darwin: reliably wait for daemon connection

lib/main.js

@@ -21,6 +21,8 @@ const exec = __importStar(require("@actions/exec"));
 const tc = __importStar(require("@actions/tool-cache"));
 const child_process_1 = require("child_process");
 const os_1 = require("os");
+const process_1 = require("process");
+const net_1 = require("net");
 function nixConf() {
     return __awaiter(this, void 0, void 0, function* () {
         // Workaround a segfault: https://github.com/NixOS/nix/issues/2733
@@ -56,7 +58,7 @@ function run() {
                 // macOS needs certificates hints
                 core.exportVariable('NIX_SSL_CERT_FILE', '/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt');
                 // TODO: nc doesn't work correctly on macOS :(
-                yield exec.exec("sleep", ["10"]);
+                yield awaitSocket();
             }
         }
         catch (error) {
@@ -65,4 +67,17 @@ function run() {
         }
     });
 }
+function awaitSocket() {
+    return __awaiter(this, void 0, void 0, function* () {
+        const daemonSocket = net_1.createConnection({ path: '/nix/var/nix/daemon-socket/socket' });
+        daemonSocket.on('error', () => __awaiter(this, void 0, void 0, function* () {
+            console.log('Waiting for daemon socket to be available, reconnecting...');
+            yield new Promise(resolve => setTimeout(resolve, 500));
+            yield awaitSocket();
+        }));
+        daemonSocket.on('connect', () => {
+            process_1.exit(0);
+        });
+    });
+}
 run();

src/main.ts

@@ -3,6 +3,8 @@ import * as exec from '@actions/exec';
 import * as tc from '@actions/tool-cache';
 import {execFileSync} from 'child_process';
 import {type} from 'os';
+import {exit} from 'process';
+import {createConnection} from 'net';
 
 async function nixConf() {
     // Workaround a segfault: https://github.com/NixOS/nix/issues/2733
@@ -46,7 +48,7 @@ async function run() {
       core.exportVariable('NIX_SSL_CERT_FILE', '/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt');
 
       // TODO: nc doesn't work correctly on macOS :(
-      await exec.exec("sleep", ["10"]);
+      await awaitSocket();
     }
   } catch (error) {
     core.setFailed(`Action failed with error: ${error}`);
@@ -54,4 +56,16 @@ async function run() {
   }
 }
 
+async function awaitSocket() {
+  const daemonSocket = createConnection({ path: '/nix/var/nix/daemon-socket/socket' });
+  daemonSocket.on('error', async () => {
+    console.log('Waiting for daemon socket to be available, reconnecting...');
+    await new Promise(resolve => setTimeout(resolve, 500));
+    await awaitSocket();
+  });
+  daemonSocket.on('connect', () => {
+    exit(0);
+  });
+}
+
 run();