How to deploy a simple Postgres DB to a Kubernetes cluster

This is a simple guide on how to deploy and create a Postgres database. Note, this is not ready for any production purpose.

Create a Kubernetes Deployment

Note: Openshift environments may first need to change the security context constraints to allow Postgres to perform root operations. To do this, run:

oc adm policy add-scc-to-user anyuid -z default 

To create a configmap, persist data, deploy Postgres to kubernetes and create a service, run the following commands:

kubectl create -f postgres-configmap.yaml
kubectl create -f postgres-storage.yaml
kubectl create -f postgres-deployment.yaml
kubectl create -f postgres-service.yaml

Test the connection

Connection credentials available in the postgres-configmap.yaml descriptor.

kubectl get svc postgres

To connect to the PostgreSQL database, run the command below, changing the pod name:

kubectl exec -it postgres-xxxx -- psql -h postgres -U postgresadmin --password -p 5432 postgresdb

You will be prompted for password. Connection credentials are in the postgres-configmap.yaml file.
After you enter your password, you should get a PostgreSQL shell

Create a testdb database with a test table

Run the command below in the PostgreSQL shell to both create a new database and switch to it. Enter the previous password when prompted:

CREATE DATABASE testdb;
\c testdb;

To create a table and populate it, run:

CREATE TABLE test (data TEXT PRIMARY KEY);
INSERT INTO test(data) VALUES ('hello'), ('world');

Read the test table from the testdb database

SELECT * FROM test;

You should see 2 rows containing ‘hello’ and ‘world’ respectively. Enter exit to exit the shell.
Our testdb database works fine and can now be used in a Camel K integration.