Per Environment Configuration
Grails supports the concept of per environment configuration. Both the
Config.groovy
file and the
DataSource.groovy
file within the
grails-app/conf
directory can take advantage of per environment configuration using the syntax provided by
ConfigSlurper As an example consider the following default
DataSource
definition provided by Grails:
dataSource {
pooled = false
driverClassName = "org.hsqldb.jdbcDriver"
username = "sa"
password = ""
}
environments {
development {
dataSource {
dbCreate = "create-drop" // one of 'create', 'createeate-drop','update'
url = "jdbc:hsqldb:mem:devDB"
}
}
test {
dataSource {
dbCreate = "update"
url = "jdbc:hsqldb:mem:testDb"
}
}
production {
dataSource {
dbCreate = "update"
url = "jdbc:hsqldb:file:prodDb;shutdown=true"
}
}
}
Notice how the common configuration is provided at the top level and then an
environments
block specifies per environment settings for the
dbCreate
and
url
properties of the
DataSource
. This syntax can also be used within
Config.groovy
.
Packaging and Running for Different Environments
Grails'
command line has built in capabilities to execute any command within the context of a specific environment. The format is:
grails [environment] [command name]
In addition, there are 3 preset environments known to Grails:
dev
,
prod
, and
test
for
development
,
production
and
test
. For example to create a WAR for the
test
environment you could do:
If you have other environments that you need to target you can pass a
grails.env
variable to any command:
grails -Dgrails.env=UAT run-app
Programmatic Environment Detection
Within your code, such as in a Gant script or a bootstrap class you can detect the environment using the
Environment class:
import grails.util.Environment...switch(Environment.current) {
case Environment.DEVELOPMENT:
configureForDevelopment()
break
case Environment.PRODUCTION:
configureForProduction()
break
}
Per Environment Bootstrapping
Its often desirable to run code when your application starts up on a per-environment basis. To do so you can use the
grails-app/conf/BootStrap.groovy
file's support for per-environment execution:
def init = { ServletContext ctx ->
environments {
production {
ctx.setAttribute("env", "prod")
}
development {
ctx.setAttribute("env", "dev")
}
}
ctx.setAttribute("foo", "bar")
}
Generic Per Environment Execution
The previous
BootStrap
example uses the
grails.util.Environment
class internally to execute. You can also use this class yourself to execute your own environment specific logic:
Environment.executeForCurrentEnvironment {
production {
// do something in production
}
development {
// do something only in development
}
}