[coredump] Refactor info and dump collection

sos/report/plugins/coredump.py

@@ -8,36 +8,111 @@
 #
 # See the LICENSE file in the source distribution for further information.
 
+import os
+import re
 from sos.report.plugins import Plugin, IndependentPlugin, PluginOpt
 
 
 class Coredump(Plugin, IndependentPlugin):
+    """
+    This plugin collects from the systemd-coredump service, which is leveraged
+    via the coredumpctl command.
 
-    short_desc = 'Retrieve coredump information'
+    Beyond basic configuration of the service, the plugin will also attempt to
+    collect information on available coredumps. For any coredumps reported by
+    coredumpctl for which the core is present, this plugin will collect that
+    coredump file. The number of dump files collects is controlled by the
+    `dumps` option, defaulting to 3. Note that core collection is performed
+    based on the most recent cores generated. The summary information provided
+    by `coredumpctl info` is also collected.
+
+    The coredump files will be at their canonical location in the sos archive,
+    usually under var/lib/systemd/coredump. Symlinks are dropped in the plugin
+    directory to assist in identifying which coredump aligns to which entry in
+    the provided `coredumpctl list` output collection.
+
+    Users may leverage the `executable` option to control which coredumps the
+    plugin will collect. This option takes a case-insensitive python regex
+    string. If provided, only coredump entries for which the EXE field in
+    `coredumpctl list` output matches will be collected.
+
+    The dump files collected are compressed, and users should be aware that
+    when inflated these files can be orders of magnitude larger than their
+    collected sizes.
+    """
+
+    short_desc = 'systemd-coredump related information and dump files'
 
     plugin_name = "coredump"
     profiles = ('system', 'debug')
     packages = ('systemd-udev', 'systemd-coredump')
 
     option_list = [
-        PluginOpt("detailed", default=False,
-                  desc="collect detailed information for every report")
+        PluginOpt("dumps", default=3, desc="number of dump files to collect"),
+        PluginOpt("executable", default='',
+                  desc=("only collect info and dump output for executables "
+                        "matching this regex"))
     ]
 
     def setup(self):
         self.add_copy_spec([
             "/etc/systemd/coredump.conf",
             "/etc/systemd/coredump.conf.d/",
             "/run/systemd/coredump.conf.d/",
-            "/usr/lib/systemd/coredump.conf.d/"
+            "/usr/lib/systemd/coredump.conf.d/",
+            "/usr/lib/systemd/systemd-coredump"
         ])
 
-        self.add_cmd_output("coredumpctl dump")
+        coredump_list = self.collect_cmd_output("coredumpctl list --reverse")
+        if coredump_list['status'] != 0:
+            return
 
-        coredump_list = self.collect_cmd_output("coredumpctl list")
-        if self.get_option("detailed") and coredump_list['status'] == 0:
-            for line in coredump_list["output"].splitlines()[1:]:
-                self.add_cmd_output("coredumpctl info "
-                                    f"{line.split()[4]}")
+        cores_collected = 0
+        for line in coredump_list["output"].splitlines()[1:]:
+            cdump = line.split()
+            pid = cdump[4]
+            exe = cdump[-2]
+            if regex := self.get_option("executable"):
+                if not re.search(regex, exe, re.I):
+                    continue
+            cinfo = self.collect_cmd_output(f"coredumpctl info {pid}")
+            if cinfo['status'] != 0:
+                continue
+            res = cinfo['output']
+            if cores_collected < self.get_option("dumps"):
+                core = re.search(r"(^\s*Storage:(.*)(\(present\)))", res, re.M)
+                try:
+                    core_path = core.groups()[1].strip()
+                    # a_c_s does not return any information for a skipped file,
+                    # so stat the size here and if the core is larger than our
+                    # limit, move on to the next
+                    # TODO: do not hardcode this. Extend log-size to per-plugin
+                    # TODO: option and link this to that value
+                    if os.stat(core_path).st_size > 209715200:
+                        self._log_info(
+                            f"Skipping core dump file {core_path} due to size"
+                        )
+                        continue
+                    self.add_copy_spec(core_path, tailit=False, sizelimit=200)
+                    plugpath = self.path_join(
+                        self.commons['cmddir'],
+                        self.name(),
+                        f"coredump_{pid}_{self._mangle_command(exe)}"
+                    )
+                    # use os.path instead of the plugin wrapper here so that
+                    # we always get the real path of the archive on disk
+                    arcpath = os.path.join(self.archive.get_archive_path(),
+                                           core_path)
+                    linkpath = os.path.relpath(arcpath, plugpath)
+                    linkpath = linkpath.replace('../', '', 1)
+                    self.archive.add_link(linkpath, plugpath)
+                    cores_collected += 1
+                except AttributeError:
+                    # no match on the re.search()
+                    pass
+                except Exception as err:
+                    self._log_info(
+                        f"Could not collect coredump for {pid} : {err}"
+                    )
 
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