Add instasync cronjob and plumbing for nodejs on nomad clients.

hosts/common/global/packages.nix

@@ -1,6 +1,7 @@
 { pkgs, ... }:
 {
   environment.systemPackages = with pkgs; [
+    nodejs_20
     vim
   ];
 }

hosts/common/nomad.nix

@@ -22,10 +22,16 @@ in
           interface = "tailscale0";
           cidr = "100.64.0.0/10";
         };
-        host_volume.code = {
+        host_volume = {
+          code = {
             path = "/data/compute/code";
             read_only = true;
           };
+          nix-store = {
+            path = "/nix/store";
+            read_only = true;
+          };
+        };
       };
 
       server = {

services/instasync.hcl

@@ -0,0 +1,41 @@
+job "instasync" {
+  datacenters = ["alo"]
+
+  type = "batch"
+
+  periodic {
+    cron = "*/5 * * * *"
+    prohibit_overlap = true
+  }
+
+  group "cron" {
+    volume "code" {
+      type = "host"
+      read_only = true
+      source = "code"
+    }
+    volume "nix-store" {
+      type = "host"
+      read_only = true
+      source = "nix-store"
+    }
+
+    task "sync" {
+      driver = "exec"
+
+      config {
+        command = "/nix/store/2y52nmyfpsq497cppgc43x9v6lkp3q25-nodejs-20.5.1/bin/node"
+        args = ["/code/instasync/sync.js"]
+      }
+
+      volume_mount {
+        volume = "code"
+        destination = "/code"
+      }
+      volume_mount {
+        volume = "nix-store"
+        destination = "/nix/store"
+      }
+    }
+  }
+}