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Run MySQL with Custom Configuration
KubeDB supports providing custom configuration for MySQL via PodTemplate. This tutorial will show you how to use KubeDB to run a MySQL database with custom configuration using PodTemplate.
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 minikube.
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.$ kubectl create ns demo namespace/demo created
Note: YAML files used in this tutorial are stored in docs/examples/mysql folder in GitHub repository kubedb/cli.
Overview
KubeDB allows providing a template for database pod through spec.podTemplate. KubeDB operator will pass the information provided in spec.podTemplate to the StatefulSet created for MySQL database.
KubeDB accept following fields to set in spec.podTemplate:
- metadata:
- annotations (pod’s annotation)
- controller:
- annotations (statefulset’s annotation)
- spec:
- env
- resources
- initContainers
- imagePullSecrets
- nodeSelector
- affinity
- schedulerName
- tolerations
- priorityClassName
- priority
- securityContext
Read about the fields in details in PodTemplate concept,
CRD Configuration
Below is the YAML for the MySQL created in this example. Here, spec.podTemplate.spec.env specifies environment variables and spec.podTemplate.spec.args provides extra arguments for MySQL Docker Image.
In this tutorial, an initial database myDB will be created by providing env MYSQL_DATABASE while the server character set will be set to utf8mb4 by adding extra args. Note that, character-set-server in MySQL 5.7 is latin1.
apiVersion: kubedb.com/v1alpha1
kind: MySQL
metadata:
name: mysql-misc-config
namespace: demo
spec:
version: "5.7-v1"
storageType: "Durable"
storage:
storageClassName: "standard"
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
podTemplate:
spec:
env:
- name: MYSQL_DATABASE
value: myDB
args:
- --character-set-server=utf8mb4
resources:
requests:
memory: "1Gi"
cpu: "250m"
terminationPolicy: Pause
updateStrategy:
type: RollingUpdate
$ kubedb create -f https://raw.githubusercontent.com/kubedb/cli/0.10.0/docs/examples/mysql/configuration/mysql-misc-config.yaml
mysql.kubedb.com/mysql-misc-config created
Now, wait a few minutes. KubeDB operator will create necessary PVC, statefulset, services, secret etc. If everything goes well, we will see that a pod with the name mysql-misc-config-0 has been created.
Check that the statefulset’s pod is running
$ kubectl get pod -n demo
NAME READY STATUS RESTARTS AGE
mysql-misc-config-0 1/1 Running 0 1m
Check the pod’s log to see if the database is ready
$ kubectl logs -f -n demo mysql-misc-config-0
Initializing database
.....
Database initialized
Initializing certificates
...
Certificates initialized
MySQL init process in progress...
....
MySQL init process done. Ready for start up.
....
2018-10-02T09:34:33.694994Z 0 [Note] mysqld: ready for connections.
Version: '5.7.23' socket: '/var/run/mysqld/mysqld.sock' port: 3306 MySQL Community Server (GPL)
....
Once we see [Note] /usr/sbin/mysqld: ready for connections. in the log, the database is ready.
Now, we will check if the database has started with the custom configuration we have provided.
First, deploy phpMyAdmin to connect with the MySQL database we have just created.
$ kubectl create -f https://raw.githubusercontent.com/kubedb/cli/0.10.0/docs/examples/mysql/quickstart/demo-1.yaml
deployment.extensions/myadmin created
service/myadmin created
Then, open your browser and go to the following URL: http://{cluster-ip}:{myadmin-svc-nodeport}. For minikube you can get this URL by running the following command:
$ minikube service myadmin -n demo --url
http://192.168.99.100:30039
Now, let’s connect to the database from the phpMyAdmin dashboard using the database pod IP and MySQL user password.
$ kubectl get pods mysql-misc-config-0 -n demo -o yaml | grep IP
hostIP: 10.0.2.15
podIP: 172.17.0.6
$ kubectl get secrets -n demo mysql-misc-config-auth -o jsonpath='{.data.\user}' | base64 -d
root
$ kubectl get secrets -n demo mysql-misc-config-auth -o jsonpath='{.data.\password}' | base64 -d
MLO5_fPVKcqPiEu9
Once, you have connected to the database with phpMyAdmin go to SQL tab and run sql to see all databases SHOW DATABASES; and to see charcter-set configuration SHOW VARIABLES LIKE 'char%';. You will see a database called myDB is created and also all the character-set is set to utf8mb4.
Snapshot Configuration
Snapshot also has the scope to be configured through spec.podTemplate. In this tutorial, an extra argument is passed to snapshot crd so that the backup job uses --default-character-set=utf8mb4 while taking backup.
Below is the Snapshot CRD that is deployed in this tutorial. Create a secret my-snap-secret from here for snapshot.
apiVersion: kubedb.com/v1alpha1
kind: Snapshot
metadata:
name: snap-mysql-config
namespace: demo
labels:
kubedb.com/kind: MySQL
spec:
databaseName: mysql-misc-config
storageSecretName: my-snap-secret
gcs:
bucket: kubedb-qa
podTemplate:
spec:
args:
- --all-databases
- --default-character-set=utf8mb4
$ kubedb create -f https://raw.githubusercontent.com/kubedb/cli/0.10.0/docs/examples/mysql/configuration/snapshot-misc-conf.yaml
snapshot.kubedb.com/snap-mysql-config created
$ kubedb get snap -n demo
NAME DATABASENAME STATUS AGE
snap-mysql-config mysql-misc-config Succeeded 1m
Scheduled Backups
To configure BackupScheduler, add the require changes in PodTemplate just like snapshot object.
$ kubedb edit my mysql-misc-config -n demo
apiVersion: kubedb.com/v1alpha1
kind: MySQL
metadata:
name: mysql-misc-config
namespace: demo
...
spec:
backupSchedule:
cronExpression: '@every 1m'
storageSecretName: my-snap-secret
gcs:
bucket: kubedb-qa
podTemplate:
controller: {}
metadata: {}
spec:
args:
- --all-databases
- --default-character-set=utf8mb4
resources: {}
...
status:
observedGeneration: 3$4212299729528774793
phase: Running
$ kubedb get snap -n demo
NAME DATABASENAME STATUS AGE
mysql-misc-config-20181002-105247 mysql-misc-config Succeeded 3m
mysql-misc-config-20181002-105349 mysql-misc-config Succeeded 2m
mysql-misc-config-20181002-105449 mysql-misc-config Succeeded 1m
mysql-misc-config-20181002-105549 mysql-misc-config Succeeded 43s
snap-mysql-config mysql-misc-config Succeeded 12m
Cleaning up
To cleanup the Kubernetes resources created by this tutorial, run:
kubectl patch -n demo my/mysql-misc-config -p '{"spec":{"terminationPolicy":"WipeOut"}}' --type="merge"
kubectl delete -n demo my/mysql-misc-config
kubectl patch -n demo drmn/mysql-misc-config -p '{"spec":{"wipeOut":true}}' --type="merge"
kubectl delete -n demo drmn/mysql-misc-config
kubectl delete -n demo configmap my-custom-config
kubectl delete deployment -n demo myadmin
kubectl delete service -n demo myadmin
kubectl delete ns demo
If you would like to uninstall KubeDB operator, please follow the steps here.
Next Steps
- Quickstart MySQL with KubeDB Operator.
- Snapshot and Restore process of MySQL databases using KubeDB.
- Take Scheduled Snapshot of MySQL databases using KubeDB.
- Initialize MySQL with Script.
- Initialize MySQL with Snapshot.
- Monitor your MySQL database with KubeDB using out-of-the-box CoreOS Prometheus Operator.
- Monitor your MySQL database with KubeDB using out-of-the-box builtin-Prometheus.
- Use private Docker registry to deploy MySQL with KubeDB.
- Use kubedb cli to manage databases like kubectl for Kubernetes.
- Detail concepts of MySQL object.
- Detail concepts of Snapshot object.
- Want to hack on KubeDB? Check our contribution guidelines.