Call Patroni API /config in order to set special options that are
ignored when set in the configuration file, such as max_connections.
Per https://github.com/zalando-incubator/postgres-operator/issues/297
* Some minor refacoring:
Rename Cluster ManualFailover to Swithover
Rename Patroni Failover to Switchover
Add more details to error messages and comments introduced in this PR.
Review by @zerg-junior
After an unsuccessful initial cluster sync it may happen that the
cluster statefulset is empty. This has been made more likely since
88d6a7be3, since it has introduced syncing volumes before statefulsets,
and the volume sync mail fail for different reasons (i.e. the volume has
been shrinked, or too many calls to Amazon).
Some special patroni postgresql parameters, like max_connections,
should reside in the bootstrap.dcs.postgresql.parameters section
to come into effect.
When there is an error happening upon deletion of the Kubernetes object
belonging to the cluster being removed, it makes no sense to abort the
deletion: the manifest will be removed anyway, therefore all the objects
after the one we aborted at will stay forever.
Do not use statefulset number of pods to figure out running ones
for volume resizing, since the statefulset pointer could be nil.
Instead, look at the actual running pods.
Avoid sharing pointers to the same spec data between the informer
and the clusters. The only catch is that the error field is cleared
during deepcopy, since it is an interface that may contain private
fields that cannot be copied, however, the error is only used when
the manifest is parsed and before it is queued, therefore, we never
refer to that field in the cluster structure.
987b434 introduced a new function that modifies the cluster spec in
memory before the cluster processes it. Unfortunately, the instance
being modified appeared to be the one stored internally in the
PostgresInformer, resulting in those modifications to be propagated with
futher cluster events and producing update loops in some occasions.
This commit makes sure we copy the spec before putting it into the
clusterEventQueues.
* Depreate old LB options, fix endpoint sync.
- deprecate useLoadBalancer, replicaLoadBalancer from the manifest
and enable_load_balancer from the operator configuration. The old
operator configuration options become no-op with this commit. For
the old manifest options, `useLoadBalancer` and `replicaLoadBalancer`
are still consulted, but only in the absense of the new ones
(enableMasterLoadBalancer and enableReplicaLoadBalancer).
- Make sure the endpoint being created during the sync receives proper
addresses subset. This is more critical for the replicas, as for the
masters Patroni will normally re-create the endpoint before the
operator.
- Avoid creating the replica endpoint, since it will be created automatically
by the corresponding service.
- Update the README and unit tests.
Code review by @mgomezch and @zerg-junior
* Sanity checks for the cluster name, improve tests.
- check that the normal and clone cluster name complies with the valid
service name. For clone cluster, only do it if clone timestamp is not
set; with a clone timestamp set, the clone name points to the S3 bucket
- add tests and improve existing ones, making sure we don't call Error()
method for an empty error, as well as that we don't miss cases where
expected error is not empty, but actual call to be tested does not
return an error.
Code review by @zerg-junior and @Jan-M
* Improve the pod moving behavior during the Kubernetes cluster upgrade.
Fix an issue of not waiting for at least one replica to become ready
(if the Statefulset indicates there are replicas) when moving the master
pod off the decomissioned node. Resolves the first part of #279.
Small fixes to error messages.
* Eliminate a race condition during the swithover.
When the operator initiates the failover (switchover) that fails and
then retries it for a second time it may happen that the previous
waitForPodChannel is still active. As a result, the operator subscribes
to the former master pod two times, causing a panic.
The problem was that the original code didn't bother to cancel the
waitForPodLalbel for the new master pod in the case when the failover
fails. This commit fixes it by adding a stop channel to that function.
Code review by @zerg-junior
Avoid showing "there is no service in the cluster" when syncing a
service for the cluster if the operator has been restarted after
the cluster had been created.
Compare pods controller revisions with the one for the statefulset
to determine whether the pod is running the latest revision and,
therefore, no rolling update is necessary. This is performed only
during the operator start, afterwards the rolling update status
that is stored locally in the cluster structure is used for all
rolling update decisions.
* Remove 'team' label from the statefulset selector.
I was never supposed to be there, but implicitely statefulset
creates a selector out of meta.labels field. That is the problem
with recent Kubernetes, since statefulset cannot pick up pods
with non-matching label selectors, and we rely on statefulset
picking up old pods after statefulset replacement.
Make sure selector changes trigger replacement of the statefulset.
In the case new selector has more labels than the old one nothing
should be done with a statefulset, otherwise the new statefulset
won't see orphaned pods from the old one, as they won't match the
selector.
See https://github.com/kubernetes/kubernetes/issues/46901#issuecomment-356418393
Oleksii Kliukin
Sergey Dudoladov
zerg-junior
Manuel Gómez
Oleksii Kliukin