nohup: add option to run command with nohup

NOTE: not guaranteed that shell python class will understand
the connection was reset in time. Also redirects stdout/stderr
to a seperate file.

lisa/node.py

@@ -189,6 +189,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
         cmd: str,
         shell: bool = False,
         sudo: bool = False,
+        nohup: bool = False,
         no_error_log: bool = False,
         no_info_log: bool = True,
         no_debug_log: bool = False,
@@ -202,6 +203,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
             cmd,
             shell=shell,
             sudo=sudo,
+            nohup=nohup,
             no_error_log=no_error_log,
             no_info_log=no_info_log,
             no_debug_log=no_debug_log,
@@ -219,6 +221,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
         cmd: str,
         shell: bool = False,
         sudo: bool = False,
+        nohup: bool = False,
         no_error_log: bool = False,
         no_info_log: bool = True,
         no_debug_log: bool = False,
@@ -236,6 +239,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
             cmd,
             shell=shell,
             sudo=sudo,
+            nohup=nohup,
             no_error_log=no_error_log,
             no_info_log=no_info_log,
             no_debug_log=no_debug_log,
@@ -374,6 +378,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
         cmd: str,
         shell: bool = False,
         sudo: bool = False,
+        nohup: bool = False,
         no_error_log: bool = False,
         no_info_log: bool = False,
         no_debug_log: bool = False,
@@ -386,6 +391,7 @@ class Node(subclasses.BaseClassWithRunbookMixin, ContextMixin, InitializableMixi
             cmd,
             shell=shell,
             sudo=sudo,
+            nohup=nohup,
             no_error_log=no_error_log,
             no_info_log=no_info_log,
             no_debug_log=no_debug_log,

lisa/tools/ip.py

@@ -89,6 +89,7 @@ class Ip(Tool):
             ),
             shell=True,
             sudo=True,
+            nohup=True,
             expected_exit_code=0,
             expected_exit_code_failure_message=(
                 f"fail to restart [down then up] the nic {nic_name}"

lisa/tools/modprobe.py

@@ -26,6 +26,7 @@ class Modprobe(Tool):
             "dhclient -r eth0; dhclient eth0",
             sudo=True,
             shell=True,
+            nohup=True,
         )
 
     def is_module_loaded(

lisa/util/process.py

@@ -80,6 +80,7 @@ class Process:
         self._process: Optional[spur.local.LocalProcess] = None
         self._result: Optional[ExecutableResult] = None
         self._sudo: bool = False
+        self._nohup: bool = False
 
         # add a string stream handler to the logger
         self._log_buffer = io.StringIO()
@@ -91,6 +92,7 @@ class Process:
         command: str,
         shell: bool = False,
         sudo: bool = False,
+        nohup: bool = False,
         cwd: Optional[pathlib.PurePath] = None,
         update_envs: Optional[Dict[str, str]] = None,
         no_error_log: bool = False,
@@ -117,6 +119,7 @@ class Process:
         self._stderr_writer = LogWriter(logger=self.stderr_logger, level=stderr_level)
 
         self._sudo = sudo
+        self._nohup = nohup
 
         if update_envs is None:
             update_envs = {}
@@ -127,7 +130,7 @@ class Process:
             shell = True
 
         update_envs = update_envs.copy()
-        split_command = self._process_command(command, sudo, shell, update_envs)
+        split_command = self._process_command(command, sudo, shell, nohup, update_envs)
 
         cwd_path: Optional[str] = None
         if cwd:
@@ -141,6 +144,7 @@ class Process:
             f"cwd: {cwd_path}, "
             f"shell: {shell}, "
             f"sudo: {sudo}, "
+            f"nohup: {nohup}"
             f"posix: {self._is_posix}, "
             f"remote: {self._shell.is_remote}"
         )
@@ -170,7 +174,12 @@ class Process:
             self._log.log(stderr_level, f"not found command: {identifier}")
 
     def _process_command(
-        self, command: str, sudo: bool, shell: bool, update_envs: Dict[str, str]
+        self,
+        command: str,
+        sudo: bool,
+        shell: bool,
+        nohup: bool,
+        update_envs: Dict[str, str],
     ) -> List[str]:
         # command may be Path object, convert it to str
         command = str(command)
@@ -180,17 +189,23 @@ class Process:
                 split_command = ["cmd", "/c", command]
             else:
                 split_command = []
+                if nohup:
+                    split_command += ["nohup"]
                 if sudo:
                     split_command += ["sudo"]
                 envs = _create_exports(update_envs=update_envs)
                 if envs:
                     command = f"{envs} {command}"
+
                 split_command += ["sh", "-c", command]
                 # expand variables in posix mode
                 update_envs.clear()
         else:
-            if sudo and self._is_posix:
-                command = f"sudo {command}"
+            if self._is_posix:
+                if sudo:
+                    command = f"sudo {command}"
+                if nohup:
+                    command = f"nohup {command}"
             try:
                 split_command = shlex.split(command, posix=self._is_posix)
             except Exception as identifier: