couchbase

Couchbase

Couchbase is an open-source, distributed multi-model NoSQL document-oriented database software package that is optimized for interactive applications. Couchbase Server is designed to provide easy-to-scale key-value or JSON document access with low latency and high sustained throughput. It is designed to be clustered from a single machine to very large-scale deployments spanning many machines.

Prerequisites

• Kubernetes 1.20+
• PV support on the underlying infrastructure
• Kanister controller version 0.22.0 installed in your cluster
• Kanctl CLI installed (https://docs.kanister.io/tooling.html#kanctl)
• Couchbase application needs at least 4G of memory and 4 cpus to run. Make sure that your cluster nodes has required resources.
• Docker CLI installed

Build and push couchbase-tools docker image

Kanister actions are specified in the Blueprint CR. The example Blueprint for the Couchbase application uses the couchbase-tools docker image to perform required actions. Follow the steps below to build the docker image with all the necessary tools.

# Clone Kanister Github repo locally
$ git clone https://github.com/kanisterio/kanister.git <path_to_kanister>

# Build couchbase-tools docker image
$ docker build -t <registry>/<repository>/couchbase-tools:<tag_name> <path_to_kanister>/docker/couchbase-tools/
$ docker push <registry>/<repository>/couchbase-tools:<tag_name>

Replace <registry>, <repository> and <tag_name> placeholders with actual values in couchbase-blueprint.yaml.

Chart Details

We will be using couchbase official helm charts to deploy Couchbase Operator and Couchbase cluster on Kubernetes cluster using the Helm package manager.

Installing the Chart

To install the chart with the release name cb-example:

#NOTE: The latest couchbase helm charts require Helm 3.1+
$ helm repo add couchbase https://couchbase-partners.github.io/helm-charts
$ helm repo update
# Create couchbase-test namespace
$ kubectl create ns couchbase-test
# The below chart installs couchbase cluster, admission controller and operator
$ helm install cb-example couchbase/couchbase-operator --namespace couchbase-test \
    --set cluster.servers.default.size=2 \
    --set cluster.servers.default.services[0]=data \
    --set cluster.servers.default.services[1]=query \
    --set cluster.servers.default.services[2]=index

NOTE:

Kanister operator roles needs to be updated in order to access custom resource. For testing purpose, we can give cluster-admin role to kanister-operator service account with -

kubectl create -f kanister-clusteradmin-binding.yaml

Integrating with Kanister

If you have deployed couchbase operator with other name than cb-example and namespace other than couchbase-test, you need to modify the commands used below to use the correct name and namespace

Create Profile

Create Profile CR if not created already

$ kanctl create profile s3compliant --access-key <aws-access-key-id> \
	--secret-key <aws-secret-key> \
	--bucket <s3-bucket-name> --region <region-name> \
	--namespace couchbase-test

NOTE:

The command will configure a location where artifacts resulting from Kanister data operations such as backup should go. This is stored as a profiles.cr.kanister.io CustomResource (CR) which is then referenced in Kanister ActionSets. Every ActionSet requires a Profile reference to complete the action. This CR (profiles.cr.kanister.io) can be shared between Kanister-enabled application instances.

Create Blueprint

NOTE: v2 Blueprints are experimental and are not supported with standalone Kanister.

Create Blueprint in the same namespace as the controller

$ kubectl create -f couchbase-blueprint.yaml -n kasten-io
blueprint.cr.kanister.io/couchbase-blueprint created

Once Couchbase is running, you can populate it with some data. Let's add some documents to the default bucket:

# Connect to couchbase cluster pod
$ kubectl exec -ti cb-example-couchbase-cluster-0000 -n couchbase-test -- bash

# From inside the shell, use the cbc command to insert some data into the default bucket
# Replace <password> with the correct password.
$ cbc-create -u Administrator -P <password>  doc1 -V '{"name":"vivek", "age": 25}'
$ cbc-create -u Administrator -P <password>  doc2 -V '{"name":"prasad", "age": 25}'

# verify data
$ cbc-n1ql -u Administrator -P <password> 'create primary index on default'
$ cbc-n1ql -u Administrator -P <password> 'select * from default'
---> Encoded query: {"statement":"select * from default"}

{"default":{"name":"prasad", "age": 25}},
{"default":{"name":"vivek", "age": 25}},
---> Query response finished
{
"requestID": "46178b60-8297-43f3-a94e-19a6f9207f98",
"signature": {"*":"*"},
"results": [
],
"status": "success",
"metrics": {"elapsedTime": "14.711966ms","executionTime": "14.510259ms","resultCount": 1,"resultSize": 40}
}

Protect the Application

You can now take a backup of the Couchbase cluster data using an ActionSet defining backup for this application. Create an ActionSet in the same namespace as the controller.

$ kubectl get profile -n couchbase-test
NAME               AGE
s3-profile-bghqw   2m42s

$ kanctl create actionset --action backup --namespace kasten-io --blueprint couchbase-blueprint --profile couchbase-test/s3-profile-bghqw --objects couchbase.com/v2/couchbaseclusters/couchbase-test/cb-example-couchbase-cluster
actionset backup-g648n created

$ kubectl --namespace kasten-io get actionsets.cr.kanister.io
NAME           AGE
backup-g648n   37s

# View the status of the actionset
$ kubectl --namespace kasten-io describe actionset backup-g648n

Disaster strikes!

Let's say someone with accidentally deleted the bucket using the following command in couchbase cluster pod:

# Drop default bucket
# Replace <password> with the correct password.
$ cbc-bucket-delete -u Administrator -P <password> default
Requesting /pools/default/buckets/default
200
  Cache-Control: no-cache,no-store,must-revalidate
  Content-Length: 0
  Date: Thu, 12 Dec 2019 12:01:06 GMT
  Expires: Thu, 01 Jan 1970 00:00:00 GMT
  Pragma: no-cache
  Server: Couchbase Server
  X-Content-Type-Options: nosniff
  X-Frame-Options: DENY
  X-Permitted-Cross-Domain-Policies: none
  X-XSS-Protection: 1; mode=block

Restore the Application

To restore the missing data, you should use the backup that you created before. An easy way to do this is to leverage kanctl, a command-line tool that helps create ActionSets that depend on other ActionSets:

$ kanctl --namespace kasten-io create actionset --action restore --from "backup-g648n"
actionset restore-backup-g648n-64gqm created

# View the status of the ActionSet
kubectl --namespace kasten-io describe actionset restore-backup-g648n-64gqm

You should now see that the data has been successfully restored to Couchbase cluster!

# Recreate index
# Replace <password> with the correct password.
$ cbc-n1ql -u Administrator -P <password> 'drop primary index on default'
$ cbc-n1ql -u Administrator -P <password> 'create primary index on default'
$ cbc-n1ql -u Administrator -P <password> 'select * from default'
---> Encoded query: {"statement":"select * from default"}

{"default":{"name":"vivek", "age": 25}},
{"default":{"name":"prasad", "age": 25}},
---> Query response finished
{
"requestID": "8325812b-5c7b-4848-a59e-82d08ba11191",
"signature": {"*":"*"},
"results": [
],
"status": "success",
"metrics": {"elapsedTime": "18.153378ms","executionTime": "17.972551ms","resultCount": 2,"resultSize": 79}
}

Delete the Artifacts

The artifacts created by the backup action can be cleaned up using the following command:

$ kanctl --namespace kasten-io create actionset --action delete --from "backup-g648n" --namespacetargets kasten-io
actionset "delete-backup-g648n-k9ncm" created

# View the status of the ActionSet
$ kubectl --namespace kasten-io describe actionset delete-backup-g648n-k9ncm

Troubleshooting

If you run into any issues with the above commands, you can check the logs of the controller using:

$ kubectl --namespace kasten-io logs -l app=kanister-operator

you can also check events of the actionset

$ kubectl describe actionset restore-backup-g648n-64gqm -n kasten-io

Uninstalling the Chart

Use helm delete command to remove couchbase-operator and couchbase-cluster

$ helm delete cb-example -n couchbase-test
$ helm delete couchbase-operator -n couchbase-test

The command removes all the Kubernetes components associated with the chart and deletes the release.

Delete Blueprint and Profile CR

$ kubectl delete blueprints.cr.kanister.io couchbase-blueprint -n kasten-io

$ kubectl get profiles.cr.kanister.io -n couchbase-test
NAME               AGE
s3-profile-sph7s   2h

$ kubectl delete profiles.cr.kanister.io s3-profile-sph7s -n couchbase-test