elasticsearch-operator

WORK IN PROGRESS

Elasticsearch operator to run Elasticsearch cluster on top of Openshift and Kubernetes. Operator uses Operator Framework SDK.

Why Use An Operator?

Operator is designed to provide self-service for the Elasticsearch cluster operations. See the diagram on operator maturity model.

Elasticsearch operator ensures proper layout of the pods
Elasticsearch operator enables proper rolling cluster restarts
Elasticsearch operator provides kubectl interface to manage your Elasticsearch cluster
Elasticsearch operator provides kubectl interface to monitor your Elasticsearch cluster

Getting started

Prerequisites

Cluster administrator must set vm.max_map_count sysctl to 262144 on the host level of each node in your cluster prior to running the operator.
In case hostmounted volume is used, the directory on the host must have 777 permissions and the following selinux labels (TODO).
In case secure cluster is used, the certificates must be pre-generated and uploaded to the secret <elasticsearch_cluster_name>-certs

Kubernetes

Make sure certificates are pre-generated and deployed as secret. Upload the Custom Resource Definition to your Kubernetes cluster:

$ kubectl create -f deploy/crd.yaml

Deploy the required roles to the cluster:

$ kubectl create -f deploy/rbac.yaml

Deploy custom resource and the Deployment resource of the operator:

$ kubectl create -f deploy/cr.yaml
$ kubectl create -f deploy/operator.yaml

OpenShift

As a cluster admin apply the template with the roles and permissions:

$ oc process -f deploy/openshift/admin-elasticsearch-template.yaml | oc apply -f -

The template deploys CRD, roles and rolebindings. You can pass variables:

NAMESPACE to specify which namespace's default ServiceAccount will be allowed to manage the Custom Resource.
ELASTICSEARCH_ADMIN_USER to specify which user of OpenShift will be allowed to manage the Custom Resource.

For example:

$ oc process NAMESPACE=myproject ELASTICSEARCH_ADMIN_USER=developer -f deploy/openshift/admin-elasticsearch-template.yaml | oc apply -f -

Grant permissions to extra users by giving them the role elasticsearch-operator.

As the user which was specified as ELASTICSEARCH_ADMIN_USER on previous step:

Make sure the secret with Elasticsearch certificates exists and is named <elasticsearch_cluster_name>-certs

Then process the following template:

$ oc process -f deploy/openshift/elasticsearch-template.yaml | oc apply -f -

The template deploys the Custom Resource and the operator deployment. You can pass the following variables to the template:

NAMESPACE - namespace where the Elasticsearch cluster will be deployed. Must be the same as the one specified by admin
ELASTICSEARCH_CLUSTER_NAME - name of the Elasticsearch cluster to be deployed

For example:

$ oc process NAMESPACE=myproject ELASTICSEARCH_CLUSTER_NAME=elastic1 -f deploy/openshift/elasticsearch-template.yaml | oc apply -f -

Openshift Alternatives - Make targets

If you are using an image built in a different node, you can specify to use a remote registry by setting the environment variable REMOTE_REGISTRY=true before running any of the targets below. See hack/deploy-image.sh and hack/deploy.sh for more details.

REMOTE_REGISTRY Set to true if you are running the cluster on a different machine than the one you are developing on. For example, if you are running a cluster in a local libvirt or minishift environment, you may want to build the image on the host and push them to the cluster running in the VM. You will need a username with a password (i.e. not the default system:admin user). If your cluster was deployed with the allow_all identity provider, you can create a user like this: oc login --username=admin --password=admin, then assign it rights: oc login --username=system:admin oc adm policy add-cluster-role-to-user cluster-admin admin If you used the new openshift-installer, it created a user named kubeadmin with the password in the file installer/auth/kubeadmin_password. oc login --username=kubeadmin --password=$( cat ../installer/auth/kubeadmin_password ) The user should already have cluster-admin rights.

It is additionally possible to deploy the operator to an Openshift cluster using the provided make targets. These targets assume you have cluster admin access. Following are a few of these targets:

deploy

Deploy the resources for the operator, build the operator image, push the image to the Openshift registry

deploy-setup

Deploy the pre-requirements for the operator to function (i.e. CRD, RBAC, sample secret)

deploy-example

Deploy an example custom resource for a single node Elasticsearch cluster

deploy-undeploy

Remove all deployed resources

run

Deploy the example cluster and start running the operator. The end result is that there will be an elasticsearch custom resource, and an elasticsearch pod running. You can view the operator log by looking at the log file specified by $(RUN_LOG) (default elasticsearch-operator.log). The command is run in the background - when finished, kill the process by killing the pid, which is written to the file $(RUN_PID) (default elasticsearch-operator.pid) e.g. kill $(cat elasticsearch-operator.pid)

Customize your cluster

Image customization

The operator is designed to work with quay.io/openshift/origin-logging-elasticsearch6 image. To use a different image, edit manifests/image-references before deployment, or edit the elasticsearch cr after deployment e.g. oc edit elasticsearch elasticsearch.

Storage configuration

Storage is configurable per individual node type. Possible configuration options:

Hostmounted directory
Empty directory
Existing PersistentVolume
New PersistentVolume generated by StorageClass

Elasticsearch cluster topology customization

Decide how many nodes you want to run.

Elasticsearch node configuration customization

TODO

Exposing elasticsearch service with a route

Obtain the CA cert from Elasticsearch.

oc extract secret/elasticsearch --to=. --keys=admin-ca

Create a re-encrypt route.

In the Re-encrypt termination example, use the contents of the file admin-ca for spec.tls.destinationCACertificate. You do not need to set the spec.tls.key, spec.tls.certificate and spec.tls.caCertificate parameters shown in the example.

Supported features

Kubernetes TBD+ and OpenShift TBD+ are supported.

Testing

In a real deployment OpenShift monitoring will be installed. However for testing purposes, you should install the monitoring CRDs:

[REMOTE_REGISTRY=true] make deploy-setup

Use REMOTE_REGISTRY=true make deploy-image to build the image and copy it to the remote registry.

E2E Testing

To run the e2e tests, install the above CRDs and from the repo directory, run:

make test-e2e

This assumes:

the operator-sdk installed (e.g. make operator-sdk)
the operator image is built (e.g. make image) and available to the OKD cluster

Note: It is necessary to set the IMAGE_ELASTICSEARCH_OPERATOR environment variable to a valid pull spec in order to run this test against local changes to the elasticsearch-operator. For example:

make deploy-image && \
IMAGE_ELASTICSEARCH_OPERATOR=quay.io/openshift/origin-elasticsearch-operator:latest make test-e2e

Dev Testing

You should first ensure that you have commands such as imagebuilder and operator-sdk available by using something like https://github.com/openshift/origin-aggregated-logging/blob/master/hack/sdk_setup.sh.

To set up your local environment based on what will be provided by OLM, run:

sudo sysctl -w vm.max_map_count=262144
ELASTICSEARCH_OPERATOR=$GOPATH/src/github.com/openshift/elasticsearch-operator
[REMOTE_REGISTRY=true] make deploy-setup
[REMOTE_REGISTRY=true] make deploy-example

To test on an OKD cluster, you can run:

make run

To remove created API objects:

make undeploy

Building a Universal Base Image (UBI) based image

You must first oc login api.ci.openshift.org. You'll need these credentials in order to pull images from the UBI registry.

The image build process for UBI based images uses a private yum repo. In order to use the private yum repo, you will need access to https://github.com/openshift/release/blob/master/ci-operator/infra/openshift/release-controller/repos/ocp-4.1-default.repo and https://github.com/openshift/shared-secrets/blob/master/mirror/ops-mirror.pem Note that the latter is private and requires special permission to access.

The best approach is to clone these repos under $GOPATH/src/github.com/openshift which the build scripts will pick up automatically. If you do not, the build script will attempt to clone them to a temporary directory.

Running a full integration test with a 4.x cluster

If you have a local clone of origin-aggregated-logging under $GOPATH/github.com/openshift/origin-aggregated-logging you can use its hack/get-cluster-run-tests.sh to build the logging, elasticsearch-operator, and cluster-logging-operator images; deploy a 4.x cluster; push the images to the cluster; deploy logging; and launch the logging CI tests.

Pushing an image to a 4.x cluster

You'll need podman in addition to docker.

If you used the new openshift-installer, it creates a user named kubeadmin with the password in the file installer/auth/kubeadmin_password.

To push the image to the remote registry, set REMOTE_REGISTRY=true, PUSH_USER=kubeadmin, KUBECONFIG=/path/to/installer/auth/kubeconfig, and PUSH_PASSWORD=$( cat /path/to/installer/auth/kubeadmin_password ). You do not have to oc login to the cluster. If you already built the image, use SKIP_BUILD=true to do a push only.

REMOTE_REGISTRY=true PUSH_USER=kubeadmin SKIP_BUILD=true \
KUBECONFIG=/path/to/installer/auth/kubeconfig \
PUSH_PASSWORD=$( cat /path/to/installer/auth/kubeadmin_password ) \
make deploy-image

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