* Add EventsGetter to KubeClient to enable to sending K8S events
* Add eventRecorder to the controller, initialize it and hand it down to cluster via its constructor to enable it to emit events this way
* Add first set of events which then go to the postgresql custom resource the user interacts with to provide some feedback
* Add right to "create" events to operator cluster role
* Adapt cluster tests to new function sigurature with eventRecord (via NewFakeRecorder)
* Get a proper reference before sending events to a resource
Co-authored-by: Christian Rohmann <christian.rohmann@inovex.de>
There is a possibility to pass nil as one of the specs and an empty spec
into syncConnectionPooler. In this case it will perfom a syncronization
because nil != empty struct. Avoid such cases and make it testable by
returning list of syncronization reasons on top together with the final
error.
Connection pooler support
Add support for a connection pooler. The idea is to make it generic enough to
be able to switch between different implementations (e.g. pgbouncer or
odyssey). Operator needs to create a deployment with pooler and a service for
it to access.
For connection pool to work properly, a database needs to be prepared by
operator, namely a separate user have to be created with an access to an
installed lookup function (to fetch credential for other users).
This setups is supposed to be used only by robot/application users. Usually a
connection pool implementation is more CPU bounded, so it makes sense to create
several pods for connection pool with more emphasize on cpu resources. At the
moment there are no special affinity or tolerations assigned to bring those
pods closer to the database. For availability purposes minimal number of
connection pool pods is 2, ideally they have to be distributed between
different nodes/AZ, but it's not enforced in the operator itself. Available
configuration supposed to be ergonomic and in the normal case require minimum
changes to a manifest to enable connection pool. To have more control over the
configuration and functionality on the pool side one can customize the
corresponding docker image.
Co-authored-by: Felix Kunde <felix-kunde@gmx.de>
Christian Rohmann
Dmitry Dolgov
Felix Kunde