Merge pull request #75 from truenas/lock

NAS-128183 / 24.10 / Allow running multiple installers (on different terminals). Introduce…

truenas_installer/__main__.py

@@ -1,38 +1,13 @@
-import os
-import pathlib
-import sys
-
-import psutil
-
 from ixhardware import parse_dmi
 
 from .installer import Installer
 
 
 if __name__ == "__main__":
-    pidfile = pathlib.Path("/run/truenas_installer.pid")
-    try:
-        pid = int(pidfile.read_text().strip())
-    except (FileNotFoundError, UnicodeDecodeError, ValueError):
-        pass
-    else:
-        try:
-            process = psutil.Process(pid)
-        except psutil.NoSuchProcess:
-            pass
-        else:
-            if "truenas_installer" in process.cmdline():
-                print(f"Installer is already running (pid={pid})", file=sys.stderr)
-                sys.exit(1)
-
-    pidfile.write_text(str(os.getpid()))
-    try:
-        with open("/etc/version") as f:
-            version = f.read().strip()
+    with open("/etc/version") as f:
+        version = f.read().strip()
 
-        dmi = parse_dmi()
+    dmi = parse_dmi()
 
-        installer = Installer(version, dmi)
-        installer.run()
-    finally:
-        pidfile.unlink(missing_ok=True)
+    installer = Installer(version, dmi)
+    installer.run()

truenas_installer/exception.py

@@ -0,0 +1,7 @@
+__all__ = ["InstallError"]
+
+
+class InstallError(Exception):
+    def __init__(self, message):
+        self.message = message
+        super().__init__(message)

truenas_installer/install.py

@@ -1,41 +1,37 @@
-import os.path
-
 import asyncio
 import json
+import os
 import pathlib
 import subprocess
 import tempfile
 
+from .exception import InstallError
+from .lock import installation_lock
 from .utils import get_partition, run
 
 __all__ = ["InstallError", "install"]
 
 BOOT_POOL = "boot-pool"
 
 
-class InstallError(Exception):
-    def __init__(self, message):
-        self.message = message
-        super().__init__(message)
-
-
 async def install(disks, create_swap, set_pmbr, authentication, sql, callback):
-    try:
-        if not os.path.exists("/etc/hostid"):
-            await run(["zgenhostid"])
-
-        for disk in disks:
-            callback(0, f"Formatting disk {disk}")
-            await format_disk(f"/dev/{disk}", create_swap, set_pmbr, callback)
-
-        callback(0, "Creating boot pool")
-        await create_boot_pool([get_partition(disk, 3) for disk in disks])
+    with installation_lock:
         try:
-            await run_installer(disks, authentication, sql, callback)
-        finally:
-            await run(["zpool", "export", "-f", BOOT_POOL])
-    except subprocess.CalledProcessError as e:
-        raise InstallError(f"Command {' '.join(e.cmd)} failed:\n{e.stderr.rstrip()}")
+            if not os.path.exists("/etc/hostid"):
+                await run(["zgenhostid"])
+
+            for disk in disks:
+                callback(0, f"Formatting disk {disk}")
+                await format_disk(f"/dev/{disk}", create_swap, set_pmbr, callback)
+
+            callback(0, "Creating boot pool")
+            await create_boot_pool([get_partition(disk, 3) for disk in disks])
+            try:
+                await run_installer(disks, authentication, sql, callback)
+            finally:
+                await run(["zpool", "export", "-f", BOOT_POOL])
+        except subprocess.CalledProcessError as e:
+            raise InstallError(f"Command {' '.join(e.cmd)} failed:\n{e.stderr.rstrip()}")
 
 
 async def format_disk(device, create_swap, set_pmbr, callback):

truenas_installer/installer_menu.py

@@ -6,7 +6,8 @@
 
 from .dialog import dialog_checklist, dialog_menu, dialog_msgbox, dialog_password, dialog_yesno
 from .disks import list_disks
-from .install import InstallError, install
+from .exception import InstallError
+from .install import install
 from .serial import serial_sql
 from .swap import is_swap_safe
 

truenas_installer/lock.py

@@ -0,0 +1,25 @@
+import pathlib
+
+from .exception import InstallError
+
+__all__ = ["installation_lock"]
+
+
+class InstallationLock:
+    def __init__(self):
+        self.path = pathlib.Path("/run/truenas_installer.lock")
+
+    def locked(self):
+        return self.path.exists()
+
+    def __enter__(self):
+        if self.locked():
+            raise InstallError("Installation is already in progress")
+
+        self.path.write_text("")
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.path.unlink(missing_ok=True)
+
+
+installation_lock = InstallationLock()