[fix] nopy: spawn the pyinfra argv, never a shell string

Closes DOCS-AUDIT §4.2 (point 3, the last one open) and §1.3.

`executeCall` joined `DeployCall.command` and ran it through
`execa({shell: true})`, which made every value on that command line shell
syntax. The finding framed it as a quoting problem "in the password"; it was
wider than that. `--data` values were interpolated inside double quotes, so a
backtick or a `$(…)` in *any* variable value was command substitution and a `;`
ended the command and began another.

`buildDeployCall` now emits a true argv — one element per argument, nothing
pre-quoted — and the executor spawns `execa(command[0], command.slice(1))` with
no `shell` option at all. pyinfra is still found on PATH and stdio stays
inherited, so live output is unchanged.

`maskCommand()` walks the argv by position instead of pattern-matching a joined
string, which closes a leak of its own: it used to bound a secret's value on the
closing `"` the builder had written two modules away, so a value containing a
`"` leaked its own tail. It is now the only thing that turns the command back
into a string, for display, and it shell-quotes as it goes so `--print-only`
output stays pasteable.

Also in `buildDeployCall`: `logConfigToFlags()` finally has a caller (§1.3). It
was exported and unit-tested with nothing consuming it, so `log.verbosity` and
`log.debug` in `.nopyrc.json` did nothing at all. The flags are prefixed onto
the argv right after `-y`. Consequence worth knowing rather than discovering:
`packages/nopy/.nopyrc.json` has always asked for `"verbosity": "trace",
"debug": true`, so a run from that directory now really does get `-vvv --debug`.

The tests move with it — the mock is `execa(file, args, opts)` with no factory
to unwrap, and the new cases are the ones that would have caught this: an argv
element holding `$(id); rm -rf /` stays one element, a secret whose value
contains a quote is masked whole, and `execa` is asserted never to be asked for
a shell.

What remains is not fixable here: the value still reaches pyinfra on its command
line, so it is visible in `ps`. That is pyinfra's `--data` interface.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DCzYTAm9QUhvLNr2EpdagJ

packages/nopy/src/cubes/dependencies.ts

@@ -7,6 +7,7 @@ import type { Cube, CubeVariables, HookContext } from '@bitsquare/nopy-cubes';
 import { getLogger } from '@logtape/logtape';
 import type { Variables } from '../nopy.common.js';
 import type { NopyConfig } from '../nopy.config.js';
+import { logConfigToFlags } from '../nopy.config.js';
 import { NopyUsageError } from '../nopy.errors.js';
 import type { DeployCall } from '../nopy.executor.js';
 import { VariableAssignment } from '../nopy.prompts.js';
@@ -205,6 +206,14 @@ export class BuildContext {
 
   /**
    * Builds and stores a deployment call for a resolved cube
+   *
+   * `command` is a true argv — one array element per argument, nothing
+   * pre-quoted. The executor spawns it without a shell, so a value containing a
+   * space, a quote or a `$(…)` is passed through verbatim instead of being
+   * re-parsed. It used to be a list of fragments joined into one shell string,
+   * which meant any variable value was shell syntax: an SSH password with a `;`
+   * in it ran whatever followed. {@link maskCommand} is the only thing that
+   * turns this back into a string, for display, and quotes as it goes.
    */
   private buildDeployCall(cube: Cube, host: string): void {
     const cubeId = cube.id;
@@ -212,17 +221,17 @@ export class BuildContext {
 
     if (this.resolvedCubes.has(callKey)) return;
 
-    const parts: string[] = [];
+    const parts: string[] = [...logConfigToFlags(this.config.log)];
     if (this.auth.method === 'password' && this.auth.username && this.auth.password) {
-      parts.push(`--user ${this.auth.username} --password ${this.auth.password}`);
+      parts.push('--user', this.auth.username, '--password', this.auth.password);
     }
 
     const cubeVars = this.variables.get(cubeId);
     Object.entries(cubeVars).forEach(([key, value]) => {
-      parts.push(`--data "${key}=${value}"`);
+      parts.push('--data', `${key}=${value}`);
     });
 
-    parts.push(`--chdir ${cube.dir}`);
+    parts.push('--chdir', cube.dir);
     parts.push(`${cube.dir}/${cube.deployScript}`);
 
     const command = ['pyinfra', host, '-y', ...parts];

packages/nopy/src/nopy.executor.ts

@@ -20,7 +20,11 @@ export interface DeployCall {
   host: string;
   /** Working directory for execution */
   cwd: string;
-  /** Full command array */
+  /**
+   * The command as argv — `command[0]` is the executable, the rest are its
+   * arguments, one element each and none of them quoted. Nothing joins this to
+   * run it; {@link maskCommand} joins it to *show* it.
+   */
   command: string[];
   /** Environment variables for the cube */
   env: Record<string, unknown>;
@@ -30,6 +34,18 @@ export interface DeployCall {
   dependencies: DependencySpec[];
 }
 
+/**
+ * One argv element, quoted for a POSIX shell.
+ *
+ * Display only — nothing is executed through a shell any more. The point is
+ * that what `--print-only` writes can be pasted into a terminal and mean the
+ * same thing it meant here.
+ */
+function shellQuote(arg: string): string {
+  if (arg.length > 0 && /^[\w@%+=:,./-]+$/.test(arg)) return arg;
+  return `'${arg.replace(/'/g, `'\\''`)}'`;
+}
+
 /**
  * The command as it is safe to show: the SSH password, and every `--data KEY=…`
  * whose key the manifest declared a secret, have their values replaced.
@@ -37,18 +53,37 @@ export interface DeployCall {
  * pyinfra takes its data on the command line, so the real values have to be in
  * `call.command` — this is the last point before they would reach a log, a
  * `--print-only` dump or a dry-run plan.
+ *
+ * Walks the argv rather than pattern-matching a joined string. The old version
+ * bounded a `--data` value on the closing quote the builder had written, which
+ * tied masking to a quoting convention two modules apart; a value containing a
+ * `"` broke it, and it was the same brittleness that made the command a shell
+ * injection in the first place. Position is not guessable.
  */
 export function maskCommand(call: DeployCall): string {
-  const command = call.command.join(' ');
-  const quoteMeta = (key: string) => key.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+  const secrets = new Set(call.secrets ?? []);
+  const argv = call.command;
+  const out: string[] = [];
 
-  // The builder always quotes a `--data` value, so the closing quote bounds it.
-  const masked = (call.secrets ?? []).reduce(
-    (acc, key) => acc.replace(new RegExp(`(--data "${quoteMeta(key)}=)[^"]*"`, 'g'), `$1${MASK}"`),
-    command
-  );
+  for (let i = 0; i < argv.length; i++) {
+    const arg = argv[i];
+    const next = argv[i + 1];
 
-  return masked.replace(/(--password )\S+/g, `$1${MASK}`);
+    if (arg === '--password' && next !== undefined) {
+      out.push(arg, MASK);
+      i++;
+    } else if (arg === '--data' && next !== undefined) {
+      // Split on the first `=` only: the key cannot contain one, the value can.
+      const eq = next.indexOf('=');
+      const key = eq === -1 ? next : next.slice(0, eq);
+      out.push(arg, secrets.has(key) ? `${key}=${MASK}` : shellQuote(next));
+      i++;
+    } else {
+      out.push(shellQuote(arg));
+    }
+  }
+
+  return out.join(' ');
 }
 
 /**
@@ -107,14 +142,18 @@ export interface ExecutionOptions {
  */
 async function executeCall(call: DeployCall): Promise<ExecutionResult> {
   const startTime = Date.now();
-  const commandStr = call.command.join(' ');
+  const [file, ...args] = call.command;
 
   try {
     log.info(`Executing: ${call.cube} -> ${call.host}`);
     log.debug(`Command: ${maskCommand(call)}`);
 
-    // Inherit stdio for live output
-    await execa({ shell: true })(commandStr, {
+    // No shell. `execa({shell: true})` used to run the whole command as one
+    // string, which made every variable value shell syntax — a password or a
+    // `--data` value containing `;`, a backtick or `$(…)` was executed rather
+    // than passed along. Spawning the argv directly removes the parse step;
+    // pyinfra is still found on PATH, and stdio stays inherited for live output.
+    await execa(file, args, {
       cwd: call.cwd,
       stdio: 'inherit',
     });