[techsupport] Handle minor fixes of TS Lock and update auto-TS (sonic-net#2114)

1. Print the last statement as the techsupport dump name, as some automation processes might depend of parsing the last line to infer the dump path.

Previously:
  handle_exit
  Removing lock. Exit: 0
  removed '/tmp/techsupport-lock/PID'
  removed directory '/tmp/techsupport-lock'

Updated:
  handle_exit
  Removing lock. Exit: 0
  removed '/tmp/techsupport-lock/PID'
  removed directory '/tmp/techsupport-lock'
  /var/dump/sonic_dump_r-bulldog-03_20220324_195553.tar.gz

2. Don't acquire the lock when running in NOOP mode
3. Set the set -v option just before running main so that it won't print the generate_dump code to stdout
4. Update the auto-techsupport script to handle EXT_RETRY and EXT_LOCKFAIL exit codes returned by show techsupport command.
5. Update the minor error in since argument for auto-techsupport

Signed-off-by: Vivek Keddy Karri <[email protected]>

Author: vivekrnv

scripts/coredump_gen_handler.py

@@ -110,18 +110,26 @@ def parse_ts_dump_name(self, ts_stdout):
         syslog.syslog(syslog.LOG_ERR, "stdout of the 'show techsupport' cmd doesn't have the dump name")
         return ""
 
-    def invoke_ts_cmd(self, since_cfg):
-        since_cfg = "'" + since_cfg + "'"
+    def invoke_ts_cmd(self, since_cfg, num_retry=0):
         cmd_opts = ["show", "techsupport", "--silent", "--since", since_cfg]
         cmd  = " ".join(cmd_opts)
         rc, stdout, stderr = subprocess_exec(cmd_opts, env=ENV_VAR)
-        if rc:
+        new_dump = ""
+        if rc == EXT_LOCKFAIL:
+            syslog.syslog(syslog.LOG_NOTICE, "Another instance of techsupport running, aborting this. stderr: {}".format(stderr))
+        elif rc == EXT_RETRY:
+            if num_retry <= MAX_RETRY_LIMIT:
+                return self.invoke_ts_cmd(since_cfg, num_retry+1)
+            else:
+                syslog.syslog(syslog.LOG_ERR, "MAX_RETRY_LIMIT for show techsupport invocation exceeded, stderr: {}".format(stderr))
+        elif rc != EXT_SUCCESS:
             syslog.syslog(syslog.LOG_ERR, "show techsupport failed with exit code {}, stderr: {}".format(rc, stderr))
-        new_dump = self.parse_ts_dump_name(stdout)
-        if not new_dump:
-            syslog.syslog(syslog.LOG_ERR, "{} was run, but no techsupport dump is found".format(cmd))
-        else:
-            syslog.syslog(syslog.LOG_INFO, "{} is successful, {} is created".format(cmd, new_dump))
+        else: # EXT_SUCCESS
+            new_dump = self.parse_ts_dump_name(stdout) # Parse the dump name
+            if not new_dump:
+                syslog.syslog(syslog.LOG_ERR, "{} was run, but no techsupport dump is found".format(cmd))
+            else:
+                syslog.syslog(syslog.LOG_INFO, "{} is successful, {} is created".format(cmd, new_dump))
         return new_dump
 
     def verify_rate_limit_intervals(self, global_cooloff, container_cooloff):

scripts/generate_dump

@@ -63,6 +63,10 @@ handle_exit()
     ECODE=$?
     echo "Removing lock. Exit: $ECODE" >&2
     $RM $V -rf ${LOCKDIR}
+    # Echo the filename as the last statement if the generation succeeds
+    if [[ -f $TARFILE && ($ECODE == $EXT_SUCCESS || $ECODE == $RETURN_CODE) ]]; then
+        echo $TARFILE
+    fi
 }
 
 handle_signal()
@@ -1360,8 +1364,6 @@ main() {
 
     # Invoke the TechSupport Cleanup Hook
     setsid python3 /usr/local/bin/techsupport_cleanup.py ${TARFILE} &> /tmp/techsupport_cleanup.log &
-
-    echo ${TARFILE}
 
     if ! $SAVE_STDERR
     then
@@ -1494,7 +1496,6 @@ while getopts ":xnvhzas:t:r:d" opt; do
             ;;
         v)
             # echo commands about to be run to stderr
-            set -v
             V="-v"
             ;;
         n)
@@ -1547,14 +1548,17 @@ fi
 ## Attempt Locking
 ##
 
-if mkdir "${LOCKDIR}" &>/dev/null; then
+if $MKDIR "${LOCKDIR}" &>/dev/null; then
     trap 'handle_exit' EXIT
     echo "$$" > "${PIDFILE}"
     # This handler will exit the script upon receiving these interrupts
     # Trap configured on EXIT will be triggered by the exit from handle_signal function
     trap 'handle_signal' SIGINT SIGHUP SIGQUIT SIGTERM
     echo "Lock succesfully accquired and installed signal handlers"
     # Proceed with the actual code
+    if [[ ! -z "${V}" ]]; then
+        set -v
+    fi
     main
 else
     # lock failed, check if the other PID is alive

tests/coredump_gen_handler_test.py

@@ -3,10 +3,12 @@
 import sys
 import pyfakefs
 import unittest
+import signal
 from pyfakefs.fake_filesystem_unittest import Patcher
 from swsscommon import swsscommon
 from utilities_common.general import load_module_from_source
 from utilities_common.db import Db
+from utilities_common.auto_techsupport_helper import EXT_RETRY
 from .mock_tables import dbconnector
 
 sys.path.append("scripts")
@@ -18,6 +20,9 @@
 /tmp/saisdkdump
 """
 
+def signal_handler(signum, frame):
+    raise Exception("Timed out!")
+
 def set_auto_ts_cfg(redis_mock, state="disabled",
                     rate_limit_interval="0",
                     max_core_size="0.0",
@@ -264,7 +269,7 @@ def test_since_argument(self):
             def mock_cmd(cmd, env):
                 ts_dump = "/var/dump/sonic_dump_random3.tar.gz"
                 cmd_str = " ".join(cmd)
-                if "--since '4 days ago'" in cmd_str:
+                if "--since 4 days ago" in cmd_str:
                     patcher.fs.create_file(ts_dump)
                     return 0, AUTO_TS_STDOUT + ts_dump, ""
                 elif "date --date=4 days ago" in cmd_str:
@@ -330,7 +335,7 @@ def test_invalid_since_argument(self):
             def mock_cmd(cmd, env):
                 ts_dump = "/var/dump/sonic_dump_random3.tar.gz"
                 cmd_str = " ".join(cmd)
-                if "--since '2 days ago'" in cmd_str:
+                if "--since 2 days ago" in cmd_str:
                     patcher.fs.create_file(ts_dump)
                     print(AUTO_TS_STDOUT + ts_dump)
                     return 0, AUTO_TS_STDOUT + ts_dump, ""
@@ -396,3 +401,30 @@ def mock_cmd(cmd, env):
             assert "orchagent.12345.123.core.gz" in current_fs
             assert "lldpmgrd.12345.22.core.gz" in current_fs
             assert "python3.12345.21.core.gz" in current_fs
+
+    def test_max_retry_ts_failure(self):
+        """
+        Scenario: TS subprocess is continously returning EXT_RETRY
+                  Make sure auto-ts is not exceeding the limit
+        """
+        db_wrap = Db()
+        redis_mock = db_wrap.db
+        set_auto_ts_cfg(redis_mock, state="enabled")
+        set_feature_table_cfg(redis_mock, state="enabled")
+        with Patcher() as patcher:
+            def mock_cmd(cmd, env):
+                return EXT_RETRY, "", ""
+
+            cdump_mod.subprocess_exec = mock_cmd
+            patcher.fs.create_file("/var/core/orchagent.12345.123.core.gz")
+            cls = cdump_mod.CriticalProcCoreDumpHandle("orchagent.12345.123.core.gz", "swss", redis_mock)
+        
+            signal.signal(signal.SIGALRM, signal_handler)
+            signal.alarm(5)   # 5 seconds
+            try:
+                cls.handle_core_dump_creation_event()
+            except Exception:
+                assert False, "Method should not time out"
+            finally:
+                signal.alarm(0)
+

utilities_common/auto_techsupport_helper.py

@@ -11,8 +11,9 @@
             "CORE_DUMP_DIR", "CORE_DUMP_PTRN", "TS_DIR", "TS_PTRN",
             "CFG_DB", "AUTO_TS", "CFG_STATE", "CFG_MAX_TS", "COOLOFF",
             "CFG_CORE_USAGE", "CFG_SINCE", "FEATURE", "STATE_DB",
-            "TS_MAP", "CORE_DUMP", "TIMESTAMP", "CONTAINER",
-            "TIME_BUF", "SINCE_DEFAULT", "TS_PTRN_GLOB"
+            "TS_MAP", "CORE_DUMP", "TIMESTAMP", "CONTAINER", "TIME_BUF",
+            "SINCE_DEFAULT", "TS_PTRN_GLOB", "EXT_LOCKFAIL", "EXT_RETRY",
+            "EXT_SUCCESS", "MAX_RETRY_LIMIT"
         ] + [  # Methods
             "verify_recent_file_creation",
             "get_ts_dumps",
@@ -60,6 +61,11 @@
 TIME_BUF = 20
 SINCE_DEFAULT = "2 days ago"
 
+# Techsupport Exit Codes
+EXT_LOCKFAIL = 2
+EXT_RETRY = 4
+EXT_SUCCESS = 0
+MAX_RETRY_LIMIT = 2
 
 # Helper methods
 def subprocess_exec(cmd, env=None):