Descoped Devmode Plugin

About

The Devmode Maven Plugin enables redefinition of loaded classes at runtime. Its purpose is to allow the Descoped Container to be running whilst the developer can write code and (if possible) debug in real time. This is acheived by utilizing the Dynamic Code Evolution Virtual Machine (DCEVM) and the Hotswap Agent.

When invoking the devmode plugin at compile time it will automatically fork and configure a Java process that executes the mainClass defined.

This is useful when working with web development when aiming for rapid sketching and development.

Maven

Declare maven profile:

<profile>
    <id>dev</id>
    <build>
        <plugins>
            <plugin>
                <groupId>io.descoped.mojo</groupId>
                <artifactId>web-devmode-plugin</artifactId>
                <version>1.0.0-alpha5</version>
                <executions>
                    <execution>
                        <phase>compile</phase>
                        <goals>
                            <goal>run</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    ...
                </configuration>
            </plugin>
        </plugins>
    </build>
</profile>

Configuration options:

Option	Default	Description
outputDirectory	target/devmode	Work directory
webContent	N/A	Custom Web resources directory
mainClass	io.descoped.container.Main	Main class to be executed

Maven environment variables

Option	Description
updateHotswap	Force install process for the DCEVM Hotswap JVM
useJarInstaller	Use DCEVM Jar Installer instead of plugin installation
addTestClasses	Add `target/test-classes` to class path

Maven options are added as follows: mvn -D<option>

Use

Run in Devmode:

mvn clean compile -Pdev -DskipTests

Set up Idea

Plugin developer notes

Install plugin:

mvn clean install

Run test suite:

mvn clean test

To run the plugin in context of plugin source code:

mvn clean install -DskipTests -Pmojo

Release consideration

Before performing a new release, make sure to:

Update to the latest version (first entry of hotswapReleaseList) in MockHelper
Make sure to run all tests locally to ensure that the hotswap agent matches your JDK
Issue the test steps above first

Known limitations

This project has not been tested on Windows. Only Linux is supported and partially MacOS.
- The DCEVM on Mac for JDK8 doesn't work properly, because of build issues.
- Please refer to the Descoped DCEVM for Mac on Travis-CI for DCEVM on Mac
RelProxy and plain None mode not yet supported

Resources

Todo

Add addJavaArgument
Add addClassPathElement
Add an envvar 'descoped.hotswap=true' that can be used to identify if container is running in DCEVM mode

oranheim/descoped-devmode-plugin