Add support for setting per-run environment variables

README.md

@@ -111,6 +111,12 @@ neoForge {
             ]
             systemProperty("a.b.c", "xyz")
         
+            // Set or add environment variables
+            environment = [
+                    "FOO_BAR": "123"
+            ]
+            environment("FOO_BAR", "123")
+        
             // Optionally set the log-level used by the game
             logLevel = org.slf4j.event.Level.DEBUG
         

src/main/java/net/neoforged/moddevgradle/dsl/RunModel.java

@@ -60,6 +60,12 @@ public String getName() {
 
     public abstract DirectoryProperty getGameDirectory();
 
+    public abstract MapProperty<String, String> getEnvironment();
+
+    public void environment(String key, String value) {
+        getEnvironment().put(key, value);
+    }
+
     public abstract MapProperty<String, String> getSystemProperties();
 
     public void systemProperty(String key, String value) {

src/main/java/net/neoforged/moddevgradle/internal/ModDevPlugin.java

@@ -313,6 +313,7 @@ public void apply(Project project) {
                 task.getClasspathProvider().from(sourceSet.getRuntimeClasspath());
                 task.getGameDirectory().set(run.getGameDirectory());
 
+                task.getEnvironmentProperty().set(run.getEnvironment());
                 task.jvmArgs(RunUtils.getArgFileParameter(prepareRunTask.get().getVmArgsFile().get()).replace("\\", "\\\\"));
                 task.getMainClass().set(RunUtils.DEV_LAUNCH_MAIN_CLASS);
                 task.args(RunUtils.getArgFileParameter(prepareRunTask.get().getProgramArgsFile().get()).replace("\\", "\\\\"));
@@ -645,6 +646,7 @@ private static void addIntelliJRunConfiguration(Project project,
         var sourceSets = ExtensionUtils.getExtension(project, "sourceSets", SourceSetContainer.class);
         appRun.setModuleRef(new ModuleRef(project, sourceSets.getByName("main")));
         appRun.setWorkingDirectory(run.getGameDirectory().get().getAsFile().getAbsolutePath());
+        appRun.setEnvs(run.getEnvironment().get());
 
         appRun.setJvmArgs(
                 RunUtils.escapeJvmArg(RunUtils.getArgFileParameter(prepareTask.getVmArgsFile().get()))
@@ -817,6 +819,7 @@ private static void addEclipseLaunchConfiguration(Project project,
                         RunUtils.escapeJvmArg(RunUtils.getIdeaModFoldersProvider(project, outputDirectory, run.getMods(), false).getArgument())
                 )
                 .args(RunUtils.escapeJvmArg(RunUtils.getArgFileParameter(prepareTask.getProgramArgsFile().get())))
+                .envVar(run.getEnvironment().get())
                 .workingDirectory(run.getGameDirectory().get().getAsFile().getAbsolutePath())
                 .jreContainer("JavaSE-21") // TODO
                 .build(RunUtils.DEV_LAUNCH_MAIN_CLASS);

src/main/java/net/neoforged/moddevgradle/internal/RunGameTask.java

@@ -2,7 +2,9 @@
 
 import org.gradle.api.file.ConfigurableFileCollection;
 import org.gradle.api.file.DirectoryProperty;
+import org.gradle.api.provider.MapProperty;
 import org.gradle.api.tasks.Classpath;
+import org.gradle.api.tasks.Input;
 import org.gradle.api.tasks.InputFiles;
 import org.gradle.api.tasks.Internal;
 import org.gradle.api.tasks.JavaExec;
@@ -13,6 +15,7 @@
 import java.io.IOException;
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
+import java.util.HashMap;
 
 /**
  * By extending JavaExec, we allow IntelliJ to automatically attach a debugger to the forked JVM, making
@@ -24,6 +27,9 @@ public abstract class RunGameTask extends JavaExec {
     @InputFiles
     public abstract ConfigurableFileCollection getClasspathProvider();
 
+    @Input
+    public abstract MapProperty<String, String> getEnvironmentProperty();
+
     @Internal
     public abstract DirectoryProperty getGameDirectory();
 
@@ -41,6 +47,8 @@ public void exec() {
             throw new UncheckedIOException("Failed to create run directory", e);
         }
 
+        getEnvironment().putAll(getEnvironmentProperty().get());
+
         classpath(getClasspathProvider());
         setWorkingDir(runDir);
         super.exec();

testproject/build.gradle

@@ -32,6 +32,7 @@ neoForge {
         }
         server {
             server()
+            environment("BLAH_BLUBB", "123");
         }
     }