Why isn't --platform passed in to docker build in start / dev mode?

[zya]

Had an issue with docker layers in my SST container build, dug around and saw that in start mode, the --platform value is not passed in whereas in deploy mode, it is.

Why is that case? And can --platform be added to start mode as well.

v2/packages/sst/src/runtime/handlers/container.ts

Lines 250 to 355 in d6ba6fa

	if (input.mode === "start") {
	try {
	const result = await execAsync(
	[
	`docker build`,
	`-t sst-dev:${input.functionID}`,
	...(input.props.container?.file
	? [`-f ${input.props.container.file}`]
	: []),
	...Object.entries(input.props.container?.buildArgs || {}).map(
	([k, v]) => `--build-arg ${k}=${v}`
	),
	...(input.props.container?.buildSsh
	? [`--ssh ${input.props.container.buildSsh}`]
	: []),
	...(input.props.container?.cacheFrom || []).map(
	(v) =>
	"--cache-from=" +
	[
	`type=${v.type}`,
	...(v.params
	? Object.entries(v.params).map(
	([pk, pv]) => `${pk}=${pv}`
	)
	: []),
	].join(",")
	),
	...(input.props.container?.cacheTo
	? [
	"--cache-to=" +
	[
	`type=${input.props.container?.cacheTo.type}`,
	...(input.props.container?.cacheTo?.params
	? Object.entries(
	input.props.container?.cacheTo?.params
	).map(([pk, pv]) => `${pk}=${pv}`)
	: []
	)
	].join(","),,
	]
	: []),
	`.`,
	].join(" "),
	{
	cwd: project,
	env: {
	...process.env,
	},
	}
	);
	} catch (ex) {
	return {
	type: "error",
	errors: [String(ex)],
	};
	}
	}
	if (input.mode === "deploy") {
	try {
	const platform =
	input.props.architecture === "arm_64"
	? "linux/arm64"
	: "linux/amd64";
	await execAsync(
	[
	`docker build`,
	`-t sst-build:${input.functionID}`,
	...(input.props.container?.file
	? [`-f ${input.props.container.file}`]
	: []),
	...Object.entries(input.props.container?.buildArgs || {}).map(
	([k, v]) => `--build-arg ${k}=${v}`
	),
	...(input.props.container?.buildSsh
	? [`--ssh ${input.props.container.buildSsh}`]
	: []),
	...(input.props.container?.cacheFrom || []).map(
	(v) =>
	"--cache-from=" +
	[
	`type=${v.type}`,
	...(v.params
	? Object.entries(v.params).map(
	([pk, pv]) => `${pk}=${pv}`
	)
	: []),
	].join(",")
	),
	...(input.props.container?.cacheTo
	? [
	"--cache-to=" +
	[
	`type=${input.props.container?.cacheTo.type}`,
	...(input.props.container?.cacheTo?.params
	? Object.entries(
	input.props.container?.cacheTo?.params
	).map(([pk, pv]) => `${pk}=${pv}`)
	: []
	)
	].join(","),,
	]
	: []),
	`--platform ${platform}`,
	`.`,
	].join(" "),

[jayair]

Yeah feel free to open a PR

[zya]

@jayair so --platform wasn't intentionally left out in start mode?

[jayair]

I'm not entirely sure. It's likely that it wasn't initially supported.