https://example.com/tags/nodejs/ Recent content in Nodejs on Iulian Mocanu Hugo -- gohugo.io en Mon, 20 May 2024 00:00:00 +0000 https://example.com/post/k8s-nodejs-fullstack/ Mon, 20 May 2024 00:00:00 +0000 https://example.com/post/k8s-nodejs-fullstack/ <h2 id="description-of-kubernetes-resources">Description of Kubernetes Resources</h2> <h3 id="database">Database</h3> <ul> <li><strong>Deployment (<code>database</code>)</strong>: Deploys PostgreSQL (<code>postgres:14</code> image) database with initialization from <code>init.sql</code> using a <code>ConfigMap</code>. It mounts <code>database-volume-claim</code> for persistent storage of PostgreSQL data.</li> <li><strong>Service (<code>database-service</code>)</strong>: Provides a stable endpoint (<code>database.development.svc.cluster.local</code>) for accessing the PostgresSQL database (<code>postgres</code> Deployment) internally within the Kubernetes cluster.</li> <li><strong>ConfigMap (<code>database-init</code>)</strong>: Contains <code>init.sql</code> script that initializes the database schema (<code>users</code> table) upon PostgreSQL container startup.</li> <li><strong>Secret (<code>database-secret</code>)</strong>: Stores sensitive information such as PostgreSQL credentials (<code>POSTGRES_USER</code>, <code>POSTGRES_PASSWORD</code>, <code>POSTGRES_DB</code>) encoded in base64.</li> <li><strong>PersistentVolume</strong>: Provides storage for PostgreSQL data.​</li> <li><strong>PersistentVolumeClaim (<code>database-volume-claim</code>)</strong>: Requests persistent storage for storing PostgreSQL data (<code>/var/lib/postgresql/data</code>).</li> </ul> <h3 id="backend">Backend</h3> <ul> <li><strong>Deployment (<code>backend</code>)</strong>: Manages the backend application (<code>backend:dev</code> image) responsible for serving requests from the web browser and interacting with the database. It pulls PostgreSQL credentials from <code>database-secret</code> for database connectivity.</li> <li><strong>Service (<code>backend-service</code>)</strong>: Provides a stable endpoint (<code>backend.development.svc.cluster.local</code>) for accessing the backend application (<code>backend</code> Deployment) internally within the Kubernetes cluster.</li> <li><strong>ConfigMap (<code>backend-config</code>)</strong>: Contains the value of database service endpoint <code>database.development.svc.cluster.local</code>.</li> </ul> <h3 id="frontend">Frontend</h3> <ul> <li><strong>Deployment (<code>frontend</code>)</strong>: Manages the frontend application (using the <code>frontend:dev</code> image) which is responsible for serving requests from the web browser and interacting with the backend application. The frontend retrieves the URL of the backend API from a ConfigMap named <code>frontend-config</code>.</li> <li><strong>Service (<code>frontend-service</code>)</strong>: Provides a stable endpoint (<code>frontend.development.svc.cluster.local</code>) for accessing the frontend application (<code>frontend</code> Deployment) internally within the Kubernetes cluster.</li> <li><strong>ConfigMap (<code>backend-config</code>)</strong>: Contains the value of backend api url <code>http://backend.development.svc.cluster.local:3000/api/users</code>.</li> </ul> <h2 id="network-flow-description">Network Flow Description</h2> <p>The network flow from the web browser to the database application via the backend application in Kubernetes involves the following steps:</p>