如何在Datasource.groovy中获取服务器名称（如Tomcat、WebLogic）

Got it, let's figure out how to get server info in your Datasource.groovy file—since you can’t directly use getServletContext().getServerInfo() there like you do in controllers, we need to use early-available Java APIs instead. Here are practical approaches tailored to your needs:

Option 1: Get the Hostname of the Deployment Server #

If you need to distinguish between different physical/virtual servers (e.g., dev, test, prod hosts), use Java’s InetAddress class to fetch the server’s hostname directly:

import java.net.InetAddress

// Fetch the server hostname
def serverHostname = InetAddress.getLocalHost().getHostName()

// Use it to conditionally configure your datasource
environments {
    production {
        dataSource {
            if (serverHostname == "prod-db-primary") {
                url = "jdbc:mysql://primary-db:3306/app_db"
                username = "prod_user"
                password = "prod_pass"
            } else if (serverHostname == "prod-db-secondary") {
                url = "jdbc:mysql://secondary-db:3306/app_db"
                username = "prod_readonly_user"
                password = "prod_readonly_pass"
            }
            driverClassName = "com.mysql.cj.jdbc.Driver"
            dialect = org.hibernate.dialect.MySQL8Dialect
        }
    }
}

Note: Ensure your server’s /etc/hosts (or equivalent) is configured correctly—if not, getLocalHost() might return localhost instead of the actual hostname. For containerized environments (Docker/K8s), this might return the container ID, so consider passing a custom server identifier via environment variables instead:

// Fall back to hostname if env var isn't set
def serverIdentifier = System.getenv("SERVER_IDENTIFIER") ?: InetAddress.getLocalHost().getHostName()

Option 2: Detect the Application Server Type (Tomcat/Jetty, etc.) #

If you need to adjust logic based on which app server you’re running (e.g., Tomcat vs. Jetty), check system properties that each server exposes:

// Fetch server info system property (set by most app servers)
def serverInfo = System.getProperty("server.info")

// Check for specific server types
def isTomcat = serverInfo?.startsWith("Apache Tomcat")
def isJetty = serverInfo?.startsWith("Jetty")

// Apply server-specific datasource configs
if (isTomcat) {
    dataSource {
        // Tomcat-specific settings, like connection pool tweaks
        maxActive = 100
        maxIdle = 20
    }
} else if (isJetty) {
    dataSource {
        // Jetty-specific connection pool configs
        maxTotal = 100
        maxIdlePerKey = 20
    }
}

Other server-specific properties you can use:

• Tomcat: catalina.base or catalina.home
• Jetty: jetty.home
• WildFly: jboss.home.dir

Why getServletContext() Doesn’t Work Here #

Remember, Datasource.groovy loads very early in the Grails application lifecycle—way before the ServletContext is initialized. That’s why controller-level methods won’t work here; we have to rely on Java APIs that are available at JVM startup.

内容的提问来源于stack exchange，提问作者Ramesh