Memcached Operator

Overview

The Memcached Operator is a Kubernetes operator designed to automate the deployment and management of Memcached instances within a Kubernetes cluster. It leverages a custom resource definition (CRD) to manage the lifecycle of Memcached deployments.

Here is the architecture of the operator:

Data flow diagram of a kubernetes memcache operator with nettools

Features

• Automated Deployment: Simplifies the deployment of Memcached instances.
• Scalability: Supports scaling of Memcached deployments.
• Status Monitoring: Provides updates on the status of Memcached custom resources.
• Debugging Support: Each pod includes a debugging container (nettools) for network troubleshooting and diagnostics. It use (nicolaka/netshoot) image for nettools installation.

Custom Resource Definition (CRD)

The operator utilizes a CRD named MemcachedDeployment. Below is an example configuration:

apiVersion: cache.example.com/v1
kind: MemcachedDeployment
metadata:
  name: example-memcached
spec:
  size: 3
  image: memcached:1.4.36-alpine

The CRD is defined as follows:

apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
  name: memcacheddeployments.cache.example.com
spec:
  group: cache.example.com
  versions:
    - name: v1
      served: true
      storage: true
      schema:
        openAPIV3Schema:
          type: object
          properties:
            spec:
              type: object
              properties:
                size:
                  type: integer
                  description: "Specifies the number of Memcached instances."
                image:
                  type: string
                  description: "Defines the Docker image to use for the deployment."
  scope: Namespaced
  names:
    plural: memcacheddeployments
    singular: memcacheddeployment
    kind: MemcachedDeployment
    shortNames:
      - mcd

Fields:

• size: Specifies the number of Memcached instances.
• image: Defines the Docker image to use for the deployment.

Prerequisites

• Kubernetes cluster (v1.11.3 or higher)
• kubectl (v1.11.3 or higher)
• Go (v1.22.0 or higher)
• Docker (v17.03 or higher)

Installation

1. Clone the repository:

   git clone https://github.com/sagoresarker/memcached-operator.git
   cd memcached-operator

2. Build and push the operator image:

   make docker-build docker-push IMG=<your-registry>/memcached-operator:tag

3. Install the CRDs:

   make install

4. Deploy the operator:

   make deploy IMG=<your-registry>/memcached-operator:tag

Usage

1. To create a Memcached deployment, use the following YAML configuration:

   apiVersion: cache.example.com/v1
   kind: MemcachedDeployment
   metadata:
     name: example-memcached
   spec:
     size: 3
     image: memcached:1.4.36-alpine

2. Apply the custom resource:

   kubectl apply -f config/samples/cache_v1_memcacheddeployment.yaml

3. Verify the deployment:

   kubectl get memcacheddeployment
   kubectl get pods

Development

• Local Development:

  make run

• Running Tests:

  make test

Project Distribution

To build an installer for distribution:

make build-installer IMG=<your-registry>/memcached-operator:tag

This generates an install.yaml file in the dist directory, which can be used to install the operator:

kubectl apply -f https://raw.githubusercontent.com/<org>/memcached-operator/<tag or branch>/dist/install.yaml

Cleanup

To remove the operator and CRDs from your cluster:

make uninstall
make undeploy