[reboot-history] Add reboot history to state db (#5933)

- Why I did it
Add reboot history to State db so that can be used telemetry service
- How I did it
Split the process-reboot-cause service to determine-reboot-cause and process-reboot-cause
determine-reboot-cause to determine the reboot cause
process-reboot-cause to parse the reboot cause files and put the reboot history to state db
Moved to sonic-host-service* packages
- How to verify it
Performed unit test and tested on DUT

files/build_templates/sonic_debian_extension.j2

@@ -428,16 +428,6 @@ sudo cp $IMAGE_CONFIGS/pcie-check/pcie-check.service $FILESYSTEM_ROOT_USR_LIB_SY
 echo "pcie-check.service" | sudo tee -a $GENERATED_SERVICE_FILE
 sudo cp $IMAGE_CONFIGS/pcie-check/pcie-check.sh $FILESYSTEM_ROOT/usr/bin/
 
-# Copy systemd timer configuration
-# It implements delayed start of services
-sudo cp $BUILD_TEMPLATES/process-reboot-cause.timer $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM
-sudo LANG=C chroot $FILESYSTEM_ROOT systemctl enable process-reboot-cause.timer
-
-# Copy process-reboot-cause service files
-sudo cp $IMAGE_CONFIGS/process-reboot-cause/process-reboot-cause.service $FILESYSTEM_ROOT_USR_LIB_SYSTEMD_SYSTEM
-echo "process-reboot-cause.service" | sudo tee -a $GENERATED_SERVICE_FILE
-sudo cp $IMAGE_CONFIGS/process-reboot-cause/process-reboot-cause $FILESYSTEM_ROOT/usr/bin/
-
 ## Install package without starting service
 ## ref: https://wiki.debian.org/chroot
 sudo tee -a $FILESYSTEM_ROOT/usr/sbin/policy-rc.d > /dev/null <<EOF

src/sonic-host-services-data/debian/rules

@@ -9,3 +9,6 @@ override_dh_installsystemd:
 	dh_installsystemd --no-start --name=caclmgrd
 	dh_installsystemd --no-start --name=hostcfgd
 	dh_installsystemd --no-start --name=procdockerstatsd
+	dh_installsystemd --no-start --name=determine-reboot-cause
+	dh_installsystemd --no-start --name=process-reboot-cause
+

src/sonic-host-services-data/debian/sonic-host-services-data.determine-reboot-cause.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Reboot cause determination service
+Requires=rc-local.service
+After=rc-local.service
+
+[Service]
+Type=simple
+ExecStart=/usr/local/bin/determine-reboot-cause
+
+[Install]
+WantedBy=multi-user.target

src/sonic-host-services/scripts/determine-reboot-cause

@@ -1,28 +1,32 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 #
-# process-reboot-cause
+# determine-reboot-cause
 #
 # Program designed to run once, soon after system boot which will
 # determine the cause of the previous reboot and store it to the disk,
 #
 
 try:
+    import datetime
+    import json
     import os
     import pwd
     import re
     import sys
 
     from sonic_py_common import device_info, logger
+
 except ImportError as err:
     raise ImportError("%s - required module not found" % str(err))
 
 VERSION = "1.0"
 
-SYSLOG_IDENTIFIER = "process-reboot-cause"
+SYSLOG_IDENTIFIER = "determine-reboot-cause"
 
 REBOOT_CAUSE_DIR = "/host/reboot-cause/"
-REBOOT_CAUSE_FILE = REBOOT_CAUSE_DIR + "reboot-cause.txt"
+REBOOT_CAUSE_HISTORY_DIR = "/host/reboot-cause/history/"
-PREVIOUS_REBOOT_CAUSE_FILE = REBOOT_CAUSE_DIR + "previous-reboot-cause.txt"
+REBOOT_CAUSE_FILE = os.path.join(REBOOT_CAUSE_DIR, "reboot-cause.txt")
+PREVIOUS_REBOOT_CAUSE_FILE = os.path.join(REBOOT_CAUSE_DIR,  "previous-reboot-cause.json")
 FIRST_BOOT_PLATFORM_FILE = "/tmp/notify_firstboot_to_platform"
 REBOOT_TYPE_KEXEC_FILE = "/proc/cmdline"
 # The following SONIC_BOOT_TYPEs come from the warm/fast reboot script which is in sonic-utilities
@@ -45,7 +49,7 @@ sonic_logger = logger.Logger(SYSLOG_IDENTIFIER)
 # ============================= Functions =============================
 def parse_warmfast_reboot_from_proc_cmdline():
     if os.path.isfile(REBOOT_TYPE_KEXEC_FILE):
-        with open(REBOOT_TYPE_KEXEC_FILE, "r") as cause_file:
+        with open(REBOOT_TYPE_KEXEC_FILE) as cause_file:
             cause_file_kexec = cause_file.readline()
         m = re.search(REBOOT_TYPE_KEXEC_PATTERN_WARM, cause_file_kexec)
         if m and m.group(1):
@@ -56,69 +60,100 @@ def parse_warmfast_reboot_from_proc_cmdline():
     return None
 
 
-def find_software_reboot_cause():
+def find_software_reboot_cause_from_reboot_cause_file():
-    software_reboot_cause = REBOOT_CAUSE_UNKNOWN
+    software_reboot_cause = None
-
     if os.path.isfile(REBOOT_CAUSE_FILE):
-        with open(REBOOT_CAUSE_FILE, "r") as cause_file:
+        with open(REBOOT_CAUSE_FILE) as cause_file:
             software_reboot_cause = cause_file.readline().rstrip('\n')
             sonic_logger.log_info("{} indicates the reboot cause: {}".format(REBOOT_CAUSE_FILE, software_reboot_cause))
     else:
         sonic_logger.log_info("Reboot cause file {} not found".format(REBOOT_CAUSE_FILE))
+    return software_reboot_cause
 
-    if os.path.isfile(FIRST_BOOT_PLATFORM_FILE):
-        if software_reboot_cause == REBOOT_CAUSE_UNKNOWN:
-            version_info = device_info.get_sonic_version_info()
-            build_version = version_info['build_version'] if version_info else "unknown"
-            software_reboot_cause += " (First boot of SONiC version {})".format(build_version)
-        os.remove(FIRST_BOOT_PLATFORM_FILE)
 
+def find_first_boot_version():
+    build_version = "unknown"
+    version_info = device_info.get_sonic_version_info()
+    if version_info:
+        build_version = version_info['build_version']
+    return " (First boot of SONiC version {})".format(build_version)
+
+
+def find_software_reboot_cause():
+    software_reboot_cause = find_software_reboot_cause_from_reboot_cause_file()
+    if software_reboot_cause == REBOOT_CAUSE_UNKNOWN:
+        if os.path.isfile(FIRST_BOOT_PLATFORM_FILE):
+            software_reboot_cause += find_first_boot_version()
+            os.remove(FIRST_BOOT_PLATFORM_FILE)
     return software_reboot_cause
 
 
 def find_proc_cmdline_reboot_cause():
     proc_cmdline_reboot_cause = parse_warmfast_reboot_from_proc_cmdline()
- 
+
     if proc_cmdline_reboot_cause:
         sonic_logger.log_info("/proc/cmdline indicates reboot type: {}".format(proc_cmdline_reboot_cause))
     else:
         sonic_logger.log_info("No reboot cause found from /proc/cmdline")
- 
+
     return proc_cmdline_reboot_cause
- 
-
-def find_hardware_reboot_cause():
-    hardware_reboot_cause = None
 
+def get_reboot_cause_from_platform():
     # Until all platform vendors have provided sonic_platform packages,
     # if there is no sonic_platform package installed, we only provide
     # software-related reboot causes.
     try:
         import sonic_platform
-
+        platform  = sonic_platform.platform.Platform()
-        platform = sonic_platform.platform.Platform()
+        chassis  = platform.get_chassis()
-
+        return chassis.get_reboot_cause()
-        chassis = platform.get_chassis()
-
-        hardware_reboot_cause_major, hardware_reboot_cause_minor = chassis.get_reboot_cause()
-
-        if hardware_reboot_cause_major == chassis.REBOOT_CAUSE_NON_HARDWARE:
-            # The reboot was not caused by hardware. If there is a REBOOT_CAUSE_FILE, it will
-            # contain any software-related reboot info. We will use it as the previous cause.
-            pass
-        elif hardware_reboot_cause_major == chassis.REBOOT_CAUSE_HARDWARE_OTHER:
-            hardware_reboot_cause = "{} ({})".format(hardware_reboot_cause_major, hardware_reboot_cause_minor)
-        else:
-            hardware_reboot_cause = hardware_reboot_cause_major
     except ImportError as err:
         sonic_logger.log_warning("sonic_platform package not installed. Unable to detect hardware reboot causes.")
 
+
+def find_hardware_reboot_cause():
+    hardware_reboot_cause = None
+
+    REBOOT_CAUSE_HARDWARE_OTHER = "Hardware - Other"
+    REBOOT_CAUSE_NON_HARDWARE = "Non-Hardware"
+
+    hardware_reboot_cause_major, hardware_reboot_cause_minor = get_reboot_cause_from_platform()
+    sonic_logger.log_info("Platform api returns reboot cause {}, {}".format(hardware_reboot_cause_major, hardware_reboot_cause_minor))
+
+    if hardware_reboot_cause_major == REBOOT_CAUSE_NON_HARDWARE:
+        # The reboot was not caused by hardware. If there is a REBOOT_CAUSE_FILE, it will
+        # contain any software-related reboot info. We will use it as the previous cause.
+        pass
+    elif hardware_reboot_cause_major == REBOOT_CAUSE_HARDWARE_OTHER:
+        hardware_reboot_cause = "{} ({})".format(hardware_reboot_cause_major, hardware_reboot_cause_minor)
+    else:
+        hardware_reboot_cause = hardware_reboot_cause_major
+
     if hardware_reboot_cause:
         sonic_logger.log_info("Platform api indicates reboot cause {}".format(hardware_reboot_cause))
     else:
         sonic_logger.log_info("No reboot cause found from platform api")
 
-    return hardware_reboot_cause
+    return hardware_reboot_cause, hardware_reboot_cause_minor
+
+def get_reboot_cause_dict(previous_reboot_cause, comment, gen_time):
+    # resultant dictionary
+    reboot_cause_dict = {}
+    reboot_cause_dict['gen_time'] = gen_time
+    reboot_cause_dict['cause'] = previous_reboot_cause
+    reboot_cause_dict['user'] = "N/A"
+    reboot_cause_dict['time'] = "N/A"
+    reboot_cause_dict['comment'] = comment if comment is not None else "N/A"
+
+    if re.search(r'User issued', previous_reboot_cause):
+        # Match with "User issued '{}' command [User: {}, Time: {}]"
+        match = re.search(r'User issued \'(.*)\' command \[User: (.*), Time: (.*)\]', previous_reboot_cause)
+        if match is not None:
+            reboot_cause_dict['cause'] = match.group(1)
+            reboot_cause_dict['user'] = match.group(2)
+            reboot_cause_dict['time'] = match.group(3)
+
+    return reboot_cause_dict
 
 
 def main():
@@ -139,15 +174,15 @@ def main():
     if os.path.exists(PREVIOUS_REBOOT_CAUSE_FILE):
         os.remove(PREVIOUS_REBOOT_CAUSE_FILE)
 
-    # Set a default previous reboot cause
+    hardware_reboot_cause = None
-    previous_reboot_cause = REBOOT_CAUSE_UNKNOWN
+    additional_reboot_info = None
 
     # 1. Check if the previous reboot was warm/fast reboot by testing whether there is "fast|fastfast|warm" in /proc/cmdline
     proc_cmdline_reboot_cause = find_proc_cmdline_reboot_cause()
 
     # 2. Check if the previous reboot was caused by hardware
     #    If yes, the hardware reboot cause will be treated as the reboot cause
-    hardware_reboot_cause = find_hardware_reboot_cause()
+    (hardware_reboot_cause, additional_reboot_info) = find_hardware_reboot_cause()
 
     # 3. If there is a REBOOT_CAUSE_FILE, it will contain any software-related
     #    reboot info. We will use it as the previous cause.
@@ -155,7 +190,7 @@ def main():
 
     # The main decision logic of the reboot cause:
     # If there is a reboot cause indicated by /proc/cmdline, it should be warmreboot/fastreboot
-    #   the software_reboot_cause which is the content of /hosts/reboot-cause/reboot-cause.txt 
+    #   the software_reboot_cause which is the content of /hosts/reboot-cause/reboot-cause.txt
     #   will be treated as the reboot cause
     # Elif there is a reboot cause indicated by platform API,
     #   the hardware_reboot_cause will be treated as the reboot cause
@@ -167,12 +202,26 @@ def main():
     else:
         previous_reboot_cause = software_reboot_cause
 
-    # Write the previous reboot cause to PREVIOUS_REBOOT_CAUSE_FILE
+    # Current time
-    with open(PREVIOUS_REBOOT_CAUSE_FILE, "w") as prev_cause_file:
+    reboot_cause_gen_time = str(datetime.datetime.now().strftime('%Y_%m_%d_%H_%M_%S'))
-        prev_cause_file.write(previous_reboot_cause)
+
+    # Save the previous cause info into its history file as json format
+    reboot_cause_dict = get_reboot_cause_dict(previous_reboot_cause, additional_reboot_info, reboot_cause_gen_time)
+
+    # Create reboot-cause-#time#.json under history directory
+    REBOOT_CAUSE_HISTORY_FILE = os.path.join(REBOOT_CAUSE_HISTORY_DIR, "reboot-cause-{}.json".format(reboot_cause_gen_time))
+
+    # Create REBOOT_CAUSE_HISTORY_DIR if it doesn't exist
+    if not os.path.exists(REBOOT_CAUSE_HISTORY_DIR):
+        os.makedirs(REBOOT_CAUSE_HISTORY_DIR)
+
+    # Write the previous reboot cause to REBOOT_CAUSE_HISTORY_FILE as a JSON format
+    with open(REBOOT_CAUSE_HISTORY_FILE, "w") as reboot_cause_history_file:
+        json.dump(reboot_cause_dict, reboot_cause_history_file)
+
+    # Create a symbolic link to previous-reboot-cause.json file
+    os.symlink(REBOOT_CAUSE_HISTORY_FILE, PREVIOUS_REBOOT_CAUSE_FILE)
 
-    # Also log the previous reboot cause to the syslog
-    sonic_logger.log_info("Previous reboot cause: {}".format(previous_reboot_cause))
 
     # Remove the old REBOOT_CAUSE_FILE
     if os.path.exists(REBOOT_CAUSE_FILE):

src/sonic-host-services/scripts/process-reboot-cause

@@ -0,0 +1,100 @@
+#!/usr/bin/env python3
+#
+# process-reboot-cause
+#
+# Program designed to read the previous reboot-cause files, log the last previous reboot-cause.
+# And read the saved reboot-cause history files and save the reboot cause in the state-db.
+#
+
+try:
+    import json
+    import os
+    import pwd
+    import sys
+
+    import swsssdk
+    from sonic_py_common import logger
+except ImportError as err:
+    raise ImportError("%s - required module not found" % str(err))
+
+VERSION = "1.0"
+
+SYSLOG_IDENTIFIER = "process-reboot-cause"
+
+REBOOT_CAUSE_DIR = "/host/reboot-cause/"
+REBOOT_CAUSE_HISTORY_DIR = "/host/reboot-cause/history/"
+PREVIOUS_REBOOT_CAUSE_FILE = os.path.join(REBOOT_CAUSE_DIR, "previous-reboot-cause.json")
+USER_ISSUED_REBOOT_CAUSE_REGEX ="User issued \'{}\' command [User: {}, Time: {}]"
+
+REBOOT_CAUSE_UNKNOWN = "Unknown"
+REBOOT_CAUSE_TABLE_NAME = "REBOOT_CAUSE"
+
+REDIS_HOSTIP = "127.0.0.1"
+state_db = None
+
+# Global logger class instance
+sonic_logger = logger.Logger(SYSLOG_IDENTIFIER)
+
+
+# ============================= Functions =============================
+def read_reboot_cause_files_and_save_state_db():
+    # Connect State DB
+    state_db = swsssdk.SonicV2Connector(host=REDIS_HOSTIP)
+    state_db.connect(state_db.STATE_DB)
+
+    # Sort the previous reboot cause files by creation time
+    REBOOT_FILE_LIST = [os.path.join(REBOOT_CAUSE_HISTORY_DIR, i) for i in os.listdir(REBOOT_CAUSE_HISTORY_DIR)]
+    TIME_SORTED_FULL_REBOOT_FILE_LIST = sorted(REBOOT_FILE_LIST, key=os.path.getmtime, reverse=True)
+
+    data = []
+    # Read each sorted previous reboot cause file and update the state db with previous reboot cause information
+    for i in range(min(10, len(TIME_SORTED_FULL_REBOOT_FILE_LIST))):
+        x = TIME_SORTED_FULL_REBOOT_FILE_LIST[i]
+        if os.path.isfile(x):
+            with open(x, "r") as cause_file:
+                data = json.load(cause_file)
+                _hash = '{}|{}'.format(REBOOT_CAUSE_TABLE_NAME, data['gen_time'])
+                state_db.set(state_db.STATE_DB, _hash, 'cause', data['cause'])
+                state_db.set(state_db.STATE_DB, _hash, 'time', data['time'])
+                state_db.set(state_db.STATE_DB, _hash, 'user', data['user'])
+                state_db.set(state_db.STATE_DB, _hash, 'comment', data['comment'])
+
+    if len(TIME_SORTED_FULL_REBOOT_FILE_LIST) > 10:
+        for i in range(len(TIME_SORTED_FULL_REBOOT_FILE_LIST)):
+            if i >= 10:
+                x = TIME_SORTED_FULL_REBOOT_FILE_LIST[i]
+                os.remove(x)
+
+
+def main():
+    # Configure logger to log all messages INFO level and higher
+    sonic_logger.set_min_log_priority_info()
+
+    sonic_logger.log_info("Starting up...")
+
+    if not os.geteuid() == 0:
+        sonic_logger.log_error("User {} does not have permission to execute".format(pwd.getpwuid(os.getuid()).pw_name))
+        sys.exit("This utility must be run as root")
+
+    # Set a default previous reboot cause
+    previous_reboot_cause = REBOOT_CAUSE_UNKNOWN
+
+    # Read the most recent reboot cause file and log data to syslog
+    if os.path.exists(PREVIOUS_REBOOT_CAUSE_FILE):
+        with open(PREVIOUS_REBOOT_CAUSE_FILE, "r") as last_cause_file:
+            data = json.load(last_cause_file)
+            if data['user']:
+                previous_reboot_cause = USER_ISSUED_REBOOT_CAUSE_REGEX.format(data['cause'], data['user'], data['time'])
+            else:
+                previous_reboot_cause = "{}".format(data['cause'])
+
+    # Log the last reboot cause to the syslog
+    sonic_logger.log_info("Previous reboot cause: {}".format(previous_reboot_cause))
+
+    if os.path.exists(REBOOT_CAUSE_HISTORY_DIR):
+        # Read the previous reboot cause from saved reboot-cause files and save the previous reboot cause upto 10 entry to the state db
+        read_reboot_cause_files_and_save_state_db()
+
+
+if __name__ == "__main__":
+    main()

src/sonic-host-services/setup.py

@@ -14,6 +14,8 @@ setup(
         'scripts/caclmgrd',
         'scripts/hostcfgd',
         'scripts/procdockerstatsd',
+        'scripts/determine-reboot-cause',
+        'scripts/process-reboot-cause',
     ],
     install_requires = [
         'Jinja2>=2.10',

src/sonic-host-services/tests/determine-reboot-cause_test.py

@@ -0,0 +1,117 @@
+import imp
+import sys
+import os
+import pytest
+
+import swsssdk
+
+# TODO: Remove this if/else block once we no longer support Python 2
+if sys.version_info.major == 3:
+    from unittest import mock
+else:
+    # Expect the 'mock' package for python 2
+    # https://pypi.python.org/pypi/mock
+    import mock
+
+# TODO: Remove this if/else block once we no longer support Python 2
+if sys.version_info.major == 3:
+    BUILTINS = "builtins"
+else:
+    BUILTINS = "__builtin__"
+
+from .mock_connector import MockConnector
+
+swsssdk.SonicV2Connector = MockConnector
+
+test_path = os.path.dirname(os.path.abspath(__file__))
+modules_path = os.path.dirname(test_path)
+scripts_path = os.path.join(modules_path, "scripts")
+sys.path.insert(0, modules_path)
+
+PROC_CMDLINE_CONTENTS = """\
+BOOT_IMAGE=/image-20191130.52/boot/vmlinuz-4.9.0-11-2-amd64 root=/dev/sda4 rw console=tty0 console=ttyS1,9600n8 quiet net.ifnames=0 biosdevname=0 loop=image-20191130.52/fs.squashfs loopfstype=squashfs apparmor=1 security=apparmor varlog_size=4096 usbcore.autosuspend=-1 module_blacklist=gpio_ich SONIC_BOOT_TYPE=warm"""
+
+EXPECTED_PARSE_WARMFAST_REBOOT_FROM_PROC_CMDLINE = "warm"
+
+PROC_CMDLINE_CONTENTS = """\
+BOOT_IMAGE=/image-20191130.52/boot/vmlinuz-4.9.0-11-2-amd64 root=/dev/sda4 rw console=tty0 console=ttyS1,9600n8 quiet net.ifnames=0 biosdevname=0 loop=image-20191130.52/fs.squashfs loopfstype=squashfs apparmor=1 security=apparmor varlog_size=4096 usbcore.autosuspend=-1 module_blacklist=gpio_ich SONIC_BOOT_TYPE=warm"""
+
+REBOOT_CAUSE_CONTENTS = """\
+User issued 'warm-reboot' command [User: admin, Time: Mon Nov  2 22:37:45 UTC 2020]""" 
+
+GET_SONIC_VERSION_INFO = {'commit_id': 'e59ec8291', 'build_date': 'Mon Nov  2 06:00:14 UTC 2020', 'build_number': 75, 'kernel_version': '4.9.0-11-2-amd64', 'debian_version': '9.13', 'built_by': 'sonicbld@jenkins-slave-phx-2', 'asic_type': 'mellanox', 'build_version': '20191130.52'} 
+
+REBOOT_CAUSE_WATCHDOG = "Watchdog"
+GEN_TIME_WATCHDOG = "2020_10_22_03_15_08"
+REBOOT_CAUSE_USER = "User issued 'reboot' command [User: admin, Time: Thu Oct 22 03:11:08 UTC 2020]"
+GEN_TIME_USER = "2020_10_22_03_14_07"
+
+EXPECTED_PARSE_WARMFAST_REBOOT_FROM_PROC_CMDLINE = "warm-reboot"
+EXPECTED_FIND_SOFTWARE_REBOOT_CAUSE_USER = "User issued 'warm-reboot' command [User: admin, Time: Mon Nov  2 22:37:45 UTC 2020]"
+EXPECTED_FIND_FIRSTBOOT_VERSION = " (First boot of SONiC version 20191130.52)"
+EXPECTED_FIND_SOFTWARE_REBOOT_CAUSE_FIRSTBOOT = "Unknown (First boot of SONiC version 20191130.52)"
+EXPECTED_HARDWARE_REBOOT_CAUSE = {"warm-reboot", ""}
+
+EXPECTED_WATCHDOG_REBOOT_CAUSE_DICT = {'comment': '', 'gen_time': '2020_10_22_03_15_08', 'cause': 'Watchdog', 'user': 'N/A', 'time': 'N/A'}
+EXPECTED_USER_REBOOT_CAUSE_DICT = {'comment': '', 'gen_time': '2020_10_22_03_14_07', 'cause': 'reboot', 'user': 'admin', 'time': 'Thu Oct 22 03:11:08 UTC 2020'}
+
+imp.load_source('determine_reboot_cause', scripts_path + '/determine-reboot-cause')
+from determine_reboot_cause import *
+
+class TestDetermineRebootCause(object):
+    @classmethod
+    def setup_class(cls):
+        print("SETUP")
+
+    def test_parse_warmfast_reboot_from_proc_cmdline(self):
+        with mock.patch("os.path.isfile") as mock_isfile:
+            mock_isfile.return_value = True
+            open_mocked = mock.mock_open(read_data=PROC_CMDLINE_CONTENTS) 
+            with mock.patch("{}.open".format(BUILTINS), open_mocked): 
+                result = parse_warmfast_reboot_from_proc_cmdline() 
+                assert result == EXPECTED_PARSE_WARMFAST_REBOOT_FROM_PROC_CMDLINE
+                open_mocked.assert_called_once_with("/proc/cmdline") 
+
+    def test_find_software_reboot_cause_user(self):
+        with mock.patch("os.path.isfile") as mock_isfile: 
+            mock_isfile.return_value = True 
+            open_mocked = mock.mock_open(read_data=REBOOT_CAUSE_CONTENTS) 
+            with mock.patch("{}.open".format(BUILTINS), open_mocked): 
+                 result = find_software_reboot_cause_from_reboot_cause_file() 
+                 assert result == EXPECTED_FIND_SOFTWARE_REBOOT_CAUSE_USER
+                 open_mocked.assert_called_once_with("/host/reboot-cause/reboot-cause.txt") 
+
+    def test_find_software_reboot_cause_first_boot(self):
+        with mock.patch("sonic_py_common.device_info.get_sonic_version_info", return_value=GET_SONIC_VERSION_INFO):
+            result = find_first_boot_version() 
+            assert result == EXPECTED_FIND_FIRSTBOOT_VERSION
+
+    def test_find_software_reboot_cause(self):
+        with mock.patch("determine_reboot_cause.find_software_reboot_cause_from_reboot_cause_file", return_value="Unknown"):
+            with mock.patch("os.path.isfile") as mock_isfile: 
+                mock_isfile.return_value = False 
+                result = find_software_reboot_cause() 
+                assert result == "Unknown"
+
+    def test_find_proc_cmdline_reboot_cause(self):
+        with mock.patch("determine_reboot_cause.parse_warmfast_reboot_from_proc_cmdline", return_value="fast-reboot"):
+            result = find_proc_cmdline_reboot_cause() 
+            assert result == "fast-reboot"
+
+    def test_find_hardware_reboot_cause(self):
+        with mock.patch("determine_reboot_cause.get_reboot_cause_from_platform", return_value=("Powerloss", None)):
+            result = find_hardware_reboot_cause() 
+            assert result == ("Powerloss", None)
+
+    def test_get_reboot_cause_dict_watchdog(self):
+        reboot_cause_dict = get_reboot_cause_dict(REBOOT_CAUSE_WATCHDOG, "", GEN_TIME_WATCHDOG) 
+        assert reboot_cause_dict == EXPECTED_WATCHDOG_REBOOT_CAUSE_DICT
+
+    def test_get_reboot_cause_dict_user(self):
+        reboot_cause_dict = get_reboot_cause_dict(REBOOT_CAUSE_USER, "", GEN_TIME_USER) 
+        assert reboot_cause_dict == EXPECTED_USER_REBOOT_CAUSE_DICT
+
+    @classmethod
+    def teardown_class(cls):
+        print("TREARDOWN")
+