feat(install): the desktop app downloads from a link that never changes (#394)

`/download/windows` and `/download/linux` redirect to a one-minute
signed URL for the current desktop app (`desktop/<version>/` in the
releases bucket). `/desktop.sh` installs it on Linux for the calling
user, without sudo. The version handed out is a constant bumped by a
commit after each release. Tests: 180 pass.

apps/api/app/routes/install.ts

@@ -5,6 +5,8 @@ import { describeRoute } from 'hono-openapi';
 // The installer, embedded at build time so the script and the API that redeems
 // its token always ship as one version.
 import script from '../../install/install.sh' with { type: 'text' };
+import desktopScript from '../../install/desktop.sh' with { type: 'text' };
+import { DESKTOP_VERSION } from '../../install/desktop-version';
 import { presignGet } from '../utils/presign';
 
 /**
@@ -16,12 +18,37 @@ import { presignGet } from '../utils/presign';
  */
 export namespace InstallApi {
 	/** What may be downloaded: one component, versions and asset names by shape. */
-	const COMPONENTS = new Set(['host']);
+	const COMPONENTS = new Set(['host', 'desktop']);
 	const VERSION = /^\d+\.\d+\.\d+(-[0-9A-Za-z.]+)?$/;
 	const ASSET = /^[A-Za-z0-9][A-Za-z0-9._-]{0,127}$/;
 
 	const SIGNED_SECONDS = 60;
 
+	/** The desktop app's asset for each platform a person can download it for. */
+	const DESKTOP_ASSETS: Record<string, string> = {
+		windows: 'Nestri.exe',
+		linux: 'nestri-linux-x86_64'
+	};
+
+	function releases() {
+		const env = Env.get();
+		if (
+			!env.RELEASES_BUCKET ||
+			!env.RELEASES_ENDPOINT ||
+			!env.RELEASES_ACCESS_KEY_ID ||
+			!env.RELEASES_SECRET_ACCESS_KEY
+		) {
+			return null;
+		}
+		return {
+			endpoint: env.RELEASES_ENDPOINT,
+			bucket: env.RELEASES_BUCKET,
+			region: env.RELEASES_REGION,
+			accessKeyId: env.RELEASES_ACCESS_KEY_ID,
+			secretAccessKey: env.RELEASES_SECRET_ACCESS_KEY
+		};
+	}
+
 	export const route = new Hono()
 		.get(
 			'/install.sh',
@@ -55,26 +82,49 @@ export namespace InstallApi {
 				if (!COMPONENTS.has(component) || !VERSION.test(version) || !ASSET.test(asset)) {
 					return c.notFound();
 				}
-				const env = Env.get();
-				if (
-					!env.RELEASES_BUCKET ||
-					!env.RELEASES_ENDPOINT ||
-					!env.RELEASES_ACCESS_KEY_ID ||
-					!env.RELEASES_SECRET_ACCESS_KEY
-				) {
+				const bucket = releases();
+				if (!bucket) {
 					return c.json({ message: 'Downloads are not configured on this deployment.' }, 503);
 				}
-				const url = await presignGet(
-					{
-						endpoint: env.RELEASES_ENDPOINT,
-						bucket: env.RELEASES_BUCKET,
-						region: env.RELEASES_REGION,
-						accessKeyId: env.RELEASES_ACCESS_KEY_ID,
-						secretAccessKey: env.RELEASES_SECRET_ACCESS_KEY
-					},
-					`${component}/${version}/${asset}`,
-					SIGNED_SECONDS
-				);
+				const url = await presignGet(bucket, `${component}/${version}/${asset}`, SIGNED_SECONDS);
+				return c.redirect(url, 302);
+			}
+		)
+		.get(
+			'/desktop.sh',
+			describeRoute({
+				tags: ['Install'],
+				summary: 'The desktop app installer for Linux',
+				description:
+					'A POSIX shell script that installs the desktop app for the calling user, in ~/.local/bin with a launcher entry. Pipe it to `sh`.',
+				responses: { 200: { description: 'The script' } }
+			}),
+			(c) =>
+				c.body(desktopScript, 200, {
+					'content-type': 'text/x-shellscript; charset=utf-8',
+					'cache-control': 'no-cache'
+				})
+		)
+		.get(
+			'/download/:platform',
+			describeRoute({
+				tags: ['Install'],
+				summary: 'Download the desktop app',
+				description:
+					'Redirects to a short-lived signed URL for the current desktop app on `windows` or `linux`. This link does not change between versions.',
+				responses: {
+					302: { description: 'Where to download it' },
+					404: { description: 'Not available for that platform' }
+				}
+			}),
+			async (c) => {
+				const asset = DESKTOP_ASSETS[c.req.param('platform')];
+				if (!asset) return c.notFound();
+				const bucket = releases();
+				if (!bucket) {
+					return c.json({ message: 'Downloads are not configured on this deployment.' }, 503);
+				}
+				const url = await presignGet(bucket, `desktop/${DESKTOP_VERSION}/${asset}`, SIGNED_SECONDS);
 				return c.redirect(url, 302);
 			}
 		);

apps/api/install/desktop-version.ts

@@ -0,0 +1,6 @@
+/**
+ * The desktop app every download link hands out. Bumped by a commit once a
+ * release of that version is published, the same way the host installer's
+ * default is, so what a person downloads changes only through review.
+ */
+export const DESKTOP_VERSION = '0.1.0';

apps/api/install/desktop.sh

@@ -0,0 +1,36 @@
+#!/bin/sh
+# Installs the Nestri desktop app for the calling user: one binary in
+# ~/.local/bin and a launcher entry. No root, nothing outside $HOME.
+#
+#   curl -fsSL https://api.nestri.io/desktop.sh | sh
+set -eu
+
+API="${NESTRI_API:-https://api.nestri.io}"
+BIN="${XDG_BIN_HOME:-$HOME/.local/bin}"
+APPS="${XDG_DATA_HOME:-$HOME/.local/share}/applications"
+
+case "$(uname -s)-$(uname -m)" in
+	Linux-x86_64) ;;
+	*) echo "Nestri runs on x86_64 Linux and Windows for now." >&2; exit 1 ;;
+esac
+
+mkdir -p "$BIN" "$APPS"
+tmp="$BIN/.nestri.$$"
+trap 'rm -f "$tmp"' EXIT
+echo "Downloading Nestri..."
+curl -fSL --progress-bar "$API/download/linux" -o "$tmp"
+chmod 755 "$tmp"
+mv "$tmp" "$BIN/nestri"
+
+cat > "$APPS/nestri.desktop" <<DESKTOP
+[Desktop Entry]
+Type=Application
+Name=Nestri
+Comment=Play your games on our GPUs
+Exec=$BIN/nestri
+Terminal=false
+Categories=Game;
+DESKTOP
+
+echo "Installed. Open Nestri from your app launcher, or run: $BIN/nestri"
+case ":$PATH:" in *":$BIN:"*) ;; *) echo "($BIN is not on your PATH.)" ;; esac

apps/api/test/download.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, test } from 'bun:test';
+
+import { app } from '../app/index';
+
+describe('the desktop app download', () => {
+	test('the Linux installer is served as a script', async () => {
+		const res = await app.request('/desktop.sh');
+		expect(res.status).toBe(200);
+		expect(res.headers.get('content-type')).toContain('shellscript');
+		expect(await res.text()).toContain('/download/linux');
+	});
+
+	test('a platform that is not offered is not found', async () => {
+		expect((await app.request('/download/macos')).status).toBe(404);
+	});
+
+	test('a desktop asset is a known component', async () => {
+		// No bucket in tests: the route got past its allow-list to the config check.
+		const res = await app.request('/install/desktop/0.1.0/Nestri.exe');
+		expect([302, 503]).toContain(res.status);
+	});
+});