Schema Migration

Schema migration feature uses https://github.com/golang-migrate/migrate but the supported feature in mysql-operator is limited. Currently, only GitHub source is supported.

Usage

Prepare schema files. Example:
```
CREATE TABLE test_table (id int, name varchar(10));
```
```
DROP TABLE test_table;
```
https://github.com/nakamasato/mysql-operator/tree/96dc1eeaf00c8afb42f1c9b63859ff57c440e584/config/sample-migrations

Create MySQLDB yaml with schemaMigrationFromGitHub

apiVersion: mysql.nakamasato.com/v1alpha1
kind: MySQLDB
metadata:
  labels:
    app.kubernetes.io/name: mysqldb
    app.kubernetes.io/instance: mysqldb-sample
    app.kubernetes.io/part-of: mysql-operator
    app.kubernetes.io/managed-by: kustomize
    app.kubernetes.io/created-by: mysql-operator
  name: sample-db # this is not a name for MySQL database but just a Kubernetes object name
spec:
  dbName: sample_db # this is MySQL database name
  mysqlName: mysql-sample
  schemaMigrationFromGitHub:
    owner: nakamasato
    repo: mysql-operator
    path: config/sample-migrations
    ref: 96dc1eeaf00c8afb42f1c9b63859ff57c440e584 # (optional) you can write branch, tag, sha

This configuration will generate "github://nakamasato/mysql-operator/config/sample-migrations#96dc1eeaf00c8afb42f1c9b63859ff57c440e584" as sourceUrl for source/github

Run mysql & mysql-operator

docker run -d -p 3306:3306 -e MYSQL_ROOT_PASSWORD=password --rm mysql:8

make install run # to be updated with helm command

Create resources
```
kubectl apply -k config/samples
```

Check test_table is created.

docker exec -it $(docker ps | grep mysql | head -1 |awk '{print $1}') mysql -uroot -ppassword

mysql> use sample_db;
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Database changed
mysql> show tables;
+---------------------+
| Tables_in_sample_db |
+---------------------+
| schema_migrations   |
| test_table          |
+---------------------+
2 rows in set (0.00 sec)

Clean up
```
kubectl delete -k config/samples
```