In this blog I will demonstrate how to deploy PostgreSQL DB server and pgadmin in Kubernetes.
PostgreSQL, also known as Postgres, is a free and open-source relational database management system emphasizing extensibility and SQL compliance. It was originally named POSTGRES, referring to its origins as a successor to the Ingres database developed at the University of California, Berkeley.
PGAdmin is a web-based GUI tool used to interact with the Postgres database sessions, both locally and remote servers as well. You can use PGAdmin to perform any sort of database administration required for a Postgres database.
Kubernetes is an open-source container orchestration system for automating software deployment, scaling, and management. Google originally designed Kubernetes, but the Cloud Native Computing Foundation now maintains the project.
A Kubernetes cluster can be deployed on either physical or virtual machines. I will use Minikube for Kubernetes development.
Minikube is a lightweight Kubernetes implementation that creates a VM on your local machine and deploys a simple cluster containing only one node. Minikube is available for Linux, macOS, and Windows systems.
Step #1
Install minikube, make sure it’s started
minikube start
* minikube v1.28.0 on Ubuntu 20.04 (vbox/amd64)
* Automatically selected the docker driver
* Using Docker driver with root privileges
* Starting control plane node minikube in cluster minikube
* Pulling base image ...
* Creating docker container (CPUs=2, Memory=2200MB) ...
* Preparing Kubernetes v1.25.3 on Docker 20.10.20 ...
- Generating certificates and keys ...
- Booting up control plane ...
- Configuring RBAC rules ...
* Verifying Kubernetes components...
- Using image gcr.io/k8s-minikube/storage-provisioner:v5
* Enabled addons: storage-provisioner, default-storageclass
* Done! kubectl is now configured to use "minikube" cluster and "default" namespace by default
dmi@dmi-VirtualBox:~/my-postgres-and-pgadmin-deployment$
Tip. If you want to reset and restart your entire Kubernetes cluster in Minikube run the following command:
minikube delete
* Deleting "minikube" in docker ...
* Deleting container "minikube" ...
* Removing /home/dmi/.minikube/machines/minikube ...
* Removed all traces of the "minikube" cluster.
Step #2
Encode PostgreSQL admin username and password using base64:
echo -n 'root' | base64
cm9vdA==
echo -n 'mypassword' | base64
bXlwYXNzd29yZA==
Step #3
Create and apply postgres-secret.yaml file:
apiVersion: v1
kind: Secret
metadata:
name: postgres-secret
labels:
app: postgres
type: Opaque
data:
postgres-root-username: cm9vdA==
postgres-root-password: bXlwYXNzd29yZA==
kubectl apply -f postgres-secret.yaml
secret/postgres-secret created
Step #4
Create and apply postgres-configmap.yaml file:
apiVersion: v1
kind: ConfigMap
metadata:
name: postgres-configmap
labels:
app: postgres
data:
postgres-dbname: mydb
postgres-configmap.yaml
configmap/postgres-configmap created
Step #5
Create and apply postgres-deploy.yaml file:
apiVersion: apps/v1
kind: Deployment
metadata:
name: postgres
spec:
selector:
matchLabels:
app: postgres
replicas: 1
template:
metadata:
labels:
app: postgres
spec:
containers:
- name: postgres
image: postgres:latest
imagePullPolicy: "IfNotPresent"
env:
- name: POSTGRES_USER
valueFrom:
secretKeyRef:
name: postgres-secret
key: postgres-root-username
- name: POSTGRES_PASSWORD
valueFrom:
secretKeyRef:
name: postgres-secret
key: postgres-root-password
- name: POSTGRES_DB
valueFrom:
configMapKeyRef:
name: postgres-configmap
key: postgres-dbname
volumeMounts:
- mountPath: /var/lib/postgresql/data
name: postgredb
volumes:
- name: postgredb
persistentVolumeClaim:
claimName: postgres-pv-claim
---
kind: PersistentVolume
apiVersion: v1
metadata:
name: postgres-pv-volume
labels:
type: local
app: postgres
spec:
storageClassName: manual
capacity:
storage: 5Gi
accessModes:
- ReadWriteMany
hostPath:
path: "/mnt/data"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: postgres-pv-claim
labels:
app: postgres
spec:
storageClassName: manual
accessModes:
- ReadWriteMany
resources:
requests:
storage: 5Gi
---
apiVersion: v1
kind: Service
metadata:
name: postgres
labels:
app: postgres
spec:
ports:
- name: postgres
port: 5432
nodePort: 30432
type: NodePort
selector:
app: postgres
kubectl apply -f postgres-deploy.yaml
deployment.apps/postgres created
persistentvolume/postgres-pv-volume created
persistentvolumeclaim/postgres-pv-claim created
service/postgres created
Step #6
Ensure PostgreSQL pod is up, and its related service is up.
kubectl get all
NAME READY STATUS RESTARTS AGE
pod/postgres-5c7d8b656d-xj5b2 1/1 Running 0 61s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11m
service/postgres NodePort 10.104.238.217 <none> 5432:30432/TCP 61s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/postgres 1/1 1 1 62s
NAME DESIRED CURRENT READY AGE
replicaset.apps/postgres-5c7d8b656d 1 1 1 62s
dmi@dmi-VirtualBox:~/my-postgres-and-pgadmin-deployment$
Step #7
Connect to the PostgreSQL to ensure it's up and running.
minikube service postgres
|-----------|----------|---------------|---------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|----------|---------------|---------------------------|
| default | postgres | postgres/5432 | http://192.168.49.2:30432 |
|-----------|----------|---------------|---------------------------|
kubectl get pods
NAME READY STATUS RESTARTS AGE
postgres-5c7d8b656d-xj5b2 1/1 Running 0 4m5s
kubectl exec -it postgres-5c7d8b656d-xj5b2 -- /bin/bash
root@postgres-5c7d8b656d-xj5b2:/# psql -U root -d mydb -W
Password:
psql (15.1 (Debian 15.1-1.pgdg110+1))
Type "help" for help.
mydb=# select version();
version
-----------------------------------------------------------------------------------------------------------------------------
PostgreSQL 15.1 (Debian 15.1-1.pgdg110+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit
(1 row)
mydb=# create table my_table(a varchar(100));
CREATE TABLE
mydb=# insert into my_table values('1234567890');
INSERT 0 1
mydb=# select * from my_table;
a
------------
1234567890
(1 row)
mydb=#
Step #8
To access PostgreSQL logs placed in the pod use the following approach:
kubectl get pod
NAME READY STATUS RESTARTS AGE
postgres-5c7d8b656d-xj5b2 1/1 Running 0 7m28s
dmi@dmi-VirtualBox:~/my-postgres-and-pgadmin-deployment$ kubectl logs postgres-5c7d8b656d-xj5b2
...
PostgreSQL init process complete; ready for start up.
2022-12-10 20:10:26.914 UTC [1] LOG: starting PostgreSQL 15.1 (Debian 15.1-1.pgdg110+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 10.2.1-6) 10.2.1 20210110, 64-bit
2022-12-10 20:10:26.935 UTC [1] LOG: listening on IPv4 address "0.0.0.0", port 5432
2022-12-10 20:10:26.935 UTC [1] LOG: listening on IPv6 address "::", port 5432
2022-12-10 20:10:26.943 UTC [1] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
2022-12-10 20:10:26.956 UTC [64] LOG: database system was shut down at 2022-12-10 20:10:26 UTC
2022-12-10 20:10:26.965 UTC [1] LOG: database system is ready to accept connections
...
2022-12-10 20:15:27.055 UTC [62] LOG: checkpoint starting: time
2022-12-10 20:15:31.232 UTC [62] LOG: checkpoint complete: wrote 44 buffers (0.3%); 0 WAL file(s) added, 0 removed, 0 recycled; write=4.148 s, sync=0.017 s, total=4.177 s; sync files=12, longest=0.004 s, average=0.002 s; distance=252 kB, estimate=252 kB
dmi@dmi-VirtualBox:~/my-postgres-and-pgadmin-deployment$
Step #9
Generate password for pgadmin login:
echo -n 'mypwd' | base64
bXlwd2Q=
Step #10
Create yaml file pgadmin-secret.yaml and apply it:
apiVersion: v1
kind: Secret
metadata:
name: pgadmin-secret
type: Opaque
data:
pgadmin-default-password: bXlwd2Q=
kubectl apply -f pgadmin-secret.yaml
secret/pgadmin-secret created
Step #11
Create and apply pgadmin-deploy.yaml file:
apiVersion: apps/v1
kind: Deployment
metadata:
name: pgadmin
spec:
selector:
matchLabels:
app: pgadmin
replicas: 1
template:
metadata:
labels:
app: pgadmin
spec:
containers:
- name: pgadmin4
image: dpage/pgadmin4
env:
- name: PGADMIN_DEFAULT_EMAIL
value: "admin@admin.com"
- name: PGADMIN_DEFAULT_PASSWORD
valueFrom:
secretKeyRef:
name: pgadmin-secret
key: pgadmin-default-password
- name: PGADMIN_PORT
value: "80"
ports:
- containerPort: 80
name: pgadminport
---
apiVersion: v1
kind: Service
metadata:
name: pgadmin
labels:
app: pgadmin
spec:
selector:
app: pgadmin
type: NodePort
ports:
- port: 80
nodePort: 30200
Step #12
kubectl apply -f pgadmin-deploy.yaml
deployment.apps/pgadmin created
service/pgadmin created
Step #13
Ensure the relevant pods and services are up and running:
kubectl get all
NAME READY STATUS RESTARTS AGE
pod/pgadmin-b8fff9cb9-l4xkq 1/1 Running 0 51s
pod/postgres-5c7d8b656d-xj5b2 1/1 Running 0 14m
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 24m
service/pgadmin NodePort 10.101.165.6 <none> 80:30200/TCP 51s
service/postgres NodePort 10.104.238.217 <none> 5432:30432/TCP 14m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/pgadmin 1/1 1 1 51s
deployment.apps/postgres 1/1 1 1 14m
NAME DESIRED CURRENT READY AGE
replicaset.apps/pgadmin-b8fff9cb9 1 1 1 51s
replicaset.apps/postgres-5c7d8b656d 1 1 1 14m
dmi@dmi-VirtualBox:~/my-postgres-and-pgadmin-deployment$
Step #14
Access the newly created PostgreSQL DB Server using pgadmin.
minikube service pgadmin
|-----------|---------|-------------|---------------------------|
| NAMESPACE | NAME | TARGET PORT | URL |
|-----------|---------|-------------|---------------------------|
| default | pgadmin | 80 | http://192.168.49.2:30200 |
|-----------|---------|-------------|---------------------------|
* Opening service default/pgadmin in default browser...
Conclusion
In this blog I've demonstrated how to deploy PostgreSQL DB Server and PGadmin in Kubernetes cluster. I believe this information will be helpful and valuable.
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