Add support for journalctl output

The lines in the "Mem-Info:" block start with spaces instead of date /
time / hostname. As a result, removing the needless columns no longer
works correctly.

Suggested-by: Mikko Rantalainen <mikko.rantalainen@gmail.com>

OOMAnalyser.html

@@ -897,6 +897,7 @@ window.onerror = function (msg, url, lineNo, columnNo, error) {
         <li>Add support for manually triggered OOM (suggested by Mikko Rantalainen)</li>
         <li>Add support for systems w/o swap (suggested by Mikko Rantalainen)</li>
         <li>Add support for newer kernels (suggested by Mikko Rantalainen)</li>
+        <li>Add support for journalctl output (suggested by Mikko Rantalainen)</li>
         <li>...</li>
     </ol>
 

OOMAnalyser.py

@@ -525,6 +525,7 @@ class OOMEntity:
         oom_lines = self._remove_non_oom_lines(oom_lines)
         oom_lines = self._remove_kernel_colon(oom_lines)
         cols_to_strip = self._number_of_columns_to_strip(oom_lines[self._get_CPU_index(oom_lines)])
+        oom_lines = self._journalctl_add_leading_columns_to_meminfo(oom_lines, cols_to_strip)
         oom_lines = self._strip_needless_columns(oom_lines, cols_to_strip)
         oom_lines = self._rsyslog_unescape_lf(oom_lines)
 
@@ -536,6 +537,34 @@ class OOMEntity:
         else:
             self.state = OOMEntityState.started
 
+    def _journalctl_add_leading_columns_to_meminfo(self, oom_lines, cols_to_add):
+        """
+        Add leading columns to handle line breaks in journalctl output correctly.
+
+        The output of the "Mem-Info:" block contains line breaks. journalctl breaks these lines accordingly, but
+        inserts at the beginning spaces instead of date and time. As a result, removing the needless columns no longer
+        works correctly.
+
+        This function adds columns back in the affected rows so that the removal works cleanly over all rows.
+
+        @see: _rsyslog_unescape_lf()
+        """
+        pattern = r'^\s+ (active_file|unevictable|slab_reclaimable|mapped|free):.+$'
+        rec = re.compile(pattern)
+
+        add_cols = ""
+        for i in range(cols_to_add):
+            add_cols += "Col{} ".format(i)
+
+        expanded_lines = []
+        for line in oom_lines:
+            match = rec.search(line)
+            if match:
+                line = "{} {}".format(add_cols, line.strip())
+            expanded_lines.append(line)
+
+        return expanded_lines
+
     def _get_CPU_index(self, lines):
         """
         Return the index of the first line with "CPU: "
@@ -605,12 +634,17 @@ class OOMEntity:
 
     def _rsyslog_unescape_lf(self, oom_lines):
         """
-        Rsyslog replaces line breaks with their octal representation #012.
+        Split lines at '#012' (octal representation of LF).
+
+        The output of the "Mem-Info:" block contains line breaks. Rsyslog replaces these line breaks with their octal
+        representation #012. This breaks the removal of needless columns as well as the detection of the OOM values.
+
+        Splitting the lines (again) solves this issue.
 
         This feature can be controlled inside the rsyslog configuration with the directives
         $EscapeControlCharactersOnReceive, $Escape8BitCharactersOnReceive and $ControlCharactersEscapePrefix.
 
-        The replacement is only in second line (active_anon:....) of the Mem-Info block.
+        @see: _journalctl_add_leading_columns_to_meminfo()
         """
         lines = []
 

test.py

@@ -304,6 +304,37 @@ Killed process 6576 (java) total-vm:33914892kB, anon-rss:20629004kB, file-rss:0k
         self.assertEqual(self.get_error_text(), "ERROR: Failed to extract kernel version from OOM text")
         self.click_reset()
 
+    def test_035_leading_journalctl_input(self):
+        """Test loading input from journalctl """
+        # prepare example
+        example_lines = OOMAnalyser.OOMDisplay.example_rhel7.split('\n')
+        res = []
+
+        # unescape #012 - see OOMAnalyser.OOMEntity._rsyslog_unescape_lf()
+        for line in example_lines:
+            if '#012' in line:
+                res.extend(line.split('#012'))
+            else:
+                res.append(line)
+        example_lines = res
+        res = []
+
+        # add date/time prefix except for "Mem-Info:" block
+        pattern = r'^ (active_file|unevictable|slab_reclaimable|mapped|free):.+$'
+        rec = re.compile(pattern)
+        for line in example_lines:
+            match = rec.search(line)
+            if match:
+                line = "                                             {}".format(line)
+            else:
+                line = "Apr 01 14:13:32 mysrv <kern.warning> kernel: {}".format(line)
+            res.append(line)
+        example = "\n".join(res)
+
+        self.analyse_oom(example)
+        self.check_results_rhel7()
+        self.click_reset()
+
     def test_040_trigger_proc_space(self):
         """Test trigger process name contains a space"""
         example = OOMAnalyser.OOMDisplay.example_rhel7