Add config file support and update default ports

src/cli.ts

@@ -1,8 +1,10 @@
 #!/usr/bin/env node
+import { existsSync } from "node:fs";
 import { mkdir, rm, writeFile } from "node:fs/promises";
 import { homedir } from "node:os";
-import { join } from "node:path";
+import { dirname, join, resolve } from "node:path";
 import { spawnSync } from "node:child_process";
+import { defaultPiWebConfigPath, examplePiWebConfig } from "./config.js";
 
 const serviceDir = join(homedir(), ".config", "systemd", "user");
 const sessiondServiceName = "pi-web-sessiond.service";
@@ -11,6 +13,7 @@ const webServiceName = "pi-web.service";
 interface InstallOptions {
   host: string;
   port: string;
+  config?: string;
 }
 
 function run(command: string, args: string[], options: { check?: boolean } = {}): number {
@@ -30,7 +33,7 @@ function hasCommand(command: string): boolean {
 }
 
 function parseInstallOptions(args: string[]): InstallOptions {
-  const options: InstallOptions = { host: "127.0.0.1", port: "3000" };
+  const options: InstallOptions = { host: "127.0.0.1", port: "8504" };
   for (let i = 0; i < args.length; i += 1) {
     const arg = args[i];
     if (arg === undefined) continue;
@@ -48,6 +51,13 @@ function parseInstallOptions(args: string[]): InstallOptions {
       i += 1;
     } else if (arg.startsWith("--port=")) {
       options.port = arg.slice("--port=".length);
+    } else if (arg === "--config") {
+      const value = args[i + 1];
+      if (value === undefined) throw new Error("--config requires a value");
+      options.config = value;
+      i += 1;
+    } else if (arg.startsWith("--config=")) {
+      options.config = arg.slice("--config=".length);
     } else if (arg === "--user-systemd") {
       // Accepted for readability; user systemd is the only installer target for now.
     } else {
@@ -81,6 +91,7 @@ WantedBy=default.target
 }
 
 function webUnit(options: InstallOptions): string {
+  const configEnvironment = options.config === undefined ? "" : `Environment="PI_WEB_CONFIG=${systemdEscape(resolve(options.config))}"\n`;
   return `[Unit]
 Description=Pi Web server
 After=${sessiondServiceName}
@@ -88,9 +99,7 @@ Wants=${sessiondServiceName}
 
 [Service]
 Type=simple
-Environment="PI_WEB_HOST=${systemdEscape(options.host)}"
-Environment="PI_WEB_PORT=${systemdEscape(options.port)}"
-ExecStart=/usr/bin/env bash -lc ${shellSingleQuote("exec pi-web-server")}
+${configEnvironment}ExecStart=/usr/bin/env bash -lc ${shellSingleQuote("exec pi-web-server")}
 Restart=on-failure
 RestartSec=2
 
@@ -99,12 +108,23 @@ WantedBy=default.target
 `;
 }
 
+async function writeInitialConfig(options: InstallOptions): Promise<string> {
+  const configPath = options.config === undefined ? defaultPiWebConfigPath() : resolve(options.config);
+  await mkdir(dirname(configPath), { recursive: true });
+  if (!existsSync(configPath)) {
+    await writeFile(configPath, examplePiWebConfig({ host: options.host, port: Number(options.port) }));
+  }
+  return configPath;
+}
+
 async function install(args: string[]): Promise<void> {
   const options = parseInstallOptions(args);
   if (!hasCommand("systemctl")) throw new Error("systemctl was not found in a bash login shell");
   if (!hasCommand("pi-web-server")) throw new Error("pi-web-server was not found in a bash login shell. Is pi-web installed globally?");
   if (!hasCommand("pi-web-sessiond")) throw new Error("pi-web-sessiond was not found in a bash login shell. Is pi-web installed globally?");
 
+  const configPath = await writeInitialConfig(options);
+
   await mkdir(serviceDir, { recursive: true });
   await writeFile(join(serviceDir, sessiondServiceName), sessiondUnit());
   await writeFile(join(serviceDir, webServiceName), webUnit(options));
@@ -114,6 +134,7 @@ async function install(args: string[]): Promise<void> {
   run("systemctl", ["--user", "enable", "--now", webServiceName], { check: true });
 
   console.log(`\nPi Web is installed and starting.`);
+  console.log(`Config: ${configPath}`);
   console.log(`Open: http://${options.host === "0.0.0.0" ? "127.0.0.1" : options.host}:${options.port}`);
   console.log("\nUseful commands:");
   console.log("  pi-web status");
@@ -170,7 +191,7 @@ function help(): void {
   console.log(`Pi Web
 
 Usage:
-  pi-web install [--host 127.0.0.1] [--port 3000]
+  pi-web install [--host 127.0.0.1] [--port 8504] [--config ~/.config/pi-web/config.json]
   pi-web uninstall
   pi-web start|stop|restart|status|logs
   pi-web doctor

src/config.ts

@@ -0,0 +1,108 @@
+import { existsSync, readFileSync } from "node:fs";
+import { homedir } from "node:os";
+import { dirname, join, resolve } from "node:path";
+
+export interface PiWebConfig {
+  host?: string;
+  port?: number;
+  allowedHosts?: string[] | true;
+}
+
+export interface LoadedPiWebConfig {
+  path: string;
+  exists: boolean;
+  config: PiWebConfig;
+}
+
+interface LoadOptions {
+  env?: NodeJS.ProcessEnv;
+  cwd?: string;
+}
+
+export function defaultPiWebConfigPath(env: NodeJS.ProcessEnv = process.env): string {
+  const xdgConfigHome = env["XDG_CONFIG_HOME"];
+  return join(xdgConfigHome !== undefined && xdgConfigHome !== "" ? xdgConfigHome : join(homedir(), ".config"), "pi-web", "config.json");
+}
+
+export function piWebConfigPath(env: NodeJS.ProcessEnv = process.env, cwd = process.cwd()): string {
+  const configured = env["PI_WEB_CONFIG"];
+  if (configured === undefined || configured === "") return defaultPiWebConfigPath(env);
+  return resolve(cwd, configured);
+}
+
+export function loadPiWebConfig(options: LoadOptions = {}): LoadedPiWebConfig {
+  const env = options.env ?? process.env;
+  const path = piWebConfigPath(env, options.cwd ?? process.cwd());
+  if (!existsSync(path)) return { path, exists: false, config: {} };
+
+  const parsed: unknown = JSON.parse(readFileSync(path, "utf8"));
+  if (!isRecord(parsed)) throw new Error(`Pi Web config must be a JSON object: ${path}`);
+
+  return { path, exists: true, config: parsePiWebConfig(parsed, path) };
+}
+
+export function effectivePiWebConfig(options: LoadOptions = {}): LoadedPiWebConfig {
+  const loaded = loadPiWebConfig(options);
+  const env = options.env ?? process.env;
+  const host = env["PI_WEB_HOST"];
+  const port = env["PI_WEB_PORT"] ?? env["PORT"];
+  const allowedHosts = env["PI_WEB_ALLOWED_HOSTS"];
+
+  return {
+    ...loaded,
+    config: {
+      ...loaded.config,
+      ...(host !== undefined && host !== "" ? { host } : {}),
+      ...(port !== undefined && port !== "" ? { port: parsePort(port, "PI_WEB_PORT") } : {}),
+      ...(allowedHosts !== undefined && allowedHosts !== "" ? { allowedHosts: parseAllowedHostsEnv(allowedHosts) } : {}),
+    },
+  };
+}
+
+function parsePiWebConfig(value: Record<string, unknown>, path: string): PiWebConfig {
+  return {
+    ...(value["host"] !== undefined ? { host: parseString(value["host"], "host", path) } : {}),
+    ...(value["port"] !== undefined ? { port: parsePort(value["port"], "port", path) } : {}),
+    ...(value["allowedHosts"] !== undefined ? { allowedHosts: parseAllowedHosts(value["allowedHosts"], path) } : {}),
+  };
+}
+
+function parseString(value: unknown, key: string, path: string): string {
+  if (typeof value !== "string" || value === "") throw new Error(`Pi Web config ${key} must be a non-empty string: ${path}`);
+  return value;
+}
+
+function parsePort(value: unknown, key: string, path = "environment"): number {
+  const port = typeof value === "number" ? value : typeof value === "string" && value !== "" ? Number(value) : NaN;
+  if (!Number.isInteger(port) || port < 1 || port > 65535) throw new Error(`Pi Web config ${key} must be an integer from 1 to 65535: ${path}`);
+  return port;
+}
+
+function parseAllowedHosts(value: unknown, path: string): string[] | true {
+  if (value === true) return true;
+  if (!isNonEmptyStringArray(value)) {
+    throw new Error(`Pi Web config allowedHosts must be true or an array of non-empty strings: ${path}`);
+  }
+  return value;
+}
+
+function parseAllowedHostsEnv(value: string): string[] | true {
+  if (value === "true") return true;
+  return value.split(",").map((host) => host.trim()).filter((host) => host !== "");
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value !== null && !Array.isArray(value);
+}
+
+function isNonEmptyStringArray(value: unknown): value is string[] {
+  return Array.isArray(value) && value.every((item) => typeof item === "string" && item !== "");
+}
+
+export function examplePiWebConfig(config: PiWebConfig = {}): string {
+  return `${JSON.stringify({ host: config.host ?? "127.0.0.1", port: config.port ?? 8504, allowedHosts: config.allowedHosts ?? [] }, null, 2)}\n`;
+}
+
+export function piWebConfigDir(env: NodeJS.ProcessEnv = process.env): string {
+  return dirname(defaultPiWebConfigPath(env));
+}

src/server/index.ts

@@ -1,6 +1,6 @@
+import { effectivePiWebConfig } from "../config.js";
 import { buildApp } from "./app.js";
 
 const app = await buildApp();
-const port = Number(process.env["PI_WEB_PORT"] ?? process.env["PORT"] ?? 3000);
-const host = process.env["PI_WEB_HOST"] ?? "127.0.0.1";
-await app.listen({ port, host });
+const { config } = effectivePiWebConfig();
+await app.listen({ port: config.port ?? 8504, host: config.host ?? "127.0.0.1" });