[ZTP] Use config db instead of ZTP configuration profile

By adding USE_DEFAULT_CONFIG="no" in /etc/default/ztp, it won't generate
/tmp/ztp_config_db.json, but using current redis config db during dhcp
discovery.

It will solve the breakout config reset to default mode issue.

==
[ZTP] Use config db for connectivity when process ZTP Json

When process ztp json, it will call loadZTPProfile("resume"),
which will also reset breakout config default mode.
Skip it when use_config_db.

src/etc/default/ztp

@@ -18,3 +18,6 @@ COVERAGE=""
 # Change below to provide command coverage.py tool.
 # (python3-coverage run --append is used if not specified)
 COVERAGE_CMD=""
+
+# Use ZTP configuration profile (default) or config_db
+USE_DEFAULT_CONFIG="yes"

src/usr/lib/ztp/sonic-ztp

@@ -37,6 +37,10 @@ start()
     # Custom ztp_cfg.json file
     [ "${CONFIG_JSON}" != "" ] && CONFIG_JSON_ARGS="-C ${CONFIG_JSON}"
 
+    # Use ZTP configuration profile (default) or config_db
+    [ "${USE_DEFAULT_CONFIG}" = "no" ] && CONFIG_DB_ARGS="-o"
+
+
     if [ "${COVERAGE}" = "yes" ]; then
         if which python3-coverage > /dev/null; then
             [ "${COVERAGE_CMD}" = "" ] && COVERAGE_EXP="python3-coverage run --append"
@@ -49,7 +53,7 @@ start()
     fi
 
     # Kickstart ZTP service daemon
-    ${COVERAGE_EXP} ${ZTP_ENGINE} ${DEBUG_ARGS} ${TEST_ARGS} ${CONFIG_JSON_ARGS} &
+    ${COVERAGE_EXP} ${ZTP_ENGINE} ${DEBUG_ARGS} ${TEST_ARGS} ${CONFIG_JSON_ARGS} ${CONFIG_DB_ARGS}&
 
     ztp_engine_pid=$!
     wait "$ztp_engine_pid"

src/usr/lib/ztp/ztp-engine.py

@@ -202,7 +202,7 @@ def __is_ztp_profile_active(self):
                     profile_active = True
         return profile_active
 
-    def __link_scan(self):
+    def __link_scan(self, use_config_db):
         '''!
         Scan all in-band interface's operational status to detect a link up event
            @return  False - If a link scan did not detect at least one switch port link up event
@@ -217,15 +217,17 @@ def __link_scan(self):
             self.__link_scan_enabled = None
             return False
 
-        if self.__link_scan_enabled is None:
-            # Check if ZTP configuration is active
-            if self.__is_ztp_profile_active():
-                self.__link_scan_enabled = 'True'
-            else:
-                self.__link_scan_enabled = 'False'
+        if (not use_config_db) :
 
-        if self.__link_scan_enabled == 'False':
-            return False
+            if self.__link_scan_enabled is None:
+                # Check if ZTP configuration is active
+                if self.__is_ztp_profile_active():
+                    self.__link_scan_enabled = 'True'
+                else:
+                    self.__link_scan_enabled = 'False'
+
+            if self.__link_scan_enabled == 'False':
+                return False
 
         # Populate data of all ztp eligible interfaces
         link_scan_result = self.__detect_intf_state()
@@ -303,6 +305,15 @@ def __loadZTPProfile(self, event):
             return True
         return False
 
+    def __discoverOnly(self):
+        # Do not attempt to install ZTP configuration if working in unit test mode
+        if self.test_mode:
+            return False
+
+        cmd = getCfg('ztp-lib-dir')+'/ztp-profile.sh discoverOnly'
+        rc = runCommand(cmd, capture_stdout=False)
+        return True
+
     def __createProvScriptJson(self):
         '''!
          Create ZTP JSON data to execute provisioning script specified by DHCP Option 239 URL.
@@ -545,7 +556,7 @@ def __processConfigSections(self):
                 # Check reboot on result flags
                 self.__rebootAction(section)
 
-    def __processZTPJson(self):
+    def __processZTPJson(self, use_config_db):
         '''!
          Process ZTP JSON file downloaded using URL provided by DHCP Option 67, DHCPv6 Option 59 or
          local ZTP JSON file.
@@ -601,8 +612,9 @@ def __processZTPJson(self):
 
         logger.info('Starting ZTP using JSON file %s at %s.' % (self.json_src, self.objztpJson['timestamp']))
 
-        # Initialize connectivity if not done already
-        self.__loadZTPProfile("resume")
+        if (not use_config_db):
+            # Initialize connectivity if not done already
+            self.__loadZTPProfile("resume")
 
         # Process available configuration sections in ZTP JSON
         self.__processConfigSections()
@@ -795,11 +807,12 @@ def __forceRestartDiscovery(self, msg):
         # Restart link-scan
         self.__intf_state = dict()
 
-    def executeLoop(self, test_mode=False):
+    def executeLoop(self, test_mode=False, use_config_db = False):
         '''!
          ZTP service loop which peforms provisioning data discovery and initiates processing.
         '''
-
+        if (use_config_db == True):
+            logger.info('use config db...')
         updateActivity('Initializing')
 
         # Set testing mode
@@ -838,26 +851,29 @@ def executeLoop(self, test_mode=False):
                     logger.debug('    ' + str(l[3]))
                 self.__forceRestartDiscovery("Invalid provisioning data received")
                 continue
-                                 
+
             if result:
                 if self.ztp_mode == 'MANUAL_CONFIG':
                     logger.info("Configuration file '%s' detected. Shutting down ZTP service." % (getCfg('config-db-json')))
                     break
                 elif self.ztp_mode != 'DISCOVERY':
-                    (rv, msg) = self.__processZTPJson()
+                    (rv, msg) = self.__processZTPJson(use_config_db)
                     if rv == "retry":
                         self.ztp_mode = 'DISCOVERY'
                     elif rv == "restart":
                         self.__forceRestartDiscovery(msg)
                     else:
                         break
-
-            # Initialize in-band interfaces to establish connectivity if not done already
-            self.__loadZTPProfile("discovery")
-            logger.debug('Provisioning data not found.')
+            if (not use_config_db):
+                # Initialize in-band interfaces to establish connectivity if not done already
+                self.__loadZTPProfile("discovery")
+                logger.debug('Provisioning data not found.')
+            else:
+                logger.debug('calling __discoverOnly...')
+                self.__discoverOnly()
 
             # Scan for inband interfaces to link up and restart interface connectivity
-            if self.__link_scan():
+            if self.__link_scan(use_config_db):
                 updateActivity('Restarting network discovery after link scan')
                 logger.info('Restarting network discovery after link scan.')
                 runCommand('systemctl restart interfaces-config', capture_stdout=False)
@@ -905,6 +921,7 @@ def main():
     parser.add_argument("-d", "--debug", action="store_true", help="Turn on debug level logging")
     parser.add_argument("-t", "--test", action="store_true", default=False, help="Start service in test mode with restricted functionality")
     parser.add_argument("-C", "--config-json", metavar='FILE', default=None, help="ZTP service configuration file")
+    parser.add_argument("-o", "--use-config-db", action="store_true", default=False, help="Use current config_db, don't install ztp_config")
 
     # Parse provided arguments
     options = parser.parse_args()
@@ -920,6 +937,11 @@ def main():
     else:
         _test_mode = False
 
+    if options.use_config_db:
+        _use_config_db = True
+    else:
+        _use_config_db = False
+
     # Parse user provided configuration file
     cfg_json = options.config_json
 
@@ -967,7 +989,7 @@ def main():
     objEngine = ZTPEngine()
 
     # Run ZTP service to completion
-    objEngine.executeLoop(_test_mode)
+    objEngine.executeLoop(_test_mode, _use_config_db)
 
     sys.exit(0)
 

src/usr/lib/ztp/ztp-profile.sh

@@ -229,6 +229,34 @@ if [ "$CMD" = "install" ] ; then
     fi
 fi
 
+if [ "$CMD" = "discoverOnly" ] ; then
+    echo "System is discoverOnly"
+    # setup rsyslog forwarding
+    touch ${SYSLOG_CONF_FILE}
+    if [ "$(get_feature console-logging)" = "true" ]; then
+        echo ":programname, contains, \"sonic-ztp\"  /dev/console" > ${SYSLOG_CONSOLE_CONF_FILE}
+    fi
+    systemctl restart rsyslog
+
+    #setup db
+    sonic-db-cli CONFIG_DB HSET "ZTP|mode" "inband" "true"
+    sonic-db-cli CONFIG_DB HSET "ZTP|mode" "out-of-band" "true"
+    sonic-db-cli CONFIG_DB HSET "ZTP|mode" "ipv4" "true"
+    sonic-db-cli CONFIG_DB HSET "ZTP|mode" "ipv6" "true"
+
+    ln -sf /usr/lib/ztp/dhcp/ztp-rsyslog /etc/dhcp/dhclient-exit-hooks.d/ztp-rsyslog
+    echo "Initiating ZTP discovery."
+
+
+    # Install DHCP policy for interfaces participating in ZTP
+    dhcp_policy_create
+    echo "Restarting network configuration."
+    updateActivity "Restarting network configuration"
+    systemctl restart interfaces-config
+    echo "Restarted network configuration."
+
+fi
+
 # Process ZTP profile remove request
 if [ "$CMD" = "remove" ] ; then