Inline buildx global build and target platform envvars when resolving base image and user (#1169)

trxcllnt · web-flow · commit 217ae9c97b0c · 2026-03-17T10:41:42.000+01:00
diff --git a/src/spec-node/configContainer.ts b/src/spec-node/configContainer.ts
@@ -60,7 +60,7 @@ async function resolveWithLocalFolder(params: DockerResolverParameters, parsedAu
 
 	const { dockerCLI, dockerComposeCLI } = params;
 	const { env } = common;
-	const cliParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env, output, platformInfo: params.platformInfo };
+	const cliParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env, output, buildPlatformInfo: params.buildPlatformInfo, targetPlatformInfo: params.targetPlatformInfo };
 	await ensureNoDisallowedFeatures(cliParams, config, additionalFeatures, idLabels);
 
 	await runInitializeCommand({ ...params, common: { ...common, output: common.lifecycleHook.output } }, config.initializeCommand, common.lifecycleHook.onDidInput);
diff --git a/src/spec-node/devContainers.ts b/src/spec-node/devContainers.ts
@@ -172,7 +172,12 @@ export async function createDockerParams(options: ProvisionOptions, disposables:
 		output: common.output,
 	}, dockerPath, dockerComposePath);
 
-	const platformInfo = (() => {
+	const buildPlatformInfo = {
+		os: mapNodeOSToGOOS(cliHost.platform),
+		arch: mapNodeArchitectureToGOARCH(cliHost.arch),
+	};
+
+	const targetPlatformInfo = (() => {
 		if (common.buildxPlatform) {
 			const slash1 = common.buildxPlatform.indexOf('/');
 			const slash2 = common.buildxPlatform.indexOf('/', slash1 + 1);
@@ -204,7 +209,8 @@ export async function createDockerParams(options: ProvisionOptions, disposables:
 		dockerComposeCLI,
 		env: cliHost.env,
 		output,
-		platformInfo
+		buildPlatformInfo,
+		targetPlatformInfo
 	}));
 
 	const dockerEngineVer = await dockerEngineVersion({
@@ -213,7 +219,8 @@ export async function createDockerParams(options: ProvisionOptions, disposables:
 		dockerComposeCLI,
 		env: cliHost.env,
 		output,
-		platformInfo
+		buildPlatformInfo,
+		targetPlatformInfo
 	});	
 
 	return {
@@ -246,7 +253,8 @@ export async function createDockerParams(options: ProvisionOptions, disposables:
 		additionalLabels: options.additionalLabels,
 		buildxOutput: common.buildxOutput,
 		buildxCacheTo: common.buildxCacheTo,
-		platformInfo
+		buildPlatformInfo,
+		targetPlatformInfo
 	};
 }
 
diff --git a/src/spec-node/devContainersSpecCLI.ts b/src/spec-node/devContainersSpecCLI.ts
@@ -641,7 +641,7 @@ async function doBuild({
 			throw new ContainerError({ description: '--push true cannot be used with --output.' });
 		}
 
-		const buildParams: DockerCLIParameters = { cliHost, dockerCLI: params.dockerCLI, dockerComposeCLI, env, output, platformInfo: params.platformInfo };
+		const buildParams: DockerCLIParameters = { cliHost, dockerCLI: params.dockerCLI, dockerComposeCLI, env, output, buildPlatformInfo: params.buildPlatformInfo, targetPlatformInfo: params.targetPlatformInfo };
 		await ensureNoDisallowedFeatures(buildParams, config, additionalFeatures, undefined);
 
 		// Support multiple use of `--image-name`
@@ -1058,16 +1058,18 @@ async function readConfiguration({
 			env: cliHost.env,
 			output,
 		}, dockerCLI, dockerComposePath || 'docker-compose');
+		const buildPlatformInfo = {
+			os: mapNodeOSToGOOS(cliHost.platform),
+			arch: mapNodeArchitectureToGOARCH(cliHost.arch),
+		};
 		const params: DockerCLIParameters = {
 			cliHost,
 			dockerCLI,
 			dockerComposeCLI,
 			env: cliHost.env,
 			output,
-			platformInfo: {
-				os: mapNodeOSToGOOS(cliHost.platform),
-				arch: mapNodeArchitectureToGOARCH(cliHost.arch),
-			}
+			buildPlatformInfo,
+			targetPlatformInfo: buildPlatformInfo
 		};
 		const { container, idLabels } = await findContainerAndIdLabels(params, containerId, providedIdLabels, workspaceFolder, configPath?.fsPath);
 		if (container) {
diff --git a/src/spec-node/dockerCompose.ts b/src/spec-node/dockerCompose.ts
@@ -27,7 +27,7 @@ const serviceLabel = 'com.docker.compose.service';
 export async function openDockerComposeDevContainer(params: DockerResolverParameters, workspace: Workspace, config: SubstitutedConfig<DevContainerFromDockerComposeConfig>, idLabels: string[], additionalFeatures: Record<string, string | boolean | Record<string, string | boolean>>): Promise<ResolverResult> {
 	const { common, dockerCLI, dockerComposeCLI } = params;
 	const { cliHost, env, output } = common;
-	const buildParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env, output, platformInfo: params.platformInfo };
+	const buildParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env, output, buildPlatformInfo: params.buildPlatformInfo, targetPlatformInfo: params.targetPlatformInfo };
 	return _openDockerComposeDevContainer(params, buildParams, workspace, config, getRemoteWorkspaceFolder(config.config), idLabels, additionalFeatures);
 }
 
@@ -155,7 +155,7 @@ export async function buildAndExtendDockerCompose(configWithRaw: SubstitutedConf
 	const { cliHost, env, output } = common;
 	const { config } = configWithRaw;
 
-	const cliParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI: dockerComposeCLIFunc, env, output, platformInfo: params.platformInfo };
+	const cliParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI: dockerComposeCLIFunc, env, output, buildPlatformInfo: params.buildPlatformInfo, targetPlatformInfo: params.targetPlatformInfo };
 	const composeConfig = await readDockerComposeConfig(cliParams, localComposeFiles, envFile);
 	const composeService = composeConfig.services[config.service];
 
diff --git a/src/spec-node/dockerfileUtils.ts b/src/spec-node/dockerfileUtils.ts
@@ -81,7 +81,7 @@ export function extractDockerfile(dockerfile: string): Dockerfile {
 	} as Dockerfile;
 }
 
-export function findUserStatement(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, target: string | undefined) {
+export function findUserStatement(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, target: string | undefined) {
 	let stage: Stage | undefined = target ? dockerfile.stagesByLabel[target] : dockerfile.stages[dockerfile.stages.length - 1];
 	const seen = new Set<Stage>();
 	while (stage) {
@@ -92,15 +92,15 @@ export function findUserStatement(dockerfile: Dockerfile, buildArgs: Record<stri
 
 		const i = findLastIndex(stage.instructions, i => i.instruction === 'USER');
 		if (i !== -1) {
-			return replaceVariables(dockerfile, buildArgs, baseImageEnv, stage.instructions[i].name, stage, i) || undefined;
+			return replaceVariables(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, stage.instructions[i].name, stage, i) || undefined;
 		}
-		const image = replaceVariables(dockerfile, buildArgs, baseImageEnv, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
+		const image = replaceVariables(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
 		stage = dockerfile.stagesByLabel[image];
 	}
 	return undefined;
 }
 
-export function findBaseImage(dockerfile: Dockerfile, buildArgs: Record<string, string>, target: string | undefined) {
+export function findBaseImage(dockerfile: Dockerfile, buildArgs: Record<string, string>, target: string | undefined, globalBuildxPlatformArgs: Record<string, string> = {}) {
 	let stage: Stage | undefined = target ? dockerfile.stagesByLabel[target] : dockerfile.stages[dockerfile.stages.length - 1];
 	const seen = new Set<Stage>();
 	while (stage) {
@@ -109,7 +109,7 @@ export function findBaseImage(dockerfile: Dockerfile, buildArgs: Record<string,
 		}
 		seen.add(stage);
 
-		const image = replaceVariables(dockerfile, buildArgs, /* not available in FROM instruction */ {}, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
+		const image = replaceVariables(dockerfile, buildArgs, /* not available in FROM instruction */ {}, globalBuildxPlatformArgs, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
 		const nextStage = dockerfile.stagesByLabel[image];
 		if (!nextStage) {
 			return image;
@@ -155,12 +155,12 @@ function getExpressionValue(option: string, isSet: boolean, word: string, value:
 	return operations[option](isSet, word, value).replace(/^['"]|['"]$/g, ''); // remove quotes from start and end of the string
 }
 
-function replaceVariables(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, str: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number) {			
+function replaceVariables(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, str: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number) {			
 	return [...str.matchAll(argumentExpression)]
 		.map(match => {
 			const variable = match.groups!.variable;
 			const isVarExp = match.groups!.isVarExp ? true : false;
-			let value = findValue(dockerfile, buildArgs, baseImageEnv, variable, stage, beforeInstructionIndex) || '';
+			let value = findValue(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, variable, stage, beforeInstructionIndex) || '';
 			if (isVarExp) {
 				// Handle replacing variable expressions (${var:+word}) if they exist
 				const option = match.groups!.option;
@@ -178,7 +178,7 @@ function replaceVariables(dockerfile: Dockerfile, buildArgs: Record<string, stri
 		.reduce((str, { begin, end, value }) => str.substring(0, begin) + value + str.substring(end), str);
 }
 
-function findValue(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, variable: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number): string | undefined {
+function findValue(dockerfile: Dockerfile, buildArgs: Record<string, string>, baseImageEnv: Record<string, string>, globalBuildxPlatformArgs: Record<string, string> = {}, variable: string, stage: { from?: From; instructions: Instruction[] }, beforeInstructionIndex: number): string | undefined {
 	let considerArg = true;
 	const seen = new Set<typeof stage>();
 	while (true) {
@@ -191,22 +191,22 @@ function findValue(dockerfile: Dockerfile, buildArgs: Record<string, string>, ba
 		if (i !== -1) {
 			const instruction = stage.instructions[i];
 			if (instruction.instruction === 'ENV') {
-				return replaceVariables(dockerfile, buildArgs, baseImageEnv, instruction.value!, stage, i);
+				return replaceVariables(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, instruction.value!, stage, i);
 			}
 			if (instruction.instruction === 'ARG') {
-				return replaceVariables(dockerfile, buildArgs, baseImageEnv, buildArgs[instruction.name] ?? instruction.value, stage, i);
+				return replaceVariables(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, buildArgs[instruction.name] ?? instruction.value, stage, i);
 			}
 		}
 
 		if (!stage.from) {
-			const value = baseImageEnv[variable];
+			const value = baseImageEnv[variable] ?? globalBuildxPlatformArgs[variable];
 			if (typeof value === 'string') {
 				return value;
 			}
 			return undefined;
 		}
 
-		const image = replaceVariables(dockerfile, buildArgs, baseImageEnv, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
+		const image = replaceVariables(dockerfile, buildArgs, baseImageEnv, globalBuildxPlatformArgs, stage.from.image, dockerfile.preamble, dockerfile.preamble.instructions.length);
 		stage = dockerfile.stagesByLabel[image] || dockerfile.preamble;
 		beforeInstructionIndex = stage.instructions.length;
 		considerArg = stage === dockerfile.preamble;
diff --git a/src/spec-node/imageMetadata.ts b/src/spec-node/imageMetadata.ts
@@ -4,6 +4,7 @@
  *--------------------------------------------------------------------------------------------*/
 
 import { ContainerError } from '../spec-common/errors';
+import { PlatformInfo } from '../spec-common/commonUtils';
 import { LifecycleCommand, LifecycleHooksInstallMap } from '../spec-common/injectHeadless';
 import { DevContainerConfig, DevContainerConfigCommand, DevContainerFromDockerComposeConfig, DevContainerFromDockerfileConfig, DevContainerFromImageConfig, getDockerComposeFilePaths, getDockerfilePath, HostGPURequirements, HostRequirements, isDockerFileConfig, PortAttributes, UserEnvProbe } from '../spec-configuration/configuration';
 import { Feature, FeaturesConfig, Mount, parseMount, SchemaFeatureLifecycleHooks } from '../spec-configuration/containerFeaturesConfiguration';
@@ -349,7 +350,7 @@ export async function getImageBuildInfo(params: DockerResolverParameters | Docke
 		const cwdEnvFile = cliHost.path.join(cliHost.cwd, '.env');
 		const envFile = Array.isArray(config.dockerComposeFile) && config.dockerComposeFile.length === 0 && await cliHost.isFile(cwdEnvFile) ? cwdEnvFile : undefined;
 		const composeFiles = await getDockerComposeFilePaths(cliHost, config, cliHost.env, cliHost.cwd);
-		const buildParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env: cliHost.env, output, platformInfo: params.platformInfo };
+		const buildParams: DockerCLIParameters = { cliHost, dockerCLI, dockerComposeCLI, env: cliHost.env, output, buildPlatformInfo: params.buildPlatformInfo, targetPlatformInfo: params.targetPlatformInfo };
 
 		const composeConfig = await readDockerComposeConfig(buildParams, composeFiles, envFile);
 		const services = Object.keys(composeConfig.services || {});
@@ -394,18 +395,37 @@ export async function getImageBuildInfoFromImage(params: DockerResolverParameter
 export async function getImageBuildInfoFromDockerfile(params: DockerResolverParameters | DockerCLIParameters, dockerfile: string, dockerBuildArgs: Record<string, string>, targetStage: string | undefined, substitute: SubstituteConfig) {
 	const { output } = 'output' in params ? params : params.common;
 	const omitSyntaxDirective = 'common' in params ? !!params.common.omitSyntaxDirective : false;
-	return internalGetImageBuildInfoFromDockerfile(imageName => inspectDockerImage(params, imageName, true), dockerfile, dockerBuildArgs, targetStage, substitute, output, omitSyntaxDirective);
+	return internalGetImageBuildInfoFromDockerfile(imageName => inspectDockerImage(params, imageName, true), dockerfile, dockerBuildArgs, targetStage, substitute, output, omitSyntaxDirective, params.buildPlatformInfo, params.targetPlatformInfo);
 }
 
-export async function internalGetImageBuildInfoFromDockerfile(inspectDockerImage: (imageName: string) => Promise<ImageDetails>, dockerfileText: string, dockerBuildArgs: Record<string, string>, targetStage: string | undefined, substitute: SubstituteConfig, output: Log, omitSyntaxDirective: boolean): Promise<ImageBuildInfo> {
+export async function internalGetImageBuildInfoFromDockerfile(inspectDockerImage: (imageName: string) => Promise<ImageDetails>, dockerfileText: string, dockerBuildArgs: Record<string, string>, targetStage: string | undefined, substitute: SubstituteConfig, output: Log, omitSyntaxDirective: boolean, buildPlatform: PlatformInfo, targetPlatform: PlatformInfo): Promise<ImageBuildInfo> {
 	const dockerfile = extractDockerfile(dockerfileText);
 	if (dockerfile.preamble.directives.syntax && omitSyntaxDirective) {
 		output.write(`Omitting syntax directive '${dockerfile.preamble.directives.syntax}' from Dockerfile.`, LogLevel.Trace);
 		delete dockerfile.preamble.directives.syntax;
 	}
-	const baseImage = findBaseImage(dockerfile, dockerBuildArgs, targetStage);
+	// https://github.com/moby/buildkit/blob/master/frontend/dockerfile/docs/reference.md#automatic-platform-args-in-the-global-scope
+	const globalBuildxPlatformArgs = {
+		// platform of the node performing the build.
+		BUILDPLATFORM: [buildPlatform.os, buildPlatform.arch, buildPlatform.variant].filter(Boolean).join("/"),
+		// OS component of BUILDPLATFORM
+		BUILDOS: buildPlatform.os,
+		// architecture component of BUILDPLATFORM
+		BUILDARCH: buildPlatform.arch,
+		// variant component of BUILDPLATFORM
+		BUILDVARIANT: buildPlatform.variant ?? "",
+		// platform of the build result. Eg linux/amd64, linux/arm/v7, windows/amd64.
+		TARGETPLATFORM: [targetPlatform.os, targetPlatform.arch, targetPlatform.variant].filter(Boolean).join("/"),
+		// OS component of TARGETPLATFORM
+		TARGETOS: targetPlatform.os,
+		// architecture component of TARGETPLATFORM
+		TARGETARCH: targetPlatform.arch,
+		// variant component of TARGETPLATFORM
+		TARGETVARIANT: targetPlatform.variant ?? "",
+	};
+	const baseImage = findBaseImage(dockerfile, dockerBuildArgs, targetStage, globalBuildxPlatformArgs);
 	const imageDetails = baseImage && await inspectDockerImage(baseImage) || undefined;
-	const dockerfileUser = findUserStatement(dockerfile, dockerBuildArgs, envListToObj(imageDetails?.Config.Env), targetStage);
+	const dockerfileUser = findUserStatement(dockerfile, dockerBuildArgs, envListToObj(imageDetails?.Config.Env), globalBuildxPlatformArgs, targetStage);
 	const user = dockerfileUser || imageDetails?.Config.User || 'root';
 	const metadata = imageDetails ? getImageMetadata(imageDetails, substitute, output) : { config: [], raw: [], substitute };
 	return {
diff --git a/src/spec-node/upgradeCommand.ts b/src/spec-node/upgradeCommand.ts
@@ -86,16 +86,18 @@ async function featuresUpgrade({
 			env: cliHost.env,
 			output,
 		}, dockerPath, dockerComposePath);
+		const buildPlatformInfo = {
+			os: mapNodeOSToGOOS(cliHost.platform),
+			arch: mapNodeArchitectureToGOARCH(cliHost.arch),
+		};
 		const dockerParams: DockerCLIParameters = {
 			cliHost,
 			dockerCLI: dockerPath,
 			dockerComposeCLI,
 			env: cliHost.env,
 			output,
-			platformInfo: {
-				os: mapNodeOSToGOOS(cliHost.platform),
-				arch: mapNodeArchitectureToGOARCH(cliHost.arch),
-			}
+			buildPlatformInfo,
+			targetPlatformInfo: buildPlatformInfo,
 		};
 
 		const workspace = workspaceFromPath(cliHost.path, workspaceFolder);
diff --git a/src/spec-node/utils.ts b/src/spec-node/utils.ts
@@ -134,7 +134,8 @@ export interface DockerResolverParameters {
 	additionalLabels: string[];
 	buildxOutput: string | undefined;
 	buildxCacheTo: string | undefined;
-	platformInfo: PlatformInfo;
+	buildPlatformInfo: PlatformInfo;
+	targetPlatformInfo: PlatformInfo;
 }
 
 export interface ResolverResult {
@@ -250,7 +251,7 @@ export async function inspectDockerImage(params: DockerResolverParameters | Dock
 			throw inspectErr;
 		}
 		try {
-			return await inspectImageInRegistry(output, params.platformInfo, imageName);
+			return await inspectImageInRegistry(output, params.targetPlatformInfo, imageName);
 		} catch (inspectErr2) {
 			output.write(`Error fetching image details: ${inspectErr2?.message}`, LogLevel.Info);
 		}
diff --git a/src/spec-shutdown/dockerUtils.ts b/src/spec-shutdown/dockerUtils.ts
@@ -52,7 +52,8 @@ export interface DockerCLIParameters {
 	dockerComposeCLI: () => Promise<DockerComposeCLI>;
 	env: NodeJS.ProcessEnv;
 	output: Log;
-	platformInfo: PlatformInfo;
+	buildPlatformInfo: PlatformInfo;
+	targetPlatformInfo: PlatformInfo;
 }
 
 export interface PartialExecParameters {
diff --git a/src/test/dockerfileUtils.test.ts b/src/test/dockerfileUtils.test.ts
diff --git a/src/test/testUtils.ts b/src/test/testUtils.ts

Original file line number	Diff line number	Diff line change
`@@ -134,7 +134,8 @@ export interface DockerResolverParameters {`
`134`	`134`	`additionalLabels: string[];`
`135`	`135`	`buildxOutput: string \| undefined;`
`136`	`136`	`buildxCacheTo: string \| undefined;`
`137`		`- platformInfo: PlatformInfo;`
	`137`	`+ buildPlatformInfo: PlatformInfo;`
	`138`	`+ targetPlatformInfo: PlatformInfo;`
`138`	`139`	`}`
`139`	`140`
`140`	`141`	`export interface ResolverResult {`
`@@ -250,7 +251,7 @@ export async function inspectDockerImage(params: DockerResolverParameters \| Dock`
`250`	`251`	`throw inspectErr;`
`251`	`252`	`}`
`252`	`253`	`try {`
`253`		`- return await inspectImageInRegistry(output, params.platformInfo, imageName);`
	`254`	`+ return await inspectImageInRegistry(output, params.targetPlatformInfo, imageName);`
`254`	`255`	`} catch (inspectErr2) {`
`255`	`256`	output.write(`Error fetching image details: ${inspectErr2?.message}`, LogLevel.Info);
`256`	`257`	`}`
Original file line number	Diff line number	Diff line change
`@@ -52,7 +52,8 @@ export interface DockerCLIParameters {`
`52`	`52`	`dockerComposeCLI: () => Promise<DockerComposeCLI>;`
`53`	`53`	`env: NodeJS.ProcessEnv;`
`54`	`54`	`output: Log;`
`55`		`- platformInfo: PlatformInfo;`
	`55`	`+ buildPlatformInfo: PlatformInfo;`
	`56`	`+ targetPlatformInfo: PlatformInfo;`
`56`	`57`	`}`
`57`	`58`
`58`	`59`	`export interface PartialExecParameters {`