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Initialize MariaDB using Script
This tutorial will show you how to use KubeDB to initialize a MariaDB database with *.sql, *.sh and/or *.sql.gz script. In this tutorial we will use .sql script stored in GitHub repository kubedb/mysql-init-scripts.
Note: The yaml files that are used in this tutorial are stored here folder in GitHub repository kubedb/docs.
Before You Begin
At first, you need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. If you do not already have a cluster, you can create one by using kind.
Now, install KubeDB cli on your workstation and KubeDB operator in your cluster following the steps here.
To keep things isolated, this tutorial uses a separate namespace called
demo
throughout this tutorial.
$ kubectl create ns demo
namespace/demo created
Prepare Initialization Scripts
MariaDB supports initialization with .sh
, .sql
and .sql.gz
files. In this tutorial, we will use init.sql
script from mysql-init-scripts git repository to create a TABLE kubedb_table
in mysql
database.
We will use a ConfigMap as script source. You can use any Kubernetes supported volume as script source.
At first, we will create a ConfigMap from init.sql
file. Then, we will provide this ConfigMap as script source in init.script
of MariaDB crd spec.
Let’s create a ConfigMap with initialization script,
$ kubectl create configmap -n demo md-init-script \
--from-literal=init.sql="$(curl -fsSL https://github.com/kubedb/mysql-init-scripts/raw/master/init.sql)"
configmap/md-init-script created
Create a MariaDB database with Init-Script
Below is the MariaDB
object created in this tutorial.
apiVersion: kubedb.com/v1
kind: MariaDB
metadata:
name: sample-mariadb
namespace: demo
spec:
version: "10.5.23"
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
init:
script:
configMap:
name: md-init-script
deletionPolicy: WipeOut
$ kubectl create -f https://github.com/kubedb/docs/raw/v2024.11.18/docs/examples/mysql/Initialization/demo-1.yaml
mysql.kubedb.com/mysql-init-script created
Here,
spec.init.script
specifies a script source used to initialize the database before database server starts. The scripts will be executed alphabatically. In this tutorial, a sample .sql script from the git repositoryhttps://github.com/kubedb/mysql-init-scripts.git
is used to create a test database. You can use other volume sources instead ofConfigMap
. The *.sql, *sql.gz and/or *.sh sripts that are stored inside the root folder will be executed alphabatically. The scripts inside child folders will be skipped.
KubeDB operator watches for MariaDB
objects using Kubernetes api. When a MariaDB
object is created, KubeDB operator will create a new PetSet and a Service with the matching MariaDB object name. KubeDB operator will also create a governing service for PetSets with the name kubedb
, if one is not already present. No MariaDB specific RBAC roles are required for RBAC enabled clusters.
$ kubectl get mariadb -n demo sample-mariadb -oyaml
apiVersion: kubedb.com/v1
kind: MariaDB
metadata:
...
name: sample-mariadb
namespace: demo
...
spec:
authSecret:
name: sample-mariadb-auth
init:
initialized: true
script:
configMap:
name: md-init-script
...
replicas: 1
storage:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: standard
storageType: Durable
deletionPolicy: WipeOut
version: 10.5.23
status:
...
phase: Ready
KubeDB operator sets the status.phase
to Ready
once the database is successfully created.
Now, we will connect to this database and check the data inserted by the initlization script.
# Connecting to the database
$ kubectl exec -it -n demo sample-mariadb-0 -- bash
root@sample-mariadb-0:/ mysql -u${MYSQL_ROOT_USERNAME} -p${MYSQL_ROOT_PASSWORD}
Welcome to the MariaDB monitor. Commands end with ; or \g.
Your MariaDB connection id is 40
Server version: 10.5.23-MariaDB-1:10.5.23+maria~focal mariadb.org binary distribution
Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
MariaDB [(none)]> use mysql;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
# Showing the inserted `kubedb_table`
Database changed
MariaDB [mysql]> select * from kubedb_table;
+----+-------+
| id | name |
+----+-------+
| 1 | name1 |
| 2 | name2 |
| 3 | name3 |
+----+-------+
3 rows in set (0.001 sec)
MariaDB [mysql]> quit;
Bye
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
$ kubectl delete mariadb -n demo sample-mariadb
mariadb.kubedb.com "sample-mariadb" deleted
$ kubectl delete ns demo
namespace "demo" deleted