PostgreSQL Installation onAzure Kubernetes Service (AKS)

What is Postgresql

An Introduction to PostgreSQL: Power, Flexibility, and Reliability

PostgreSQL, often referred to as Postgres, is an open-source relational database management system (RDBMS) renowned for its robustness, extensibility, and adherence to SQL standards. Originally developed at the University of California, Berkeley, PostgreSQL has evolved into a powerful database system trusted by organizations worldwide.

History and Development

PostgreSQL traces its roots back to the Ingres project at Berkeley, which began in the 1970s. In the mid-1980s, Michael Stonebraker and his team at Berkeley released an improved version of Ingres, known as Postgres (Post Ingres). This project laid the groundwork for what would eventually become PostgreSQL.

In 1996, the project was officially named PostgreSQL to reflect its support for SQL. Since then, it has undergone continuous development and refinement, with contributions from a global community of developers and organizations. The PostgreSQL Global Development Group oversees its development and releases.

Features and Capabilities

PostgreSQL offers a rich set of features that make it suitable for a wide range of applications, from small-scale projects to large-scale enterprise systems. Some key features include:

1. ACID Compliance: PostgreSQL ensures data integrity by adhering to the principles of Atomicity, Consistency, Isolation, and Durability (ACID).
2. Extensibility: The PostgreSQL extension system allows developers to add custom functionality through extensions written in various programming languages, including C, Python, and SQL.
3. JSON and NoSQL Support: PostgreSQL provides native support for JSON data types and allows for querying and indexing JSON documents, making it a viable choice for applications requiring NoSQL capabilities alongside traditional SQL functionality.
4. Full Text Search: PostgreSQL includes robust full-text search capabilities, enabling efficient searching and indexing of textual data.
5. Geospatial Support: With extensions like PostGIS, PostgreSQL offers advanced geospatial capabilities, allowing storage, indexing, and querying of geographical data.
6. Concurrency Control: PostgreSQL employs sophisticated concurrency control mechanisms, such as Multi-Version Concurrency Control (MVCC), to ensure transactions can be executed concurrently without compromising data consistency.
7. Replication and High Availability: PostgreSQL supports various replication methods, including streaming replication and logical replication, to achieve high availability and data redundancy.

Community and Support

One of PostgreSQL’s strengths is its vibrant and supportive community. The PostgreSQL community encompasses developers, users, and advocates who collaborate through mailing lists, forums, conferences, and code contributions. The community-driven nature of PostgreSQL ensures timely support, frequent updates, and a wealth of resources for users at all levels of expertise.

Use Cases

PostgreSQL is suitable for a diverse array of use cases across industries, including:

• Web Applications: Many web frameworks and content management systems integrate seamlessly with PostgreSQL, making it a popular choice for web development.
• Data Warehousing: PostgreSQL’s analytical capabilities and extensibility make it well-suited for data warehousing and business intelligence applications.
• Geographic Information Systems (GIS): PostGIS extension enables PostgreSQL to store and analyze geospatial data, making it indispensable for GIS applications.
• Enterprise Applications: PostgreSQL’s reliability, scalability, and ACID compliance make it a robust backend for mission-critical enterprise systems.
• Startups and Small Businesses: The open-source nature of PostgreSQL and its low operational costs make it an attractive option for startups and small businesses looking for a reliable database solution.

Conclusion

PostgreSQL stands out as a powerful, flexible, and reliable database system that continues to evolve with the needs of modern applications. Its rich feature set, strong community support, and commitment to standards compliance make it a compelling choice for organizations seeking a robust database solution.

Whether you’re building a small-scale application or managing a large-scale enterprise system, PostgreSQL offers the performance, scalability, and versatility to meet your needs and grow with your business.

Deploy Postgresql on AKS

To avoid getting the following errors, you must first create the nfs storageclass

initdb: error: could not change permissions of directory "/var/lib/postgresql/data": Operation not permitted

FATAL:  could not open file "pg_wal/000000010000000000000001": No such file or directory

could not link file "pg_wal/xlogtemp.38" to "pg_wal/000000010000000000000001": Operation not supported

Create storage Class

kubectl apply -f postgres-sc.yaml

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: azurefile-csi-nfs
provisioner: file.csi.azure.com
allowVolumeExpansion: true
parameters:
  protocol: nfs
mountOptions:
  - nconnect=4
  - noresvport
  - actimeo=30

Create PVC, Deployment, Service and Configmap for Postgresql

apiVersion: v1
kind: ConfigMap
metadata:
  name: postgres-config
  labels:
    app: postgres-bawdb
data:
  POSTGRES_DB: bawdb
  POSTGRES_USER: bawdb
  POSTGRES_PASSWORD: xxxxx
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: postgres-bawdb-pv-volume
  labels:
    app: postgres-bawdb
spec:
  storageClassName: azurefile-csi-nfs
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 30Gi
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: postgres-bawdb
spec:
  replicas: 1
  selector:
    matchLabels:
      app: postgres-bawdb
  template:
    metadata:
      labels:
        app: postgres-bawdb
    spec:
      initContainers:
        - name: init
          image: alpine
          command: ["sh", "-c", "chown -R 999:1000 /var/lib/postgresql/data"]
          volumeMounts:
            - mountPath: /var/lib/postgresql/data
              name: postgredb
      containers:
        - name: postgres-bawdb
          image: postgres:13.10
          imagePullPolicy: "IfNotPresent"
          ports:
            - containerPort: 5432
          envFrom:
            - configMapRef:
                name: postgres-config
          volumeMounts:
            - mountPath: /var/lib/postgresql/data
              name: postgredb
      volumes:
        - name: postgredb
          persistentVolumeClaim:
            claimName: postgres-bawdb-pv-volume


---
apiVersion: v1
kind: Service
metadata:
  name: postgres-bawdb
  labels:
    app: postgres-bawdb
spec:
  type: NodePort
  ports:
   - port: 5432
  selector:
   app: postgres-bawdb