Keep every password, token and API key the vault's, never a setting (hq issue 342)

A setting outranked the vault: baserow, grafana, letta and unifi merged a layer's
password over the ${secret:...} in their runtime config, and the gitea,
home-assistant, icecast, influxdb, mailu and nextcloud clients read the settings
file before the vault's file. A secret in a setting cannot be rotated and is read
back by the settings verb.

The four files now keep their password protected, so the controller refuses a
setting of it. The six clients ignore a secret in the settings file and say so
once, by key and never with the value; icecast reads its admin password from the
vault's file. checks/secrets refuses a mergeable file whose secret a layer could
replace; searxng's nested server.secret_key is listed as known until the
controller protects a nested key.

modules/icecast/client.ts

@@ -42,6 +42,24 @@ function meshConfig(file?: string): Record<string, string> {
   catch { return {}; }
 }
 
+/**
+ * A password, token or API key is the vault's, never a setting (novox/hq issue 342): a value for one of
+ * them in the settings file is ignored, and that is said once — by its key, never with its value.
+ */
+const saidIgnored = new Set<string>();
+function ignoreSecretSetting(cfg: Record<string, unknown>, key: string): void {
+  if (cfg[key] === undefined || saidIgnored.has(key)) return;
+  saidIgnored.add(key);
+  console.error(`the setting ${key} is ignored: it comes from the vault`);
+}
+
+/** A secret delivered as a file, trimmed; undefined when there is none. */
+function readSecret(path: string | undefined): string | undefined {
+  if (!path) return undefined;
+  try { return readFileSync(path, "utf8").trim() || undefined; }
+  catch { return undefined; }
+}
+
 export class IcecastClient {
   readonly baseUrl: string;
   private readonly authHeader?: string;
@@ -57,7 +75,9 @@ export class IcecastClient {
   static fromEnv(env: NodeJS.ProcessEnv = process.env): IcecastClient {
     const cfg = meshConfig(env.MESH_ICECAST_CONFIG_FILE);
     const url = cfg.url ?? (env.MESH_ICECAST_URL ?? `http://127.0.0.1:${env.ICECAST_PORT ?? "8000"}`);
-    return new IcecastClient(url, cfg.user ?? env.MESH_ICECAST_ADMIN_USER, cfg.password ?? env.MESH_ICECAST_ADMIN_PASSWORD);
+    ignoreSecretSetting(cfg, "password");
+    const password = readSecret(env.MESH_ICECAST_ADMIN_PASSWORD_FILE) ?? env.MESH_ICECAST_ADMIN_PASSWORD;
+    return new IcecastClient(url, cfg.user ?? env.MESH_ICECAST_ADMIN_USER ?? "admin", password);
   }
 
   async getStatus(): Promise<IcecastStatus> {

modules/icecast/module.json

@@ -120,7 +120,8 @@
         ],
         "env": {
           "MESH_ICECAST_URL": "http://127.0.0.1:${port:8000}",
-          "MESH_ICECAST_CONFIG_FILE": "${dir:mesh-state}/config.json"
+          "MESH_ICECAST_CONFIG_FILE": "${dir:mesh-state}/config.json",
+          "MESH_ICECAST_ADMIN_PASSWORD_FILE": "${dir:state}/admin.secret"
         }
       }
     ]

modules/icecast/test/secret-setting.test.ts

@@ -0,0 +1,39 @@
+// A password, a token or an API key is the vault's, never a setting (novox/hq issue 342): a value for it in
+// the settings file the mesh merges is ignored, the vault's is used, and that is said once, by the key alone.
+// Run against the compiled module, the way the runtime loads it.
+
+import { test, mock } from "node:test";
+import assert from "node:assert/strict";
+import { mkdtempSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+
+import { IcecastClient } from "../dist/client.js";
+
+const SETTING = "one-a-setting-carried";
+const VAULT = "the-vault-made-this";
+
+function delivered(settings: Record<string, string>): Record<string, string> {
+  const dir = mkdtempSync(join(tmpdir(), "icecast-342-"));
+  writeFileSync(join(dir, "config.json"), JSON.stringify(settings));
+  writeFileSync(join(dir, "vault.secret"), VAULT + "\n");
+  return { dir, config: join(dir, "config.json"), vault: join(dir, "vault.secret") };
+}
+
+test("the vault's password is used, a setting of it is ignored and said once, without its value", () => {
+  const said: string[] = [];
+  const err = mock.method(console, "error", (...args: unknown[]) => { said.push(args.join(" ")); });
+  try {
+    const at = delivered({ password: SETTING });
+    const env = { MESH_ICECAST_CONFIG_FILE: at.config, MESH_ICECAST_ADMIN_PASSWORD_FILE: at.vault };
+    const first = IcecastClient.fromEnv(env);
+    const second = IcecastClient.fromEnv(env);
+    const basic = "Basic " + Buffer.from(`admin:${VAULT}`).toString("base64");
+    assert.equal((first as any).authHeader, basic);
+    assert.equal((second as any).authHeader, basic);
+    assert.deepEqual(said, ["the setting password is ignored: it comes from the vault"]);
+    assert.ok(!said.join("\n").includes(SETTING), "the setting's value is never said");
+  } finally {
+    err.mock.restore();
+  }
+});