Configuring grails datasources with username and password from OS environment - grails

Question

I am currently working on a grails application. Previously I have been using Django alot to create webapps. In django you can easily create settings that are collected from the OS environment. I find that to be an easy solution for making sure that you don't check in usernames and passwords into the source code repository.
So what I would like to do is in the DataSource.groovy be able to lift in the username and password from the OS environment. Has anyone done anything like this, or is this not the way to go forward?
If this is not the "grails way", how is it supposed to be done, because having the username and password in the repository just feels wrong?

Answer 1

You can write code in DataSource.groovy and Config.groovy to get env variable and then set username password and other things. I always to it for my production app, sample code is as follows
//Eample is based on url structure like "mysql://username:password#host/database?autoReconnect=true&useUnicode=yes&characterEncoding=UTF-8"
dataSource {
String mysqlUrl = System.getenv("DATABASE_URL")
println ">>>>>> Got DATABASE_URL: ${mysqlUrl} <<<<<<<"
URI dbUri = new URI(mysqlUrl);
username = dbUri.userInfo.split(":")[0]
password = dbUri.userInfo.split(":")[1]
String databaseUrl = "jdbc:${dbUri.scheme}://${dbUri.host}${dbUri.path}"
if (dbUri.port > 0) {
databaseUrl += ":${dbUri.port}"
}
String query = dbUri.query ?: "reconnect=true"
query += "&autoReconnect=true&useUnicode=yes&characterEncoding=UTF-8"
databaseUrl += "?${query}"
url = databaseUrl
dialect = 'org.hibernate.dialect.MySQL5InnoDBDialect'
}
This is one of the way I am sure there must be some simpler way to do this.
PS: I find it simple though :)

Answer 2

You can create a environment variable in Windows. Example DBCONNGRAILS. In config.groovy (...\grails-app\conf\config.groovy) you can use something like
def myConnectionString = System.getenv(DBCONNGRAILS)
WARNING: If you get variables from the environment(Windows) there will no problem when loading the value when in development. But when you are working with a production server, there will be cases when you will need to resart the OS for tomcat to be able to pick up the changes. I would recommend externalizing the config files.

Answer 3

You can externalized the configuration in any other place and load/merge it simply in your application configuration.

Answer 4

We use JNDI at work for exactly this scenario. We have context.xml files located within the individual server's Tomcat directories. The context.xml contains the datasource properties and then within the datasource closure (defined in Datasource.groovy), the jndiName property is set accordingly.
More Links about JNDI:
http://grails.github.io/grails-doc/2.3.7/guide/conf.html#JNDIDataSources
http://grails.asia/how-to-make-grails-use-jndi-datasource-with-tomcat