Unable to dynamically provision a GORM-capable data source in Grails 3 - spring

Question

We are implementing a multitenant application (database per tenant) and would like to include dynamic provisioning of new tenants without restarting the server. This is Grails 3.2.9 / GORM 6.
Among other things this involves creating a dataSource at runtime, without it being configured in application.yml at the application startup.
According to the documentation (11.2.5. Adding Tenants at Runtime) there exists ConnectionSources API for adding tenants at runtime, but the ConnectionSource created this way doesn't seem to be properly registered with Spring (beans for the dataSource, session and transaction manager) and Grails complain about missing beans when we try to use the new datasource.
We expect that when we use the ConnectionSources API to create a connection source for a new database, Grails should initialise it with all the tables according to the GORM Domains in our application, execute Bootstrap.groovy, etc., just like it does for the sources statically configured in application.yml This is not happening either though.
So my question is whether the ConnectionSources API is intended for a different purpose than we are trying to use it for, or it is just not finished/tested yet.

Answer 1

I meant to come back to you. I did manage to figure out a solution. Now this is for schema per customer, not database per customer, but I suspect it would be easy to adapt. I first create the schema using a straight Groovy Sql object as follows:
void createAccountSchema(String tenantId) {
Sql sql = null
try {
sql = new Sql(dataSource as DataSource)
sql.withTransaction {
sql.execute("create schema ${tenantId}" as String)
}
} catch (Exception e) {
log.error("Unable to create schema for tenant $tenantId", e)
throw e
} finally {
sql?.close()
}
}
Then I run the same code as the Liquibase plugin uses, with some simple defaults, as follows:
void updateAccountSchema(String tenantId) {
def applicationContext = Holders.applicationContext
// Now try create the tables for the schema
try {
GrailsLiquibase gl = new GrailsLiquibase(applicationContext)
gl.dataSource = applicationContext.getBean("dataSource", DataSource)
gl.dropFirst = false
gl.changeLog = 'changelog-m.groovy'
gl.contexts = []
gl.labels = []
gl.defaultSchema = tenantId
gl.databaseChangeLogTableName = defaultChangelogTableName
gl.databaseChangeLogLockTableName = defaultChangelogLockTableName
gl.afterPropertiesSet() // this runs the update command
} catch (Exception e) {
log.error("Exception trying to create new account schema tables for $tenantId", e)
throw e
}
}
Finally, I tell Hibernate about the new schema as follows:
try {
hibernateDatastore.addTenantForSchema(tenantId)
} catch (Exception e) {
log.error("Exception adding tenant schema for ${tenantId}", e)
throw e
}
Anywhere you see me referring to 'hibernateDatastore' or 'dataSource' I have those injected by Grails as follows:
def hibernateDatastore
def dataSource
protected String defaultChangelogTableName = "databasechangelog"
protected String defaultChangelogLockTableName = "databasechangeloglock"
Hope this helps.