MySQL

MySQL is one of the most popular database servers in the world. Notable users include Wikipedia, Facebook and Google.

Introduction

This chart bootstraps a single node MySQL deployment on a Kubernetes cluster using the Helm package manager.

Prerequisites

• Kubernetes 1.6+ with Beta APIs enabled
• PV provisioner support in the underlying infrastructure

Installing the Chart

To install the chart with the release name my-release:

$ helm install --name my-release stable/mysql

The command deploys MySQL on the Kubernetes cluster in the default configuration. The configuration section lists the parameters that can be configured during installation.

By default a random password will be generated for the root user. If you'd like to set your own password change the mysqlRootPasswordin the values.yaml.

You can retrieve your root password by running the following command. Make sure to replace [YOUR_RELEASE_NAME]:

printf $(printf '\%o' `kubectl get secret [YOUR_RELEASE_NAME]-mysql -o jsonpath="{.data.mysql-root-password[*]}"`)

Tip: List all releases using helm list

Uninstalling the Chart

To uninstall/delete the my-release deployment:

$ helm delete my-release

The command removes all the Kubernetes components associated with the chart and deletes the release.

Configuration

The following table lists the configurable parameters of the MySQL chart and their default values.

Some of the parameters above map to the env variables defined in the MySQL DockerHub image.

Specify each parameter using the --set key=value[,key=value] argument to helm install. For example,

$ helm install --name my-release   --set mysqlRootPassword=secretpassword,mysqlUser=my-user,mysqlPassword=my-password,mysqlDatabase=my-database     stable/mysql

The above command sets the MySQL root account password to secretpassword. Additionally it creates a standard database user named my-user, with the password my-password, who has access to a database named my-database.

Alternatively, a YAML file that specifies the values for the parameters can be provided while installing the chart. For example,

$ helm install --name my-release -f values.yaml stable/mysql

Tip: You can use the default values.yaml

Persistence

The MySQL image stores the MySQL data and configurations at the /var/lib/mysql path of the container.

By default a PersistentVolumeClaim is created and mounted into that directory. In order to disable this functionalityyou can change the values.yaml to disable persistence and use an emptyDir instead.

"An emptyDir volume is first created when a Pod is assigned to a Node, and exists as long as that Pod is running on that node. When a Pod is removed from a node for any reason, the data in the emptyDir is deleted forever."

Custom MySQL configuration files

The MySQL image accepts custom configuration files at the path /etc/mysql/conf.d. If you want to use a customized MySQL configuration, you can create your alternative configuration files by passing the file contents on the configurationFiles attribute. Note that according to the MySQL documentation only files ending with .cnf are loaded.

configurationFiles:  mysql.cnf: |-    [mysqld]    skip-host-cache    skip-name-resolve    sql-mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION  mysql_custom.cnf: |-    [mysqld]

MySQL initialization files

The MySQL image accepts .sh, .sql and *.sql.gz files at the path /docker-entrypoint-initdb.d.These files are being run exactly once for container initialization and ignored on following container restarts.If you want to use initialization scripts, you can create initialization files by passing the file contents on the initializationFiles attribute.

initializationFiles:  first-db.sql: |-    CREATE DATABASE IF NOT EXISTS first DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;  second-db.sql: |-    CREATE DATABASE IF NOT EXISTS second DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;

SSL

This chart supports configuring MySQL to use encrypted connections with TLS/SSL certificates provided by the user. This is accomplished by storing the required Certificate Authority file, the server public key certificate, and the server private key as a Kubernetes secret. The SSL options for this chart support the following use cases:

• Manage certificate secrets with helm
• Manage certificate secrets outside of helm

Manage certificate secrets with helm

Include your certificate data in the ssl.certificates section. For example:

ssl:  enabled: false  secret: mysql-ssl-certs  certificates:  - name: mysql-ssl-certs    ca: |-      -----BEGIN CERTIFICATE-----      ...      -----END CERTIFICATE-----    cert: |-      -----BEGIN CERTIFICATE-----      ...      -----END CERTIFICATE-----    key: |-      -----BEGIN RSA PRIVATE KEY-----      ...      -----END RSA PRIVATE KEY-----

Note: Make sure your certificate data has the correct formatting in the values file.

Manage certificate secrets outside of helm

1. Ensure the certificate secret exist before installation of this chart.
2. Set the name of the certificate secret in ssl.secret.
3. Make sure there are no entries underneath ssl.certificates.

To manually create the certificate secret from local files you can execute:

kubectl create secret generic mysql-ssl-certs   --from-file=ca.pem=./ssl/certificate-authority.pem   --from-file=server-cert.pem=./ssl/server-public-key.pem   --from-file=server-key.pem=./ssl/server-private-key.pem

Note: ca.pem, server-cert.pem, and server-key.pem must be used as the key names in this generic secret.

If you are using a certificate your configurationFiles must include the three ssl lines under [mysqld]

[mysqld]    ssl-ca=/ssl/ca.pem    ssl-cert=/ssl/server-cert.pem    ssl-key=/ssl/server-key.pem