[PYTHON] Obtained contents of sosreport

Background examined

• Because it was easy to get started as a study material for Python
• Because there was a person who wanted to know
• More detailed here

https://github.com/sosreport/sos/wiki/

What is sosreport

• A tool for archiving configuration files and command results for systems running Linux
• If you contact OS support etc., you may be asked to obtain it for investigation.

implementation of sosreport

• Language is Python
• Implementations that get configuration files and command results are modularized as plugins
• You can add the distributed plugins or implement and add them yourself.

Plugin storage location

• For sos-3.3-5

/usr/lib/python2.7/site-packages/sos/plugins

Plugin implementation

• Implemented mainly using modules prepared for plugins
• You can guess what you are doing from the method name

Example: yum plugin source

yum.py

from sos.plugins import Plugin, RedHatPlugin


class Yum(Plugin, RedHatPlugin):
    """yum information
    """

    plugin_name = 'yum'
    profiles = ('system', 'packagemanager', 'sysmgmt')

    files = ('/etc/yum.conf',)
    packages = ('yum',)

    option_list = [
        ("yumlist", "list repositories and packages", "slow", False),
        ("yumdebug", "gather yum debugging data", "slow", False)
    ]

    def setup(self):
        # Pull all yum related information
        self.add_copy_spec([
            "/etc/yum",
            "/etc/yum.repos.d",
            "/etc/yum.conf",
            "/var/log/yum.log"
        ])

        # Get a list of channels the machine is subscribed to.
        self.add_cmd_output("yum -C repolist")

        # candlepin info
        self.add_forbidden_path("/etc/pki/entitlement/key.pem")
        self.add_forbidden_path("/etc/pki/entitlement/*-key.pem")
        self.add_copy_spec([
            "/etc/pki/product/*.pem",
            "/etc/pki/consumer/cert.pem",
            "/etc/pki/entitlement/*.pem"
        ])
        self.add_cmd_output("yum history")

        if self.get_option("yumlist"):
            # List various information about available packages
            self.add_cmd_output("yum list")

        if self.get_option("yumdebug") and self.is_installed('yum-utils'):
            # RHEL6+ alternative for this whole function:
            # self.add_cmd_output("yum-debug-dump '%s'"
            # % os.path.join(self.commons['dstroot'],"yum-debug-dump"))
            r = self.call_ext_prog("yum-debug-dump")
            try:
                self.add_cmd_output("zcat %s" % (r['output'].split()[-1],))
            except IndexError:
                pass

• plugin_name Plugin name

• profiles -p (--profile) If you run sosreport with NAME and the value specified for NAME is specified in profiles, the plugin will be executed. You can check which plugin has what profiles with sosreport --list-profiles.

• files, packages If the files specified in files exist or the packages specified in packages are installed, the plugin is enabled by default. The plugin can be enabled / disabled as an option.

• option_list Options that can be specified for plugins From left: option name, option description (check with sosreport -l), fast or slow (no path is currently used as long as you grep the source, it is suggested to remove this item itself), default Valid / invalid.

• setup method Mandatory sosreport loops the setup method of each plugin (around line 1247 of sosreport.py).

sosreport.py

1240     def setup(self):
1241         msg = "[%s:%s] executing 'sosreport %s'"
1242         self.soslog.info(msg % (__name__, "setup", " ".join(self._args)))
1243         self.ui_log.info(_(" Setting up plugins ..."))
1244         for plugname, plug in self.loaded_plugins:
1245             try:
1246                 plug.archive = self.archive
1247                 plug.setup()
1248             except KeyboardInterrupt:
1249                 raise
1250             except (OSError, IOError) as e:
1251                 if e.errno in fatal_fs_errors:
1252                     self.ui_log.error("")
1253                     self.ui_log.error(" %s while setting up plugins"
1254                                       % e.strerror)
1255                     self.ui_log.error("")
1256                     self._exit(1)
1257                 if self.raise_plugins:
1258                     raise
1259                 self._log_plugin_exception(plugname, "setup")
1260             except:
1261                 if self.raise_plugins:
1262                     raise
1263                 self._log_plugin_exception(plugname, "setup")

• add_copy_spec method Copy and get the file.

• add_cmd_output method Get the command execution result.

• add_forbidden_path method Excludes the specified file from the acquisition target.

• get_option method Returns True if the plugin option set in option_list is specified.

• is_installed method Returns True if the specified package is installed.

• call_ext_prog method Returns the command execution result in a process separate from sosreport.

Summarizing the above, the implementation of the yum plugin is as follows.

• • 1 Excluding the following files

/etc/pki/entitlement/key.pem
/etc/pki/entitlement/\*-key.pem

• • 2 Obtained only when the yumdebug option is enabled and the yum-utils package is installed.
• • 3 Obtained only when the yumlist option is enabled