cdk8s-mongo-sts

Create a Replicated, Password protected MongoDB Statefulset on Kubernetes, powered by the cdk8s project 🚀

Disclaimer

This construct is under heavy development, and breaking changes will be introduced very often. Please don't forget to version lock your code if you are using this construct.

Overview

cdk8s-mongo-sts is a cdk8s library, and also uses cvallance/mongo-k8s-sidecar to manage the MongoDB replicaset.

import { Construct } from 'constructs';
import { App, Chart, ChartProps } from 'cdk8s';
import { MyMongo } from 'cdk8s-mongo-sts';

export class MyChart extends Chart {
  constructor(scope: Construct, id: string, props: ChartProps = { }) {
    super(scope, id, props);
        new MyMongo(this, 'dev', {
            image: 'mongo',
            namespace: 'databases',
            defaultReplicas: 3,
            volumeSize: '10Gi',
            createStorageClass: true,
            volumeProvisioner: 'kubernetes.io/aws-ebs',
            storageClassName: "io1-slow",
            storageClassParams: {
              type: 'io1',
              fsType: 'ext4',
              iopsPerGB: "10",
            },
            nodeSelectorParams: {
              database: "dev",
            },
        });
    }
}

const app = new App();
new MyChart(app, 'asd');
app.synth();

Create a secret for your DB that starts with the same name as your Statefulset with the following keys :

username
password

See this for documentation on Kubernetes secrets.

Then the Kubernetes manifests created by cdk8s synth command will have Kubernetes resources such as Statefulset, Service, ClusterRole, ClusterRoleBinding, ServiceAccount, and StorageClass as follows.

manifest.k8s.yaml

allowVolumeExpansion: true
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: io1-slow
parameters:
  fsType: ext4
  type: io1
  iopsPerGB: "10"
provisioner: kubernetes.io/aws-ebs
reclaimPolicy: Retain
---
apiVersion: v1
kind: Service
metadata:
  name: dev
  namespace: databases
spec:
  clusterIP: None
  ports:
    - port: 27017
      targetPort: 27017
  selector:
    db: dev
  type: ClusterIP
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: get-pods-role
  namespace: databases
rules:
  - apiGroups:
      - "*"
    resources:
      - pods
    verbs:
      - list
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: dev
  namespace: databases
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: dev
  namespace: databases
roleRef:
  apiGroup: ""
  kind: ClusterRole
  name: get-pods-role
subjects:
  - kind: ServiceAccount
    name: dev
    namespace: databases
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: dev
  namespace: databases
spec:
  replicas: 3
  selector:
    matchLabels:
      db: dev
  serviceName: dev
  template:
    metadata:
      labels:
        db: dev
    spec:
      containers:
        - env:
            - name: MONGO_SIDECAR_POD_LABELS
              value: db=dev
            - name: KUBE_NAMESPACE
              value: databases
            - name: MONGODB_DATABASE
              value: admin
            - name: MONGODB_USERNAME
              valueFrom:
                secretKeyRef:
                  key: username
                  name: dev
            - name: MONGODB_PASSWORD
              valueFrom:
                secretKeyRef:
                  key: password
                  name: dev
          image: cvallance/mongo-k8s-sidecar
          name: mongo-sidecar
        - args:
            - --replSet
            - rs0
            - --bind_ip
            - 0.0.0.0
            - --dbpath
            - /data/db
            - --oplogSize
            - "128"
          env:
            - name: MONGO_INITDB_ROOT_USERNAME
              valueFrom:
                secretKeyRef:
                  key: username
                  name: dev
            - name: MONGO_INITDB_ROOT_PASSWORD
              valueFrom:
                secretKeyRef:
                  key: password
                  name: dev
          image: mongo
          name: dev
          ports:
            - containerPort: 27017
          resources:
            limits:
              cpu: 400m
              memory: 512Mi
            requests:
              cpu: 200m
              memory: 256Mi
          volumeMounts:
            - mountPath: /data/db
              name: dev
      nodeSelector:
        database: dev
      securityContext:
        fsGroup: 999
        runAsGroup: 999
        runAsUser: 999
      serviceAccountName: dev
      terminationGracePeriodSeconds: 10
  volumeClaimTemplates:
    - metadata:
        name: dev
      spec:
        accessModes:
          - ReadWriteOnce
        resources:
          requests:
            storage: 10Gi
        storageClassName: io1-slow

Installation

TypeScript

Use npm or yarn to install.

$ npm install -s cdk8s-mongo-sts

or

$ yarn add cdk8s-mongo-sts

Python

$ pip install cdk8s-mongo-sts

Contribution

1. Fork (https://github.com/Hunter-Thompson/cdk8s-mongo-sts/fork)

2. Bootstrap the repo:

   npx projen   # generates package.json 
   yarn install # installs dependencies

3. Development scripts:

   Command	Description
   yarn compile	Compiles typescript => javascript
   yarn watch	Watch & compile
   yarn test	Run unit test & linter through jest
   yarn test -u	Update jest snapshots
   yarn run package	Creates a dist with packages for all languages.
   yarn build	Compile + test + package
   yarn bump	Bump version (with changelog) based on [conventional commits]
   yarn release	Bump + push to master

4. Create a feature branch

5. Commit your changes

6. Rebase your local changes against the master branch

7. Create a new Pull Request (use conventional commits for the title please)

Licence

Apache License, Version 2.0

Author

Hunter-Thompson