The DataStax Kubernetes Operator for Apache Cassandra®. This repository replaces the old datastax/cass-operator for use-cases in the k8ssandra project. Some documentation is still out of date and will be modified in the future. Check k8ssandra/k8ssandra for more up to date information.
To create a full featured cluster, the recommend approach is to use the Helm charts from k8ssandra. Check the Getting started documentation at (k8ssandra.io)[https://k8ssandra.io/docs].
A more custom approach is to use Kustomize as described in the following sections if you wish to use cass-operator only. If updating from previous version, please see Upgrade instructions section first.
The operator can be installed in a namespace scoped settings or cluster wide. If installed cluster wide, one can define which namespaces (or all) are watched for CassandraDatacenter objects.
Default installation is simple, the kubectl will create a namespace cass-operator and install cass-operator there. It will only listen for the CassandraDatacenters in that namespace. Note that since the manifests will install a Custom Resource Definition, the user running the commands will need cluster-admin privileges.
Default install requires cert-manager to be installed, since webhooks require TLS certificates to be injected. See below how to install cert-manager if your environment does not have it installed previously.
kubectl apply -k github.com/k8ssandra/cass-operator/config/deployments/defaultIf you wish to install it with cluster wide rights to monitor all the namespaces for CassandraDatacenter objects, use the following command:
kubectl apply -k github.com/k8ssandra/cass-operator/config/deployments/clusterAlternatively, if you checkout the code, you can use make deploy to run Kustomize and deploy the files.
This will deploy the operator, along with any requisite resources such as Role, RoleBinding, etc., to the cass-operator namespace. You can check to see if the operator is ready as follows:
$ kubectl -n cass-operator get pods --selector name=cass-operator
NAME READY STATUS RESTARTS AGE
cass-operator-555577b9f8-zgx6j 1/1 Running 0 25hUpdates are supported from previous versions of k8ssandra/cass-operator. If upgrading from versions older than 1.7.0 (released under datastax/cass-operator name), please upgrade first to version 1.7.1. The following instructions apply when upgrading from 1.7.1 to 1.8.0.
Due to the modifications to cass-operator’s underlying controller-runtime and updated Kubernetes versions, there is a need to do couple of manual steps before updating to a newest version of cass-operator. Newer Kubernetes versions require stricter validation and as such we need to remove preserveUnknownFields global property from the CRD to allow us to update to a newer CRD. The newer controller-runtime on the other hand modifies the liveness, readiness and configuration options, which require us to delete the older deployment. These commands do not delete your running Cassandra instances.
Run the following commands assuming cass-operator is installed to cass-operator namespace (change -n parameter if it is installed to some other namespace):
kubectl -n cass-operator delete deployment.apps/cass-operator
kubectl -n cass-operator delete service/cassandradatacenter-webhook-service
kubectl patch crd cassandradatacenters.cassandra.datastax.com -p '{"spec":{"preserveUnknownFields":false}}'You can now install new version of cass-operator as instructed previously.
If you have Prometheus installed in your cluster, you can apply the following command to install the Prometheus support:
kubectl apply -k github.com/k8ssandra/cass-operator/config/prometheusWe have tested the cass-operator to work with cert-manager versions 1.3.1 and 1.5.3. Other versions might work also. To install 1.5.3 to your cluster, run the following command:
kubectl apply -f https://github.com/jetstack/cert-manager/releases/download/v1.5.3/cert-manager.yamlIf you wish to modify the deployment, create your own kustomization.yaml and modify it to your needs. The starting point could be the deployments/config/default and we'll add a cluster scoped installation as our component:
apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: cass-operator
resources:
- github.com/k8ssandra/cass-operator/config/deployments/default?ref=v1.8.0
components:
- github.com/k8ssandra/cass-operator/config/components/cluster
images:
- name: k8ssandra/cass-operator
newTag: v1.8.0We provide both components to modify the installation as well as some additional resources for custom features. At the moment, you can modify the behavior of the installation in the following ways, or remove a component to
ignore the feature (components enabled in the default installation are marked with asterisk). Apply github.com/k8ssandra/cass-operator/config/components/ before component name if using remote installation:
| Component name | Description |
|---|---|
| namespace | Create namespace before installation* |
| webhook | Enable validation webhooks in cass-operator (requires cert-manager) * |
| clusterscope | Install cass-operator in a cluster scope, monitoring all the namespaces |
| auth-proxy | Protect Prometheus /metrics endpoint with api-server authentication |
And following resource. Apply github.com/k8ssandra/cass-operator/config/ before resource name if using remote installation:
| Resource | Description |
|---|---|
| prometheus | Add metrics scraping for Prometheus |
You can find more resources on how Kustomize works from their documentation. You can install kustomize with make kustomize if you do not have it already (this will install it to bin/kustomize).
If the default StorageClass is not suitable for use (volumeBindingMode WaitForFirstConsumer is required) or you wish to use different one, you will need to create an appropriate storage class which will define the type of storage to use for Cassandra nodes in a cluster. For example, here is a storage class for using SSDs in GKE:
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
name: server-storage
provisioner: kubernetes.io/gce-pd
parameters:
type: pd-ssd
replication-type: none
volumeBindingMode: WaitForFirstConsumer
reclaimPolicy: DeletePaste the above to a file and apply:
kubectl apply -f https://raw.githubusercontent.com/k8ssandra/cass-operator/v1.8.0/operator/k8s-flavors/gke/storage.yaml
The following resource defines a Cassandra 3.11.11 datacenter with 3 nodes on one rack, which you can also find at config/samples/cassandra-3.11.x/example-cassdc-minimal.yaml:
apiVersion: cassandra.datastax.com/v1beta1
kind: CassandraDatacenter
metadata:
name: dc1
spec:
clusterName: cluster1
serverType: cassandra
serverVersion: 3.11.11
managementApiAuth:
insecure: {}
size: 3
storageConfig:
cassandraDataVolumeClaimSpec:
storageClassName: server-storage
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
config:
cassandra-yaml:
authenticator: org.apache.cassandra.auth.PasswordAuthenticator
authorizer: org.apache.cassandra.auth.CassandraAuthorizer
role_manager: org.apache.cassandra.auth.CassandraRoleManager
jvm-options:
initial_heap_size: 800M
max_heap_size: 800MApply the above as follows:
kubectl -n cass-operator apply -f https://raw.githubusercontent.com/k8ssandra/cass-operator/master/operator/example-cassdc-yaml/cassandra-3.11.x/example-cassdc-minimal.yamlYou can check the status of pods in the Cassandra cluster as follows:
$ kubectl -n cass-operator get pods --selector cassandra.datastax.com/cluster=cluster1
NAME READY STATUS RESTARTS AGE
cluster1-dc1-default-sts-0 2/2 Running 0 26h
cluster1-dc1-default-sts-1 2/2 Running 0 26h
cluster1-dc1-default-sts-2 2/2 Running 0 26hYou can check to see the current progress of bringing the Cassandra datacenter online by checking the cassandraOperatorProgress field of the CassandraDatacenter's status sub-resource as follows:
$ kubectl -n cass-operator get cassdc/dc1 -o "jsonpath={.status.cassandraOperatorProgress}"
Ready(cassdc and cassdcs are supported short forms of CassandraDatacenter.)
A value of "Ready", as above, means the operator has finished setting up the Cassandra datacenter.
You can also check the Cassandra cluster status using nodetool by invoking it on one of the pods in the Cluster as follows:
$ kubectl -n cass-operator exec -it -c cassandra cluster1-dc1-default-sts-0 -- nodetool status
Datacenter: dc1
===============
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving/Stopped
-- Address Load Tokens Owns (effective) Host ID Rack
UN 10.233.105.125 224.82 KiB 1 65.4% 5e29b4c9-aa69-4d53-97f9-a3e26115e625 r1
UN 10.233.92.96 186.48 KiB 1 61.6% b119eae5-2ff4-4b06-b20b-c492474e59a6 r1
UN 10.233.90.54 205.1 KiB 1 73.1% 0a96e814-dcf6-48b9-a2ca-663686c8a495 r1The operator creates a secure Cassandra cluster by default, with a new superuser (not the traditional cassandra user) and a random password. You can get those out of a Kubernetes secret and use them to log into your Cassandra cluster for the first time. For example:
$ # get CASS_USER and CASS_PASS variables into the current shell
$ CASS_USER=$(kubectl -n cass-operator get secret cluster1-superuser -o json | jq -r '.data.username' | base64 --decode)
$ CASS_PASS=$(kubectl -n cass-operator get secret cluster1-superuser -o json | jq -r '.data.password' | base64 --decode)
$ kubectl -n cass-operator exec -ti cluster1-dc1-default-sts-0 -c cassandra -- sh -c "cqlsh -u '$CASS_USER' -p '$CASS_PASS'"
Connected to cluster1 at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.11.6 | CQL spec 3.4.4 | Native protocol v4]
Use HELP for help.
cluster1-superuser@cqlsh> select * from system.peers;
peer | data_center | host_id | preferred_ip | rack | release_version | rpc_address | schema_version | tokens
-----------+-------------+--------------------------------------+--------------+---------+-----------------+-------------+--------------------------------------+--------------------------
10.28.0.4 | dc1 | 4bf5e110-6c19-440e-9d97-c013948f007c | null | default | 3.11.6 | 10.28.0.4 | e84b6a60-24cf-30ca-9b58-452d92911703 | {'-7957039572378599263'}
10.28.5.5 | dc1 | 3e84b0f1-9c1e-4deb-b6f8-043731eaead4 | null | default | 3.11.6 | 10.28.5.5 | e84b6a60-24cf-30ca-9b58-452d92911703 | {'-3984092431318102676'}
(2 rows)To install a cluster with optional integrated backup/restore and repair utilities, check the k8ssandra/k8ssandra helm charts project.
If you wish to install only the cass-operator, you can run the following command:
helm repo add k8ssandra https://helm.k8ssandra.io/stable
helm install cass-operator k8ssandra/cass-operator -n cass-operator --create-namespace
- Proper token ring initialization, with only one node bootstrapping at a time
- Seed node management - one per rack, or three per datacenter, whichever is more
- Server configuration integrated into the CassandraDatacenter CRD
- Rolling reboot nodes by changing the CRD
- Store data in a rack-safe way - one replica per cloud AZ
- Scale up racks evenly with new nodes
- Scale down racks evenly by decommissioning existing nodes
- Replace dead/unrecoverable nodes
- Multi DC clusters (limited to one Kubernetes namespace)
All features are documented in the User Documentation.
The operator is comprised of the following container images working in concert:
- The operator, built from sources using the kubebuilder v3 structure, from controllers directory.
- The config builder init container, built from sources in datastax/cass-config-builder.
- server-system-logger, a tiny tail logger for outputting Cassandra logs for kubectl. Implemented in logger.Dockerfile
- Cassandra, built from datastax/management-api-for-apache-cassandra, with Cassandra 3.11.11 and 4.0.1 support
- ... or DSE, built from datastax/docker-images.
The Cassandra container must be built with support for management-api, otherwise cass-operator will fail to work correctly.
If the CassandraDatacenter specifies a podTemplateSpec field, then containers with specific names can be used to override default settings in containers that will be created by cass-operator.
Currently cass-operator will create an init container with the name of "server-config-init". Containers that will be created have the names "cassandra" and "server-system-logger".
In general, the values specified in this way by the user will override anything generated by cass-operator.
Of special note is that user-specified environment variables, ports, and volumes in the corresponding containers will be added to the values that cass-operator automatically generates for those containers.
apiVersion: cassandra.datastax.com/v1beta1
kind: CassandraDatacenter
metadata:
name: dc1
spec:
clusterName: cluster1
serverType: cassandra
serverVersion: 3.11.11
managementApiAuth:
insecure: {}
size: 3
podTemplateSpec:
spec:
initContainers:
- name: "server-config-init"
env:
- name: "EXTRA_PARAM"
value: "123"
containers:
- name: "cassandra"
terminationMessagePath: "/dev/other-termination-log"
terminationMessagePolicy: "File"
storageConfig:
cassandraDataVolumeClaimSpec:
storageClassName: server-storage
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 5Gi
config:
cassandra-yaml:
authenticator: org.apache.cassandra.auth.PasswordAuthenticator
authorizer: org.apache.cassandra.auth.CassandraAuthorizer
role_manager: org.apache.cassandra.auth.CassandraRoleManager
jvm-options:
initial_heap_size: 800M
max_heap_size: 800M- Kubernetes cluster, 1.17 or newer.
If you wish to file a bug, enhancement proposal or have other questions, use the issues in this repository or in the k8ssandra/k8ssandra repository. PRs should target this repository and you can link the PR to issue repository with k8ssandra/k8ssandra#ticketNumber syntax.
For other means of contacting, check k8ssandra community resources.
Almost every build, test, or development task requires the following pre-requisites...
- Golang 1.15 or newer
- Docker, either the docker.io packages on Ubuntu, Docker Desktop for Mac, or your preferred docker distribution. Other container engines such as podman should work also.
The operator uses Makefiles for its build process.
This build task will create the operator container image, building or rebuilding the binary from golang sources if necessary:
make docker-buildIf you wish to perform ONLY to the golang build or rebuild, without creating a container image:
make buildOr just make.
To simplify testing processes, the following command will build the docker image and load it to the kind instance.
make docker-kindTests are separated to unit-tests (including envtests) and end-to-end tests. To run the unit tests and envtests, use:
make testtest target will spawn a envtest environment, which will require the ports to be available.
Run fully automated end-to-end tests (these will take a while and require a Kubernetes cluster access with up to 6 worker nodes):
make integ-testTo run a single e2e test:
M_INTEG_DIR=test_dir make integ-testMore details of end-to-end testing are here.
This will destroy all of your data!
Delete your CassandraDatacenters first, otherwise Kubernetes will block deletion of the namespace because we use a finalizer. The following command deletes all CassandraDatacenters from all namespaces:
kubectl delete cassdcs --all-namespaces --all
If you used the make deploy to deploy the operator, replace it with make undeploy to uninstall.
For questions, please reach out on k8ssandra Community channels. For development questions, we are active on our Discord channel #k8ssandra-dev. Or you can open an issue.
Copyright DataStax, Inc.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
For information on the packaged dependencies of Cass Operator and their licenses, check out our open source report.