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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
demothroughout 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/v2024.11.18/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 3m14sThen, 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/v1
kind: MySQL
metadata:
name: mysql-init-script
namespace: demo
spec:
version: "8.0.35"
topology:
mode: GroupReplication
replicas: 3
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/v2024.11.18/docs/guides/mysql/initialization/yamls/initialize-gr.yaml
mysql.kubedb.com/mysql-init-script created
apiVersion: kubedb.com/v1
kind: MySQL
metadata:
name: mysql-init-script
namespace: demo
spec:
version: "8.0.31-innodb"
replicas: 3
topology:
mode: InnoDBCluster
innoDBCluster:
router:
replicas: 1
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/v2024.11.18/docs/guides/mysql/initialization/yamls/initialize-innodb.yaml
mysql.kubedb.com/mysql-init-script created
apiVersion: kubedb.com/v1
kind: MySQL
metadata:
name: mysql-init-script
namespace: demo
spec:
version: "8.0.35"
replicas: 3
topology:
mode: SemiSync
semiSync:
sourceWaitForReplicaCount: 1
sourceTimeout: 23h
errantTransactionRecoveryPolicy: PseudoTransaction
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/v2024.11.18/docs/guides/mysql/initialization/yamls/initialize-mysql.yaml
mysql.kubedb.com/mysql-init-script created
apiVersion: kubedb.com/v1
kind: MySQL
metadata:
name: mysql-init-script
namespace: demo
spec:
version: "8.0.35"
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/v2024.11.18/docs/guides/mysql/initialization/yamls/initialize-mysql.yaml
mysql.kubedb.com/mysql-init-script created
Here,
spec.init.scriptspecifies a script source used to initialize the database before database server starts. The scripts will be executed alphabetically. In this tutorial, a sample .sql script from the git repositoryhttps://github.com/kubedb/mysql-init-scripts.gitis 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 alphabetically. 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 PetSet and a Service with the matching MySQL object name. KubeDB operator will also create a governing service for PetSets 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, 30 Jun 2022 12:21:15 +0600
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration={"apiVersion":"kubedb.com/v1","kind":"MySQL","metadata":{"annotations":{},"name":"mysql-init-script","namespace":"demo"},"spec":{"init":{"script"...
Replicas: 1 total
Status: Provisioning
StorageType: Durable
Volume:
StorageClass: standard
Capacity: 1Gi
Access Modes: RWO
Paused: false
Halted: false
Termination Policy: Delete
PetSet:
Name: mysql-init-script
CreationTimestamp: Thu, 30 Jun 2022 12:21:15 +0600
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=mysql-init-script
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
Annotations: <none>
Replicas: 824644789336 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/instance=mysql-init-script
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
Annotations: <none>
Type: ClusterIP
IP: 10.96.198.184
Port: primary 3306/TCP
TargetPort: db/TCP
Endpoints: 10.244.0.23:3306
Service:
Name: mysql-init-script-pods
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=mysql-init-script
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
Annotations: <none>
Type: ClusterIP
IP: None
Port: db 3306/TCP
TargetPort: db/TCP
Endpoints: 10.244.0.23:3306
Auth Secret:
Name: mysql-init-script-auth
Labels: app.kubernetes.io/component=database
app.kubernetes.io/instance=mysql-init-script
app.kubernetes.io/managed-by=kubedb.com
app.kubernetes.io/name=mysqls.kubedb.com
Annotations: <none>
Type: kubernetes.io/basic-auth
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/v1","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":"8.0.35"}}
Creation Timestamp: 2022-06-30T06:21:15Z
Labels:
app.kubernetes.io/component: database
app.kubernetes.io/instance: mysql-init-script
app.kubernetes.io/managed-by: kubedb.com
app.kubernetes.io/name: mysqls.kubedb.com
Name: mysql-init-script
Namespace: demo
Spec:
Client Config:
Service:
Name: mysql-init-script
Path: /
Port: 3306
Scheme: mysql
URL: tcp(mysql-init-script.demo.svc:3306)/
Parameters:
API Version: appcatalog.appscode.com/v1alpha1
Kind: StashAddon
Stash:
Addon:
Backup Task:
Name: mysql-backup-8.0.21
Params:
Name: args
Value: --all-databases --set-gtid-purged=OFF
Restore Task:
Name: mysql-restore-8.0.21
Secret:
Name: mysql-init-script-auth
Type: kubedb.com/mysql
Version: 8.0.35
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Successful 10s KubeDB operator Successfully created governing service
Normal Successful 10s KubeDB operator Successfully created service for primary/standalone
Normal Successful 10s KubeDB operator Successfully created database auth secret
Normal Successful 10s KubeDB operator Successfully created PetSet
Normal Successful 10s KubeDB operator Successfully created MySQL
Normal Successful 10s KubeDB operator Successfully created appbinding
$ kubectl get petset -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-pods 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/v1
kind: MySQL
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"kubedb.com/v1","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":"8.0.35"}}
creationTimestamp: "2022-06-30T06:21:15Z"
finalizers:
- kubedb.com
generation: 3
name: mysql-init-script
namespace: demo
resourceVersion: "1697522"
uid: 932c1fe3-6692-4ddc-b4cd-fe34e0d5ebc8
spec:
allowedReadReplicas:
namespaces:
from: Same
allowedSchemas:
namespaces:
from: Same
authSecret:
name: mysql-init-script-auth
init:
initialized: true
script:
configMap:
name: my-init-script
podTemplate:
controller: {}
metadata: {}
spec:
affinity:
...
resources:
limits:
memory: 1Gi
requests:
cpu: 500m
memory: 1Gi
serviceAccountName: mysql-init-script
replicas: 1
storage:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: standard
storageType: Durable
deletionPolicy: Delete
useAddressType: DNS
version: 8.0.35
status:
conditions:
...
observedGeneration: 2
reason: DatabaseSuccessfullyProvisioned
status: "True"
type: Provisioned
observedGeneration: 2
phase: Ready
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 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":{"deletionPolicy":"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.