ceph-csi

Description

This is a subordinate charm of kubernetes-master, deployed as part of the Charmed Kubernetes and enables Kubernetes cluster to use Ceph as a storage. Currently supported storage options are ceph-xfs and ceph-ext4 with cephfs being work in progress.

Note: This charm creates various Kubernetes resources, including pods. Therefore it requires kubernetes-master to run in privileged mode (config option allow-privileged=true)

Usage

Since this charm is not published in charmstore yet, it needs to be built from source.

$ charmcraft pack  # This will produce `ceph-csi.charm`

As this charm has no standalone functionality, we'll need Kubernetes and Ceph cluster first.

$ juju deploy charmed-kubernetes
$ juju config kubernetes-master allow-privileged=true
$ juju deploy -n 3 ceph-mon
$ juju deploy -n 3 ceph-osd
$ juju add-relation ceph-osd ceph-mon

Once the deployment settled, We can add ceph-csi

$ juju deploy ./ceph-csi.charm
$ juju add-relation ceph-csi kubernetes-master
$ juju add-relation ceph-csi ceph-mon

Warning: Removal

When ceph-csi charm is removed, it will not clean up Ceph pools that were created when relation with ceph-mon:client was joined. Interface of ceph-mon:client does not seem to offer a "removal" functionality. If you wish to remove ceph pools, use delete-pool action of ceph-mon unit.

Developing

Create and activate a virtualenv with the development requirements:

virtualenv -p python3 venv
source venv/bin/activate
pip install -r requirements-dev.txt

Testing

The Python operator framework includes a very nice harness for testing operator behaviour without full deployment. To execute unit tests, run:

$ tox -e unit

This charm contains also functional tests which fully deploy ceph-csi charm along with kubernetes and ceph cluster to test its functionality in a real environment. There are a few ways to run functional tests

$ tox -e func                          # Deploys new juju model and runs tests
$ tox -e func -- --model <model_name>  # Runs tests against existing model
$ tox -e func -- --keep-models         # Does not tear down model after tests are done (usefull for debuging failing tests )

NOTE: If the environment which runs functional tests is behind a http proxy, you must export TEST_HTTPS_PROXY environment variable. Otherwise Kubernetes might have problem fetching docker images. Example: