Add the readme

code-samples/eventing/bookstore-sample-app/db/README.md

@@ -1,11 +1,18 @@
-# Bookstore Database
+# Database Service for Bookstore
+In order to run the Bookstore sample application, you need to create a database and populate it with sample data. This document provides the schema and sample data for the database.
 
-1. Database Schema
-2. Sample Data
+In this tutorial, we will create a PostgreSQL database and populate it with sample data. We will then create **a k8s deployment** that connects to the PostgreSQL database.
 
-## 1. Database Schema
+We will be discussing when we should use Knative Service and what benefit it can bring to us.
+## What Knative features will we learn about?
+- Knative Service
 
-### BookReviews Table
+## What does the final deliverable look like?
+A k8s deployment file that creates a Knative Service that connects to a PostgreSQL database contains the sample data we specified in the SQL file.
+
+## Overview
+
+### The Database Schema
 The BookReviews table contains all reviews made on the bookstore website. 
 
 See the columns of the BookReviews table below:
@@ -14,13 +21,84 @@ See the columns of the BookReviews table below:
 * content (text) - The contents of the comment
 * sentiment (text) - The sentiment results (currently, the values it could take on are 'positive' or 'neutral' or 'negative')
 
-## 2. Sample Data
 
-### BookReviews Table
+### The Sample Data
 The sample rows inserted for the BookReviews table are shown below:
 | id | post_time           | content                      | sentiment |
 |----|---------------------|------------------------------|-----------|
 | 1  | 2020-01-01 00:00:00 | This book is great!          | positive  |
 | 2  | 2020-01-02 00:02:00 | This book is terrible!       | negative  |
 | 3  | 2020-01-03 00:01:30 | This book is okay.           | neutral   |
-| 4  | 2020-01-04 00:00:00 | Meh                          | neutral   |
+| 4  | 2020-01-04 00:00:00 | Meh                          | neutral   |
+
+
+
+
+
+## Implementation
+### Step 1: Create a ConfigMap for SQL Configuration
+
+Use the following command to create a ConfigMap named `sql-configmap` from your `sample.sql` file. This ConfigMap will be used to store your SQL script.
+
+```bash
+kubectl create configmap sql-configmap --from-file=sample.sql
+```
+
+### Step 2: Set Up Persistent Storage
+
+Persistent Volume Claims (PVCs) provide a way to request storage for your database that persists beyond the lifecycle of a pod. Apply your PVC configuration to ensure your PostgreSQL database has the necessary storage.
+
+```bash
+kubectl apply -f PVC.yaml
+```
+
+### Step 3: Deploy the PostgreSQL Server
+
+Deploy your PostgreSQL server as a pod within your Kubernetes cluster. This deployment will utilize the PVC created in the previous step for storage.
+
+```bash
+kubectl apply -f deployment.yaml
+```
+
+### Step 4: Expose PostgreSQL Service
+
+Expose your PostgreSQL server within the Kubernetes cluster to allow connections to the database.
+
+```bash
+kubectl apply -f service.yaml
+```
+
+### Step 5: Initialize the Database
+
+Execute the SQL commands from your `sample.sql` file by running a Kubernetes job. This job ensures your database schema and initial data are set up according to your specifications.
+
+```bash
+kubectl apply -f job.yaml
+```
+
+### Step 6: Interact with Your Database
+
+After setting up your database, you may want to interact with it to run queries or manage data.
+
+1. Retrieve the name of your PostgreSQL deployment pod:
+
+```bash
+kubectl get pods -l app=postgresql
+```
+
+2. Enter the pod’s shell:
+
+```bash
+kubectl exec -it <deployment pod name> -- /bin/bash
+```
+
+3. Connect to your PostgreSQL database:
+
+```bash
+psql -h postgresql -U myuser -d mydatabase
+```
+Use `mypassword` when prompted for the password.
+
+## Conclusion
+
+By following this guide, you have successfully deployed a PostgreSQL server on a Kubernetes cluster, set up persistent storage, and initialized your database using a Kubernetes job. Congratulations! Your bookstore now has the database service.