add server settings store

apps/ignis-server/server/settings.js

@@ -0,0 +1,91 @@
+const fs = require("fs");
+const path = require("path");
+const config = require("./config");
+
+// Runtime server settings set through UI.
+
+const SETTINGS_FILE = path.join(config.dataRoot, "server-settings.json");
+
+const DEFAULTS = {
+  contentCacheBytes: 50 * 1024 * 1024,
+  inputCacheBytes: 200 * 1024 * 1024,
+  inputCacheTtlMs: 5 * 60 * 1000,
+  writeCoalesceMs: 5000,
+  maxBodyBytes: 50 * 1024 * 1024,
+  // Empty arrays mean "no restriction": any proxy host, any WS origin.
+  proxyAllowlist: [],
+  wsOrigins: [],
+};
+
+const KEYS = Object.keys(DEFAULTS);
+
+function parseList(raw) {
+  return raw
+    .split(",")
+    .map((s) => s.trim())
+    .filter(Boolean);
+}
+
+function fromEnv() {
+  const env = {};
+
+  if (process.env.WRITE_COALESCE_MS !== undefined) {
+    const n = parseInt(process.env.WRITE_COALESCE_MS, 10);
+
+    if (Number.isFinite(n)) {
+      env.writeCoalesceMs = n;
+    }
+  }
+
+  if (process.env.WS_ORIGINS) {
+    env.wsOrigins = parseList(process.env.WS_ORIGINS);
+  }
+
+  return env;
+}
+
+const envOverrides = fromEnv();
+
+function loadFile() {
+  try {
+    const parsed = JSON.parse(fs.readFileSync(SETTINGS_FILE, "utf-8"));
+    // Keep only known keys so a stale or hand-edited file can't inject junk.
+    const clean = {};
+
+    for (const key of KEYS) {
+      if (parsed[key] !== undefined) {
+        clean[key] = parsed[key];
+      }
+    }
+
+    return clean;
+  } catch {
+    return {};
+  }
+}
+
+let fileOverrides = loadFile();
+
+function getAll() {
+  return { ...DEFAULTS, ...envOverrides, ...fileOverrides };
+}
+
+function get(key) {
+  return getAll()[key];
+}
+
+// Merge validated changes into the persisted file and return the new effective settings.
+function update(partial) {
+  for (const [key, value] of Object.entries(partial)) {
+    if (KEYS.includes(key)) {
+      fileOverrides[key] = value;
+    }
+  }
+
+  fs.mkdirSync(path.dirname(SETTINGS_FILE), { recursive: true });
+  fs.writeFileSync(SETTINGS_FILE, JSON.stringify(fileOverrides, null, 2));
+
+  return getAll();
+}
+
+module.exports = { DEFAULTS, KEYS, getAll, get, update };