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Initialize MySQL using Script
This tutorial will show you how to use KubeDB to initialize a MySQL 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 in docs/guides/mysql/initialization/yamls 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. This tutorial will also use a phpMyAdmin to connect and test MySQL database, once it is running. Run the following command to prepare your cluster for this tutorial:$ kubectl create ns demo namespace/demo created $ kubectl create -f https://github.com/kubedb/docs/raw/v2021.12.21/docs/guides/mysql/initialization/yamls/phpmyadmin.yaml deployment.extensions/myadmin created service/myadmin created $ kubectl get pods -n demo NAME READY STATUS RESTARTS AGE myadmin-66cc8d4c77-wkwht 1/1 Running 0 5m20s $ kubectl get service -n demo NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE myadmin LoadBalancer 10.104.142.213 <pending> 80:31529/TCP 3m14s
Then, open your browser and go to the following URL: http://{node-ip}:{myadmin-svc-nodeport}. For kind cluster, you can get this URL by running the following command:
$ kubectl get svc -n demo myadmin -o json | jq '.spec.ports[].nodePort' 31529 $ kubectl get node -o json | jq '.items[].status.addresses[].address' "172.18.0.3" "kind-control-plane" "172.18.0.4" "kind-worker" "172.18.0.2" "kind-worker2" # expected url will be: url: http://172.18.0.4:31529
Prepare Initialization Scripts
MySQL 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 MySQL crd spec.
Let’s create a ConfigMap with initialization script,
$ kubectl create configmap -n demo my-init-script \
--from-literal=init.sql="$(curl -fsSL https://github.com/kubedb/mysql-init-scripts/raw/master/init.sql)"
configmap/my-init-script created
Create a MySQL database with Init-Script
Below is the MySQL
object created in this tutorial.
apiVersion: kubedb.com/v1alpha2
kind: MySQL
metadata:
name: mysql-init-script
namespace: demo
spec:
version: "8.0.27"
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
init:
script:
configMap:
name: my-init-script
$ kubectl create -f https://github.com/kubedb/docs/raw/v2021.12.21/docs/guides/mysql/initialization/yamls/initialize-mysql.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 MySQL
objects using Kubernetes api. When a MySQL
object is created, KubeDB operator will create a new StatefulSet and a Service with the matching MySQL object name. KubeDB operator will also create a governing service for StatefulSets with the name kubedb
, if one is not already present. No MySQL specific RBAC roles are required for RBAC enabled clusters.
$ kubectl dba describe my -n demo mysql-init-scrip
Name: mysql-init-script
Namespace: demo
CreationTimestamp: Thu, 27 Aug 2020 12:42:04 +0600
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"kubedb.com/v1alpha2","kind":"MySQL","metadata":{"annotations":{},"name":"mysql-init-script","namespace":"demo"},"spec":{"init":{"scriptS...
Replicas: 1 total
Status: Running
StorageType: Durable
Volume:
StorageClass: standard
Capacity: 1Gi
Access Modes: RWO
Halted: false
Halted: false
Termination Policy: Delete
StatefulSet:
Name: mysql-init-script
CreationTimestamp: Thu, 27 Aug 2020 12:42:04 +0600
Labels: app.kubernetes.io/component=database
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
app.kubernetes.io/instance=mysql-init-script
Annotations: <none>
Replicas: 824637371096 desired | 1 total
Pods Status: 1 Running / 0 Waiting / 0 Succeeded / 0 Failed
Service:
Name: mysql-init-script
Labels: app.kubernetes.io/component=database
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
app.kubernetes.io/instance=mysql-init-script
Annotations: <none>
Type: ClusterIP
IP: 10.103.202.117
Port: db 3306/TCP
TargetPort: db/TCP
Endpoints: 10.244.2.9:3306
Service:
Name: mysql-init-script-gvr
Labels: app.kubernetes.io/component=database
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
app.kubernetes.io/instance=mysql-init-script
Annotations: service.alpha.kubernetes.io/tolerate-unready-endpoints=true
Type: ClusterIP
IP: None
Port: db 3306/TCP
TargetPort: 3306/TCP
Endpoints: 10.244.2.9:3306
Database Secret:
Name: mysql-init-script-auth
Labels: app.kubernetes.io/component=database
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
app.kubernetes.io/instance=mysql-init-script
Annotations: <none>
Type: Opaque
Data:
password: 16 bytes
username: 4 bytes
Init:
Script Source:
Volume:
Type: ConfigMap (a volume populated by a ConfigMap)
Name: my-init-script
Optional: false
AppBinding:
Metadata:
Annotations:
kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"kubedb.com/v1alpha2","kind":"MySQL","metadata":{"annotations":{},"name":"mysql-init-script","namespace":"demo"},"spec":{"init":{"script":{"configMap":{"name":"my-init-script"}}},"storage":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"},"version":"8.0.27"}}
Creation Timestamp: 2020-08-27T06:43:15Z
Labels:
app.kubernetes.io/component: database
app.kubernetes.io/instance: mysql-init-script
app.kubernetes.io/managed-by: kubedb.com
app.kubernetes.io/name: mysql
app.kubernetes.io/version: 8.0.27
app.kubernetes.io/name: mysqls.kubedb.com
app.kubernetes.io/instance: mysql-init-script
Name: mysql-init-script
Namespace: demo
Spec:
Client Config:
Service:
Name: mysql-init-script
Path: /
Port: 3306
Scheme: mysql
URL: tcp(mysql-init-script:3306)/
Secret:
Name: mysql-init-script-auth
Type: kubedb.com/mysql
Version: 8.0.27
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Successful 1m MySQL operator Successfully created Service
Normal Successful 7s MySQL operator Successfully created StatefulSet
Normal Successful 7s MySQL operator Successfully created MySQL
Normal Successful 7s MySQL operator Successfully created appbinding
$ kubectl get statefulset -n demo
NAME READY AGE
mysql-init-script 1/1 2m24s
$ kubectl get pvc -n demo
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
data-mysql-init-script-0 Bound pvc-32a59975-2972-4122-9635-22fe19483145 1Gi RWO standard 3m
$ kubectl get pv -n demo
NAME CAPACITY ACCESS MODES RECLAIM POLICY STATUS CLAIM STORAGECLASS REASON AGE
pvc-32a59975-2972-4122-9635-22fe19483145 1Gi RWO Delete Bound demo/data-mysql-init-script-0 standard 3m25s
$ kubectl get service -n demo
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
myadmin LoadBalancer 10.104.142.213 <pending> 80:31529/TCP 23m
mysql-init-script ClusterIP 10.103.202.117 <none> 3306/TCP 3m49s
mysql-init-script-gvr ClusterIP None <none> 3306/TCP 3m49s
KubeDB operator sets the status.phase
to Running
once the database is successfully created. Run the following command to see the modified MySQL object:
$ kubectl get my -n demo mysql-init-script -o yaml
apiVersion: kubedb.com/v1alpha2
kind: MySQL
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"kubedb.com/v1alpha2","kind":"MySQL","metadata":{"annotations":{},"name":"mysql-init-script","namespace":"demo"},"spec":{"init":{"script":{"configMap":{"name":"my-init-script"}}},"storage":{"accessModes":["ReadWriteOnce"],"resources":{"requests":{"storage":"1Gi"}},"storageClassName":"standard"},"version":"8.0.27"}}
creationTimestamp: "2020-08-27T06:42:04Z"
finalizers:
- kubedb.com
generation: 2
operation: Update
time: "2020-08-27T06:43:15Z"
name: mysql-init-script
namespace: demo
resourceVersion: "11901"
selfLink: /apis/kubedb.com/v1alpha2/namespaces/demo/mysqls/mysql-init-script
uid: 2903f636-09cb-4299-af5d-c7a2e799ec61
spec:
authSecret:
name: mysql-init-script-auth
init:
script:
configMap:
name: my-init-script
podTemplate:
controller: {}
metadata: {}
spec:
resources: {}
serviceAccountName: mysql-init-script
replicas: 1
storage:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: standard
storageType: Durable
terminationPolicy: Delete
version: 8.0.27
status:
observedGeneration: 2
phase: Running
KubeDB operator has created a new Secret called mysql-init-script-auth
(format: {mysql-object-name}-auth) for storing the password for MySQL superuser. This secret contains a username
key which contains the username for MySQL superuser and a password
key which contains the password for MySQL superuser.
If you want to use an existing secret please specify that when creating the MySQL object using spec.authSecret.name
. While creating this secret manually, make sure the secret contains these two keys containing data username
and password
and also make sure of using root
as value of username
.
Now, you can connect to this database from the phpMyAdmin dashboard using the database pod IP and and mysql
user password.
$ kubectl get pods mysql-init-script-0 -n demo -o yaml | grep IP
hostIP: 10.0.2.15
podIP: 10.244.2.9
$ kubectl get secrets -n demo mysql-init-script-auth -o jsonpath='{.data.\user}' | base64 -d
root
$ kubectl get secrets -n demo mysql-init-script-auth -o jsonpath='{.data.\password}' | base64 -d
1Pc7bwSygrv1MX1Q
Note: In MySQL: 8.0.14-v1
connection to phpMyAdmin may give error as it is using caching_sha2_password
and sha256_password
authentication plugins over mysql_native_password
. If the error happens do the following for work around. But, It’s not recommended to change authentication plugins. See here for alternative solutions.
kubectl exec -it -n demo mysql-quickstart-0 -- mysql -u root --password=1Pc7bwSygrv1MX1Q -e "ALTER USER root IDENTIFIED WITH mysql_native_password BY '1Pc7bwSygrv1MX1Q';"
Now, open your browser and go to the following URL: http://{node-ip}:{myadmin-svc-nodeport}. To log into the phpMyAdmin, use host 10.244.2.9
, username root
and password 1Pc7bwSygrv1MX1Q
.
As you can see here, the initial script has successfully created a table named kubedb_table
in mysql
database and inserted three rows of data into that table successfully.
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
kubectl patch -n demo mysql/mysql-init-script -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
kubectl delete -n demo mysql/mysql-init-script
kubectl delete ns demo
Next Steps
- Initialize MySQL with Script.
- Monitor your MySQL database with KubeDB using out-of-the-box Prometheus operator.
- Monitor your MySQL database with KubeDB using out-of-the-box builtin-Prometheus.
- Use private Docker registry to deploy MySQL with KubeDB.
- Detail concepts of MySQL object.
- Detail concepts of MySQLVersion object.
- Want to hack on KubeDB? Check our contribution guidelines.