Bug fix: Merge metadata logic for containerEnv - devcontainer build

src/spec-node/containerFeatures.ts

@@ -285,7 +285,7 @@ async function getFeaturesBuildOptions(params: DockerResolverParameters, devCont
 	// When copying via buildkit, the content is accessed via '.' (i.e. in the context root)
 	// When copying via temp image, the content is in '/tmp/build-features'
 	const contentSourceRootPath = useBuildKitBuildContexts ? '.' : '/tmp/build-features/';
-	const dockerfile = getContainerFeaturesBaseDockerFile()
+	let dockerfile = getContainerFeaturesBaseDockerFile()
 		.replace('#{nonBuildKitFeatureContentFallback}', useBuildKitBuildContexts ? '' : `FROM ${buildContentImageName} as dev_containers_feature_content_source`)
 		.replace('{contentSourceRootPath}', contentSourceRootPath)
 		.replace('#{featureBuildStages}', getFeatureBuildStages(featuresConfig, buildStageScripts, contentSourceRootPath))
@@ -294,6 +294,14 @@ async function getFeaturesBuildOptions(params: DockerResolverParameters, devCont
 		.replace('#{copyFeatureBuildStages}', getCopyFeatureBuildStages(featuresConfig, buildStageScripts))
 		.replace('#{devcontainerMetadata}', getDevcontainerMetadataLabel(imageMetadata, common.experimentalImageMetadata))
 		;
+
+	const rawContainerEnv = imageMetadata.raw.find(entry => entry.containerEnv)?.containerEnv;
+	if (rawContainerEnv !== undefined) {
+		let keys = Object.keys(rawContainerEnv);
+		const concatenatedEnv = keys.map(k => `ENV ${k}=${rawContainerEnv![k]}`).join('\n');
+		dockerfile += concatenatedEnv;
+	}
+
 	const syntax = imageBuildInfo.dockerfile?.preamble.directives.syntax;
 	const dockerfilePrefixContent = `${useBuildKitBuildContexts && !(imageBuildInfo.dockerfile && supportsBuildContexts(imageBuildInfo.dockerfile)) ?
 		'# syntax=docker/dockerfile:1.4' :

src/test/cli.build.test.ts

@@ -222,5 +222,20 @@ describe('Dev Containers CLI', function () {
 				await shellExec(`docker buildx rm ${builderName}`);
 			}
 		});
+
+		it('should follow the correct merge logic for containerEnv', async () => {
+			const res = await shellExec(`${cli} build --workspace-folder ${__dirname}/configs/image-metadata-containerEnv --image-name "test-metadata"`);
+			const response = JSON.parse(res.stdout);
+			assert.equal(response.outcome, 'success');
+
+			const resRun = await shellExec(`docker run -it -d "test-metadata"`);
+			const containerId: string = resRun.stdout.split('\n')[0];
+			assert.ok(containerId, 'Container id not found.');
+
+			const result = await shellExec(`docker exec ${containerId} bash -c 'echo $JAVA_HOME'`);
+			assert.equal('/usr/lib/jvm/msopenjdk-current\n', result.stdout);
+
+			await shellExec(`docker rm -f ${containerId}`);
+		});
 	});
 });

src/test/cli.up.test.ts

@@ -165,5 +165,18 @@ describe('Dev Containers CLI', function () {
 				});
 			});
 		});
+
+		it('should follow the correct merge logic for containerEnv', async () => {
+			const res = await shellExec(`${cli} up --workspace-folder ${__dirname}/configs/image-metadata-containerEnv`);
+			const response = JSON.parse(res.stdout);
+			assert.equal(response.outcome, 'success');
+			const containerId: string = response.containerId;
+			assert.ok(containerId, 'Container id not found.');
+
+			const result = await shellExec(`docker exec ${containerId} bash -c 'echo $JAVA_HOME'`);
+			assert.equal('/usr/lib/jvm/msopenjdk-current\n', result.stdout);
+
+			await shellExec(`docker rm -f ${containerId}`);
+		});
 	});
 });

src/test/configs/image-metadata-containerEnv/.devcontainer/devcontainer.json

@@ -0,0 +1,11 @@
+{
+    "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+    "features": {
+        "ghcr.io/devcontainers/features/java:1": {
+            "version": "none"
+        }
+    },
+    "containerEnv": {
+        "JAVA_HOME": "/usr/lib/jvm/msopenjdk-current"
+    }
+}