salt/add-salt-ssh-support-with-venv-salt-minion-3004-493.patch

From 3fd6c0c6793632c819fb5f8fb3b3538463eaaccc Mon Sep 17 00:00:00 2001
From: Victor Zhestkov <vzhestkov@suse.com>
Date: Thu, 24 Feb 2022 16:52:24 +0300
Subject: [PATCH] Add salt-ssh support with venv-salt-minion - 3004
 (#493)

* Add salt-ssh support with venv-salt-minion

* Add some comments and drop the commented line

* Fix return in check_venv_hash_file

* Convert all script parameters to strings

* Reduce the size of minion response

Minion response contains SSH_PY_CODE wrapped to base64.
This fix reduces the size of the response in DEBUG logging

* Make VENV_HASH_FILE global

* Pass the context to roster modules

* Avoid race condition on loading roster modules

* Prevent simultaneous to salt-ssh minion

* Make ssh session grace time configurable

* Prevent possible segfault by GC

* Revert "Avoid race condition on loading roster modules"

This reverts commit 8ff822a162cc494d3528184aef983ad20e09f4e2.

* Prevent deadlocks with importlib on using LazyLoader

* Make logging on salt-ssh errors more informative

* Add comments about using salt.loader.LOAD_LOCK

* Fix test_loader test

* Prevent deadlocks on using logging

* Use collections.deque instead of list for salt-ssh

Suggested by @agraul

* Get proper exitstatus from salt.utils.vt.Terminal

to prevent empty event returns due to improperly detecting
the child process as failed

* Do not run pre flight script for raw_shell
---
 salt/_logging/impl.py          |  55 +++++++-----
 salt/client/ssh/__init__.py    | 157 ++++++++++++++++++++++++++++-----
 salt/client/ssh/client.py      |   7 +-
 salt/client/ssh/shell.py       |   8 ++
 salt/client/ssh/ssh_py_shim.py | 108 +++++++++++++----------
 salt/loader/__init__.py        |  31 ++++++-
 salt/netapi/__init__.py        |   3 +-
 salt/roster/__init__.py        |   6 +-
 tests/unit/test_loader.py      |   2 +-
 9 files changed, 278 insertions(+), 99 deletions(-)

diff --git a/salt/_logging/impl.py b/salt/_logging/impl.py
index cc18f49a9e..e050f43caf 100644
--- a/salt/_logging/impl.py
+++ b/salt/_logging/impl.py
@@ -14,6 +14,7 @@ import re
 import socket
 import sys
 import traceback
+import threading
 import types
 import urllib.parse
 
@@ -104,6 +105,10 @@ DFLT_LOG_DATEFMT_LOGFILE = "%Y-%m-%d %H:%M:%S"
 DFLT_LOG_FMT_CONSOLE = "[%(levelname)-8s] %(message)s"
 DFLT_LOG_FMT_LOGFILE = "%(asctime)s,%(msecs)03d [%(name)-17s:%(lineno)-4d][%(levelname)-8s][%(process)d] %(message)s"
 
+# LOG_LOCK is used to prevent deadlocks on using logging
+# in combination with multiprocessing with salt-api
+LOG_LOCK = threading.Lock()
+
 
 class SaltLogRecord(logging.LogRecord):
     def __init__(self, *args, **kwargs):
@@ -270,27 +275,35 @@ class SaltLoggingClass(LOGGING_LOGGER_CLASS, metaclass=LoggingMixinMeta):
         else:
             extra["exc_info_on_loglevel"] = exc_info_on_loglevel
 
-        if sys.version_info < (3, 8):
-            LOGGING_LOGGER_CLASS._log(
-                self,
-                level,
-                msg,
-                args,
-                exc_info=exc_info,
-                extra=extra,
-                stack_info=stack_info,
-            )
-        else:
-            LOGGING_LOGGER_CLASS._log(
-                self,
-                level,
-                msg,
-                args,
-                exc_info=exc_info,
-                extra=extra,
-                stack_info=stack_info,
-                stacklevel=stacklevel,
-            )
+        try:
+            LOG_LOCK.acquire()
+            if sys.version_info < (3,):
+                LOGGING_LOGGER_CLASS._log(
+                    self, level, msg, args, exc_info=exc_info, extra=extra
+                )
+            elif sys.version_info < (3, 8):
+                LOGGING_LOGGER_CLASS._log(
+                    self,
+                    level,
+                    msg,
+                    args,
+                    exc_info=exc_info,
+                    extra=extra,
+                    stack_info=stack_info,
+                )
+            else:
+                LOGGING_LOGGER_CLASS._log(
+                    self,
+                    level,
+                    msg,
+                    args,
+                    exc_info=exc_info,
+                    extra=extra,
+                    stack_info=stack_info,
+                    stacklevel=stacklevel,
+                )
+        finally:
+            LOG_LOCK.release()
 
     def makeRecord(
         self,
diff --git a/salt/client/ssh/__init__.py b/salt/client/ssh/__init__.py
index 19089ce8ad..e6837df4e5 100644
--- a/salt/client/ssh/__init__.py
+++ b/salt/client/ssh/__init__.py
@@ -6,11 +6,13 @@ import base64
 import binascii
 import copy
 import datetime
+import gc
 import getpass
 import hashlib
 import logging
 import multiprocessing
 import os
+import psutil
 import queue
 import re
 import shlex
@@ -20,6 +22,7 @@ import tarfile
 import tempfile
 import time
 import uuid
+from collections import deque
 
 import salt.client.ssh.shell
 import salt.client.ssh.wrapper
@@ -47,6 +50,7 @@ import salt.utils.url
 import salt.utils.verify
 from salt._logging import LOG_LEVELS
 from salt._logging.mixins import MultiprocessingStateMixin
+from salt._logging.impl import LOG_LOCK
 from salt.template import compile_template
 from salt.utils.process import Process
 from salt.utils.zeromq import zmq
@@ -146,15 +150,26 @@ if [ "$SUDO" ] && [ "$SUDO_USER" ]
 then SUDO="$SUDO -u $SUDO_USER"
 fi
 EX_PYTHON_INVALID={EX_THIN_PYTHON_INVALID}
-PYTHON_CMDS="python3 /usr/libexec/platform-python python27 python2.7 python26 python2.6 python2 python"
+set +x
+SSH_PY_CODE='import base64;
+                   exec(base64.b64decode("""{{SSH_PY_CODE}}""").decode("utf-8"))'
+if [ -n "$DEBUG" ]
+    then set -x
+fi
+PYTHON_CMDS="/var/tmp/venv-salt-minion/bin/python python3 /usr/libexec/platform-python python27 python2.7 python26 python2.6 python2 python"
 for py_cmd in $PYTHON_CMDS
 do
     if command -v "$py_cmd" >/dev/null 2>&1 && "$py_cmd" -c "import sys; sys.exit(not (sys.version_info >= (2, 6)));"
     then
         py_cmd_path=`"$py_cmd" -c 'from __future__ import print_function;import sys; print(sys.executable);'`
         cmdpath=`command -v $py_cmd 2>/dev/null || which $py_cmd 2>/dev/null`
+        cmdpath=`readlink -f $cmdpath`
         if file $cmdpath | grep "shell script" > /dev/null
         then
+            if echo $cmdpath | grep venv-salt-minion > /dev/null
+            then
+                exec $SUDO "$cmdpath" -c "$SSH_PY_CODE"
+            fi
             ex_vars="'PATH', 'LD_LIBRARY_PATH', 'MANPATH', \
                    'XDG_DATA_DIRS', 'PKG_CONFIG_PATH'"
             export `$py_cmd -c \
@@ -166,13 +181,9 @@ do
             exec $SUDO PATH=$PATH LD_LIBRARY_PATH=$LD_LIBRARY_PATH \
                      MANPATH=$MANPATH XDG_DATA_DIRS=$XDG_DATA_DIRS \
                      PKG_CONFIG_PATH=$PKG_CONFIG_PATH \
-                     "$py_cmd_path" -c \
-                   'import base64;
-                   exec(base64.b64decode("""{{SSH_PY_CODE}}""").decode("utf-8"))'
+                     "$py_cmd_path" -c "$SSH_PY_CODE"
         else
-            exec $SUDO "$py_cmd_path" -c \
-                   'import base64;
-                   exec(base64.b64decode("""{{SSH_PY_CODE}}""").decode("utf-8"))'
+            exec $SUDO "$py_cmd_path" -c "$SSH_PY_CODE"
         fi
         exit 0
     else
@@ -189,6 +200,9 @@ EOF'''.format(
     ]
 )
 
+# The file on a salt-ssh minion used to identify if Salt Bundle was deployed
+VENV_HASH_FILE = "/var/tmp/venv-salt-minion/venv-hash.txt"
+
 if not salt.utils.platform.is_windows() and not salt.utils.platform.is_junos():
     shim_file = os.path.join(os.path.dirname(__file__), "ssh_py_shim.py")
     if not os.path.exists(shim_file):
@@ -209,7 +223,7 @@ class SSH(MultiprocessingStateMixin):
 
     ROSTER_UPDATE_FLAG = "#__needs_update"
 
-    def __init__(self, opts):
+    def __init__(self, opts, context=None):
         self.__parsed_rosters = {SSH.ROSTER_UPDATE_FLAG: True}
         pull_sock = os.path.join(opts["sock_dir"], "master_event_pull.ipc")
         if os.path.exists(pull_sock) and zmq:
@@ -236,7 +250,9 @@ class SSH(MultiprocessingStateMixin):
             else "glob"
         )
         self._expand_target()
-        self.roster = salt.roster.Roster(self.opts, self.opts.get("roster", "flat"))
+        self.roster = salt.roster.Roster(
+            self.opts, self.opts.get("roster", "flat"), context=context
+        )
         self.targets = self.roster.targets(self.opts["tgt"], self.tgt_type)
         if not self.targets:
             self._update_targets()
@@ -316,6 +332,13 @@ class SSH(MultiprocessingStateMixin):
             extended_cfg=self.opts.get("ssh_ext_alternatives"),
         )
         self.mods = mod_data(self.fsclient)
+        self.cache = salt.cache.Cache(self.opts)
+        self.master_id = self.opts["id"]
+        self.max_pid_wait = int(self.opts.get("ssh_max_pid_wait", 600))
+        self.session_flock_file = os.path.join(
+            self.opts["cachedir"], "salt-ssh.session.lock"
+        )
+        self.ssh_session_grace_time = int(self.opts.get("ssh_session_grace_time", 3))
 
     # __setstate__ and __getstate__ are only used on spawning platforms.
     def __setstate__(self, state):
@@ -546,6 +569,8 @@ class SSH(MultiprocessingStateMixin):
         """
         Run the routine in a "Thread", put a dict on the queue
         """
+        LOG_LOCK.release()
+        salt.loader.LOAD_LOCK.release()
         opts = copy.deepcopy(opts)
         single = Single(
             opts,
@@ -585,7 +610,7 @@ class SSH(MultiprocessingStateMixin):
         """
         que = multiprocessing.Queue()
         running = {}
-        target_iter = self.targets.__iter__()
+        targets_queue = deque(self.targets.keys())
         returned = set()
         rets = set()
         init = False
@@ -594,11 +619,43 @@ class SSH(MultiprocessingStateMixin):
                 log.error("No matching targets found in roster.")
                 break
             if len(running) < self.opts.get("ssh_max_procs", 25) and not init:
-                try:
-                    host = next(target_iter)
-                except StopIteration:
+                if targets_queue:
+                    host = targets_queue.popleft()
+                else:
                     init = True
                     continue
+                with salt.utils.files.flopen(self.session_flock_file, "w"):
+                    cached_session = self.cache.fetch("salt-ssh/session", host)
+                    if cached_session is not None and "ts" in cached_session:
+                        prev_session_running = time.time() - cached_session["ts"]
+                        if (
+                            "pid" in cached_session
+                            and cached_session.get("master_id", self.master_id)
+                            == self.master_id
+                        ):
+                            pid_running = (
+                                False
+                                if cached_session["pid"] == 0
+                                else psutil.pid_exists(cached_session["pid"])
+                            )
+                            if (
+                                pid_running and prev_session_running < self.max_pid_wait
+                            ) or (
+                                not pid_running
+                                and prev_session_running < self.ssh_session_grace_time
+                            ):
+                                targets_queue.append(host)
+                                time.sleep(0.3)
+                                continue
+                    self.cache.store(
+                        "salt-ssh/session",
+                        host,
+                        {
+                            "pid": 0,
+                            "master_id": self.master_id,
+                            "ts": time.time(),
+                        },
+                    )
                 for default in self.defaults:
                     if default not in self.targets[host]:
                         self.targets[host][default] = self.defaults[default]
@@ -630,8 +687,38 @@ class SSH(MultiprocessingStateMixin):
                     mine,
                 )
                 routine = Process(target=self.handle_routine, args=args)
-                routine.start()
+                # Explicitly call garbage collector to prevent possible segfault
+                # in salt-api child process. (bsc#1188607)
+                gc.collect()
+                try:
+                    # salt.loader.LOAD_LOCK is used to prevent deadlock
+                    # with importlib in combination with using multiprocessing (bsc#1182851)
+                    # If the salt-api child process is creating while LazyLoader instance
+                    # is loading module, new child process gets the lock for this module acquired.
+                    # Touching this module with importlib inside child process leads to deadlock.
+                    #
+                    # salt.loader.LOAD_LOCK is used to prevent salt-api child process creation
+                    # while creating new instance of LazyLoader
+                    # salt.loader.LOAD_LOCK must be released explicitly in self.handle_routine
+                    salt.loader.LOAD_LOCK.acquire()
+                    # The same solution applied to fix logging deadlock
+                    # LOG_LOCK must be released explicitly in self.handle_routine
+                    LOG_LOCK.acquire()
+                    routine.start()
+                finally:
+                    LOG_LOCK.release()
+                    salt.loader.LOAD_LOCK.release()
                 running[host] = {"thread": routine}
+                with salt.utils.files.flopen(self.session_flock_file, "w"):
+                    self.cache.store(
+                        "salt-ssh/session",
+                        host,
+                        {
+                            "pid": routine.pid,
+                            "master_id": self.master_id,
+                            "ts": time.time(),
+                        },
+                    )
                 continue
             ret = {}
             try:
@@ -662,12 +749,27 @@ class SSH(MultiprocessingStateMixin):
                             )
                             ret = {"id": host, "ret": error}
                             log.error(error)
+                            log.error(
+                                "PID %s did not return any data for host '%s'",
+                                running[host]["thread"].pid,
+                                host,
+                            )
                             yield {ret["id"]: ret["ret"]}
                     running[host]["thread"].join()
                     rets.add(host)
             for host in rets:
                 if host in running:
                     running.pop(host)
+                    with salt.utils.files.flopen(self.session_flock_file, "w"):
+                        self.cache.store(
+                            "salt-ssh/session",
+                            host,
+                            {
+                                "pid": 0,
+                                "master_id": self.master_id,
+                                "ts": time.time(),
+                            },
+                        )
             if len(rets) >= len(self.targets):
                 break
             # Sleep when limit or all threads started
@@ -1036,14 +1138,24 @@ class Single:
             return False
         return True
 
+    def check_venv_hash_file(self):
+        """
+        check if the venv exists on the remote machine
+        """
+        stdout, stderr, retcode = self.shell.exec_cmd(
+            "test -f {}".format(VENV_HASH_FILE)
+        )
+        return retcode == 0
+
     def deploy(self):
         """
         Deploy salt-thin
         """
-        self.shell.send(
-            self.thin,
-            os.path.join(self.thin_dir, "salt-thin.tgz"),
-        )
+        if not self.check_venv_hash_file():
+            self.shell.send(
+                self.thin,
+                os.path.join(self.thin_dir, "salt-thin.tgz"),
+            )
         self.deploy_ext()
         return True
 
@@ -1071,8 +1183,9 @@ class Single:
         Returns tuple of (stdout, stderr, retcode)
         """
         stdout = stderr = retcode = None
+        raw_shell = self.opts.get("raw_shell", False)
 
-        if self.ssh_pre_flight:
+        if self.ssh_pre_flight and not raw_shell:
             if not self.opts.get("ssh_run_pre_flight", False) and self.check_thin_dir():
                 log.info(
                     "%s thin dir already exists. Not running ssh_pre_flight script",
@@ -1086,14 +1199,16 @@ class Single:
                 stdout, stderr, retcode = self.run_ssh_pre_flight()
                 if retcode != 0:
                     log.error(
-                        "Error running ssh_pre_flight script %s", self.ssh_pre_file
+                        "Error running ssh_pre_flight script %s for host '%s'",
+                        self.ssh_pre_file,
+                        self.target["host"],
                     )
                     return stdout, stderr, retcode
                 log.info(
                     "Successfully ran the ssh_pre_flight script: %s", self.ssh_pre_file
                 )
 
-        if self.opts.get("raw_shell", False):
+        if raw_shell:
             cmd_str = " ".join([self._escape_arg(arg) for arg in self.argv])
             stdout, stderr, retcode = self.shell.exec_cmd(cmd_str)
 
diff --git a/salt/client/ssh/client.py b/salt/client/ssh/client.py
index be9247cb15..0b67598fc6 100644
--- a/salt/client/ssh/client.py
+++ b/salt/client/ssh/client.py
@@ -108,7 +108,7 @@ class SSHClient:
         return sane_kwargs
 
     def _prep_ssh(
-        self, tgt, fun, arg=(), timeout=None, tgt_type="glob", kwarg=None, **kwargs
+        self, tgt, fun, arg=(), timeout=None, tgt_type="glob", kwarg=None, context=None, **kwargs
     ):
         """
         Prepare the arguments
@@ -123,7 +123,7 @@ class SSHClient:
         opts["selected_target_option"] = tgt_type
         opts["tgt"] = tgt
         opts["arg"] = arg
-        return salt.client.ssh.SSH(opts)
+        return salt.client.ssh.SSH(opts, context=context)
 
     def cmd_iter(
         self,
@@ -160,7 +160,7 @@ class SSHClient:
             final.update(ret)
         return final
 
-    def cmd_sync(self, low):
+    def cmd_sync(self, low, context=None):
         """
         Execute a salt-ssh call synchronously.
 
@@ -193,6 +193,7 @@ class SSHClient:
             low.get("timeout"),
             low.get("tgt_type"),
             low.get("kwarg"),
+            context=context,
             **kwargs
         )
 
diff --git a/salt/client/ssh/shell.py b/salt/client/ssh/shell.py
index cfa82d13c2..bc1ad034df 100644
--- a/salt/client/ssh/shell.py
+++ b/salt/client/ssh/shell.py
@@ -464,6 +464,14 @@ class Shell:
                 if stdout:
                     old_stdout = stdout
                 time.sleep(0.01)
+            if term.exitstatus is None:
+                try:
+                    term.wait()
+                except:  # pylint: disable=broad-except
+                    # It's safe to put the broad exception handling here
+                    # as we just need to ensure the child process in term finished
+                    # to get proper term.exitstatus instead of None
+                    pass
             return ret_stdout, ret_stderr, term.exitstatus
         finally:
             term.close(terminate=True, kill=True)
diff --git a/salt/client/ssh/ssh_py_shim.py b/salt/client/ssh/ssh_py_shim.py
index b77749f495..293ea1b7fa 100644
--- a/salt/client/ssh/ssh_py_shim.py
+++ b/salt/client/ssh/ssh_py_shim.py
@@ -279,56 +279,72 @@ def main(argv):  # pylint: disable=W0613
     """
     Main program body
     """
-    thin_path = os.path.join(OPTIONS.saltdir, THIN_ARCHIVE)
-    if os.path.isfile(thin_path):
-        if OPTIONS.checksum != get_hash(thin_path, OPTIONS.hashfunc):
-            need_deployment()
-        unpack_thin(thin_path)
-        # Salt thin now is available to use
-    else:
-        if not sys.platform.startswith("win"):
-            scpstat = subprocess.Popen(["/bin/sh", "-c", "command -v scp"]).wait()
-            if scpstat != 0:
-                sys.exit(EX_SCP_NOT_FOUND)
-
-        if os.path.exists(OPTIONS.saltdir) and not os.path.isdir(OPTIONS.saltdir):
-            sys.stderr.write(
-                'ERROR: salt path "{0}" exists but is not a directory\n'.format(
-                    OPTIONS.saltdir
+
+    virt_env = os.getenv("VIRTUAL_ENV", None)
+    # VIRTUAL_ENV environment variable is defined by venv-salt-minion wrapper
+    # it's used to check if the shim is running under this wrapper
+    venv_salt_call = None
+    if virt_env and "venv-salt-minion" in virt_env:
+        venv_salt_call = os.path.join(virt_env, "bin", "salt-call")
+        if not os.path.exists(venv_salt_call):
+            venv_salt_call = None
+        elif not os.path.exists(OPTIONS.saltdir):
+            os.makedirs(OPTIONS.saltdir)
+            cache_dir = os.path.join(OPTIONS.saltdir, "running_data", "var", "cache")
+            os.makedirs(os.path.join(cache_dir, "salt"))
+            os.symlink("salt", os.path.relpath(os.path.join(cache_dir, "venv-salt-minion")))
+
+    if venv_salt_call is None:
+        # Use Salt thin only if Salt Bundle (venv-salt-minion) is not available
+        thin_path = os.path.join(OPTIONS.saltdir, THIN_ARCHIVE)
+        if os.path.isfile(thin_path):
+            if OPTIONS.checksum != get_hash(thin_path, OPTIONS.hashfunc):
+                need_deployment()
+            unpack_thin(thin_path)
+            # Salt thin now is available to use
+        else:
+            if not sys.platform.startswith("win"):
+                scpstat = subprocess.Popen(["/bin/sh", "-c", "command -v scp"]).wait()
+                if scpstat != 0:
+                    sys.exit(EX_SCP_NOT_FOUND)
+
+            if os.path.exists(OPTIONS.saltdir) and not os.path.isdir(OPTIONS.saltdir):
+                sys.stderr.write(
+                    'ERROR: salt path "{0}" exists but is'
+                    " not a directory\n".format(OPTIONS.saltdir)
                 )
-            )
-            sys.exit(EX_CANTCREAT)
+                sys.exit(EX_CANTCREAT)
 
-        if not os.path.exists(OPTIONS.saltdir):
-            need_deployment()
+            if not os.path.exists(OPTIONS.saltdir):
+                need_deployment()
 
-        code_checksum_path = os.path.normpath(
-            os.path.join(OPTIONS.saltdir, "code-checksum")
-        )
-        if not os.path.exists(code_checksum_path) or not os.path.isfile(
-            code_checksum_path
-        ):
-            sys.stderr.write(
-                "WARNING: Unable to locate current code checksum: {0}.\n".format(
-                    code_checksum_path
-                )
+            code_checksum_path = os.path.normpath(
+                os.path.join(OPTIONS.saltdir, "code-checksum")
             )
-            need_deployment()
-        with open(code_checksum_path, "r") as vpo:
-            cur_code_cs = vpo.readline().strip()
-        if cur_code_cs != OPTIONS.code_checksum:
-            sys.stderr.write(
-                "WARNING: current code checksum {0} is different to {1}.\n".format(
-                    cur_code_cs, OPTIONS.code_checksum
+            if not os.path.exists(code_checksum_path) or not os.path.isfile(
+                code_checksum_path
+            ):
+                sys.stderr.write(
+                    "WARNING: Unable to locate current code checksum: {0}.\n".format(
+                        code_checksum_path
+                    )
                 )
-            )
-            need_deployment()
-        # Salt thin exists and is up-to-date - fall through and use it
+                need_deployment()
+            with open(code_checksum_path, "r") as vpo:
+                cur_code_cs = vpo.readline().strip()
+            if cur_code_cs != OPTIONS.code_checksum:
+                sys.stderr.write(
+                    "WARNING: current code checksum {0} is different to {1}.\n".format(
+                        cur_code_cs, OPTIONS.code_checksum
+                    )
+                )
+                need_deployment()
+            # Salt thin exists and is up-to-date - fall through and use it
 
-    salt_call_path = os.path.join(OPTIONS.saltdir, "salt-call")
-    if not os.path.isfile(salt_call_path):
-        sys.stderr.write('ERROR: thin is missing "{0}"\n'.format(salt_call_path))
-        need_deployment()
+        salt_call_path = os.path.join(OPTIONS.saltdir, "salt-call")
+        if not os.path.isfile(salt_call_path):
+            sys.stderr.write('ERROR: thin is missing "{0}"\n'.format(salt_call_path))
+            need_deployment()
 
     with open(os.path.join(OPTIONS.saltdir, "minion"), "w") as config:
         config.write(OPTIONS.config + "\n")
@@ -351,8 +367,8 @@ def main(argv):  # pylint: disable=W0613
         argv_prepared = ARGS
 
     salt_argv = [
-        get_executable(),
-        salt_call_path,
+        sys.executable if venv_salt_call is not None else get_executable(),
+        venv_salt_call if venv_salt_call is not None else salt_call_path,
         "--retcode-passthrough",
         "--local",
         "--metadata",
diff --git a/salt/loader/__init__.py b/salt/loader/__init__.py
index 72a5e54401..32f8a7702c 100644
--- a/salt/loader/__init__.py
+++ b/salt/loader/__init__.py
@@ -9,6 +9,7 @@ import inspect
 import logging
 import os
 import re
+import threading
 import time
 import types
 
@@ -31,7 +32,7 @@ from salt.exceptions import LoaderError
 from salt.template import check_render_pipe_str
 from salt.utils import entrypoints
 
-from .lazy import SALT_BASE_PATH, FilterDictWrapper, LazyLoader
+from .lazy import SALT_BASE_PATH, FilterDictWrapper, LazyLoader as _LazyLoader
 
 log = logging.getLogger(__name__)
 
@@ -81,6 +82,18 @@ SALT_INTERNAL_LOADERS_PATHS = (
     str(SALT_BASE_PATH / "wheel"),
 )
 
+LOAD_LOCK = threading.Lock()
+
+
+def LazyLoader(*args, **kwargs):
+    # This wrapper is used to prevent deadlocks with importlib (bsc#1182851)
+    # LOAD_LOCK is also used directly in salt.client.ssh.SSH
+    try:
+        LOAD_LOCK.acquire()
+        return _LazyLoader(*args, **kwargs)
+    finally:
+        LOAD_LOCK.release()
+
 
 def static_loader(
     opts,
@@ -725,7 +738,7 @@ def fileserver(opts, backends, loaded_base_name=None):
     )
 
 
-def roster(opts, runner=None, utils=None, whitelist=None, loaded_base_name=None):
+def roster(opts, runner=None, utils=None, whitelist=None, loaded_base_name=None, context=None):
     """
     Returns the roster modules
 
@@ -736,12 +749,15 @@ def roster(opts, runner=None, utils=None, whitelist=None, loaded_base_name=None)
     :param str loaded_base_name: The imported modules namespace when imported
                                  by the salt loader.
     """
+    if context is None:
+        context = {}
+
     return LazyLoader(
         _module_dirs(opts, "roster"),
         opts,
         tag="roster",
         whitelist=whitelist,
-        pack={"__runner__": runner, "__utils__": utils},
+        pack={"__runner__": runner, "__utils__": utils, "__context__": context},
         extra_module_dirs=utils.module_dirs if utils else None,
         loaded_base_name=loaded_base_name,
     )
@@ -933,7 +949,14 @@ def render(
     )
     rend = FilterDictWrapper(ret, ".render")
 
-    if not check_render_pipe_str(
+    def _check_render_pipe_str(pipestr, renderers, blacklist, whitelist):
+        try:
+            LOAD_LOCK.acquire()
+            return check_render_pipe_str(pipestr, renderers, blacklist, whitelist)
+        finally:
+            LOAD_LOCK.release()
+
+    if not _check_render_pipe_str(
         opts["renderer"], rend, opts["renderer_blacklist"], opts["renderer_whitelist"]
     ):
         err = (
diff --git a/salt/netapi/__init__.py b/salt/netapi/__init__.py
index a89c1a19af..8a28c48460 100644
--- a/salt/netapi/__init__.py
+++ b/salt/netapi/__init__.py
@@ -79,6 +79,7 @@ class NetapiClient:
         self.loadauth = salt.auth.LoadAuth(apiopts)
         self.key = salt.daemons.masterapi.access_keys(apiopts)
         self.ckminions = salt.utils.minions.CkMinions(apiopts)
+        self.context = {}
 
     def _is_master_running(self):
         """
@@ -245,7 +246,7 @@ class NetapiClient:
         with salt.client.ssh.client.SSHClient(
             mopts=self.opts, disable_custom_roster=True
         ) as client:
-            return client.cmd_sync(kwargs)
+            return client.cmd_sync(kwargs, context=self.context)
 
     def runner(self, fun, timeout=None, full_return=False, **kwargs):
         """
diff --git a/salt/roster/__init__.py b/salt/roster/__init__.py
index fc7339d785..ea23d550d7 100644
--- a/salt/roster/__init__.py
+++ b/salt/roster/__init__.py
@@ -59,7 +59,7 @@ class Roster:
     minion aware
     """
 
-    def __init__(self, opts, backends="flat"):
+    def __init__(self, opts, backends="flat", context=None):
         self.opts = opts
         if isinstance(backends, list):
             self.backends = backends
@@ -71,7 +71,9 @@ class Roster:
             self.backends = ["flat"]
         utils = salt.loader.utils(self.opts)
         runner = salt.loader.runner(self.opts, utils=utils)
-        self.rosters = salt.loader.roster(self.opts, runner=runner, utils=utils)
+        self.rosters = salt.loader.roster(
+            self.opts, runner=runner, utils=utils, context=context
+        )
 
     def _gen_back(self):
         """
diff --git a/tests/unit/test_loader.py b/tests/unit/test_loader.py
index cf33903320..1b616375b3 100644
--- a/tests/unit/test_loader.py
+++ b/tests/unit/test_loader.py
@@ -1697,7 +1697,7 @@ class LazyLoaderRefreshFileMappingTest(TestCase):
         cls.funcs = salt.loader.minion_mods(cls.opts, utils=cls.utils, proxy=cls.proxy)
 
     def setUp(self):
-        class LazyLoaderMock(salt.loader.LazyLoader):
+        class LazyLoaderMock(salt.loader._LazyLoader):
             pass
 
         self.LOADER_CLASS = LazyLoaderMock
-- 
2.39.2