC teardown still lingers in goal-state. Every caller — the _patroni
property construction, the degraded-status check, the synchronous-node count and the
backups pre-checks — crashed its hook, cascading through the _patroni property to
wedge the promoted cluster and block re-replication to a fresh cluster.
Route them through a single guarded _planned_units property that falls back to the
current unit count when goal-state is unavailable, so hooks reconcile instead of
crashing (DPE-10203 Issue B).
Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
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Merge the fixes branch after its sync with 16/edge (single-kernel lib 16.3.5 update_config adoption #1849 among 28 commits), so the stacked PR's diff and CI run against the current base. The charm-side sync moved the DPE-10203 stale-standby fix to the new update_config seam; this merge carries that over. The stacked branch's own planned-units regression tests are kept at the tail of the test file, replacing the worker-config tests the upstream refactor deleted. Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
…s' into dpe-10203-consumer-secret-by-id Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
2 tasks
Pull the stale-counter reconciliation fix (clear even after a new relation forms) so the stacked PR validates against the current base. Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
The consumer now references the offer secret purely by id, so the legacy shared label is no longer attached anywhere by this charm — keeping the constant "only to assert we never reintroduce it" was dead weight in production code for a test-only concern. The tests that guard against reintroduction use the literal string instead, the same black-box approach the integration test already takes. The owner-side OFFER_SECRET_LABEL stays: it is the owner's stable handle to its own secret across hooks and survives the loss of the relation data that carries the published id — exactly what a dead-DC teardown destroys. Signed-off-by: Marcelo Henrique Neppel <marcelo.neppel@canonical.com>
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Superseded by #1913 — the consumer-by-id change is included there; the label constants are gone entirely (labelless design). |
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Issue
DPE-10203 (stacked on #1837): the consumer/standby side of async replication fetched the offer's shared secret with
get_secret(id=..., label=SECRET_LABEL), registering a consumer-side alias under the legacy shared label. Juju keeps that alias reserved even after the remote secret is gone, which is the other half of the post-dead-DC deadlock: a former standby that is later promoted can neither read nor create a secret under that label.Solution
Consumer-side and robustness fixes:
SECRET_LABELconstant from production code: nothing attaches it anymore, and the tests that guard against reintroducing it use the literal string (the integration test already did, to stay black-box);planned_units()fails on the goal-state read (which errors while a force-removed SAAS churns), keeping the_patroniproperty usable in every hook.The owner-side label (
OFFER_SECRET_LABEL) stays by design: the owner needs a stable handle to its own secret across hooks, one that survives the loss of the relation data carrying the published id — exactly what a dead-DC teardown destroys.Checklist