Sample App: Database Migration

code-samples/eventing/bookstore-sample-app/db/PVC.yaml

@@ -0,0 +1,10 @@
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: postgres-pvc
+spec:
+  accessModes:
+    - ReadWriteOnce
+  resources:
+    requests:
+      storage: 1Gi

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

@@ -2,6 +2,7 @@
 
 1. Database Schema
 2. Sample Data
+3. Deployment on K8s Cluster
 
 ## 1. Database Schema
 
@@ -23,4 +24,30 @@ The sample rows inserted for the BookReviews table are shown below:
 | 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   |
+
+## 3. Deployment on K8s Cluster
+1. Set up a Kubernetes Cluster
+i. [minikube start](https://minikube.sigs.k8s.io/docs/start/)
+ii. [kind quickstart](https://kind.sigs.k8s.io/docs/user/quick-start/)
+
+2. Set up the configmap to link the sample.sql file
+`kubectl create configmap sql-configmap --from-file=sample.sql`
+
+3. Stand up the Persistent Volume Claim for Postgres server
+`kubectl apply -f PVC.yaml`
+
+4. Create the deployment pod for the Postgres server
+`kubectl apply -f deployment.yaml`
+
+5. Expose the port for the Postgres server
+`kubectl apply -f service.yaml`
+
+6. Run the job for executing the queries from sample.sql
+`kubectl apply -f job.yaml`
+
+7. To interact with the database
+i. Get the deployment pod name: `kubectl get pods -l app=postgresql`
+ii. `kubectl exec -it (deployment pod name) -- /bin/bash`
+iii. `psql -h postgresql -U myuser -d mydatabase`
+iv. Use `mypassword` when prompted for the password

code-samples/eventing/bookstore-sample-app/db/deployment.yaml

@@ -0,0 +1,33 @@
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: postgresql
+spec:
+  replicas: 1
+  selector:
+    matchLabels:
+      app: postgresql
+  template:
+    metadata:
+      labels:
+        app: postgresql
+    spec:
+      containers:
+        - name: postgresql
+          image: quay.io/enterprisedb/postgresql
+          env:
+            - name: POSTGRES_DB
+              value: mydatabase
+            - name: POSTGRES_USER
+              value: myuser
+            - name: POSTGRES_PASSWORD
+              value: mypassword
+          ports:
+            - containerPort: 5432
+          volumeMounts:
+            - name: postgres-storage
+              mountPath: /var/lib/postgresql/data
+      volumes:
+        - name: postgres-storage
+          persistentVolumeClaim:
+            claimName: postgres-pvc

code-samples/eventing/bookstore-sample-app/db/job.yaml

@@ -0,0 +1,24 @@
+apiVersion: batch/v1
+kind: Job
+metadata:
+  name: make-sample-table
+spec:
+  template:
+    spec:
+      containers:
+      - name: postgres-client
+        image: postgres:latest
+        command: ["psql", "-h", "postgresql", "-U", "myuser", "-d", "mydatabase", "-f", "/tmp/sample.sql", "-p", "5432", "-W"]
+        env:
+        - name: PGPASSWORD
+          value: mypassword
+        volumeMounts:
+        - name: sql-files
+          mountPath: /tmp
+          readOnly: true
+      restartPolicy: Never
+      volumes:
+      - name: sql-files
+        configMap:
+          name: sample-sql-configmap
+  backoffLimit: 4

code-samples/eventing/bookstore-sample-app/db/sample.sql

@@ -1,9 +1,9 @@
-CREATE TABLE IF NOT EXISTS book_reviews(
+CREATE TABLE IF NOT EXISTS book_reviews (
   id SERIAL PRIMARY KEY,
   post_time timestamp NOT NULL,
   content TEXT NOT NULL,
   sentiment TEXT,
-  CONSTRAINT sentiment_check CHECK (sentiment IN ('positive', 'negative', 'neutral')),
+  CONSTRAINT sentiment_check CHECK (sentiment IN ('positive', 'negative', 'neutral'))
 );
 
 INSERT INTO book_reviews (post_time, content, sentiment) VALUES 

code-samples/eventing/bookstore-sample-app/db/service.yaml

@@ -0,0 +1,10 @@
+apiVersion: v1
+kind: Service
+metadata:
+  name: postgresql
+spec:
+  ports:
+    - port: 5432
+  selector:
+    app: postgresql
+  type: NodePort