modularized all source code (#4391)

* modularized all external plugins

* added README.md in plugins

* fixed title

* fixed typo

* relative link to external plugins

* external plugins configuration README

* added plugins link

* remove plugins link

* plugin names are links

* added links to external plugins

* removed unecessary spacing

* list to table

* added language

* fixed typo

* list to table on internal plugins

* added more documentation to internal plugins

* moved python, node, and bash code and configs into the external plugins

* added statsd README

* fix bug with corrupting config.h every 2nd compilation

* moved all config files together with their code

* more documentation

* diskspace info

* fixed broken links in apps.plugin

* added backends docs

* updated plugins readme

* move nc-backend.sh to backends

* created daemon directory

* moved all code outside src/

* fixed readme identation

* renamed plugins.d.plugin to plugins.d

* updated readme

* removed linux- from linux plugins

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* fixed README.md links

* fixed netdata tree links

* updated codacy, codeclimate and lgtm excluded paths

* update CMakeLists.txt

* updated automake options at top directory

* libnetdata slit into directories

* updated READMEs

* updated READMEs

* updated ARL docs

* updated ARL docs

* moved /plugins to /collectors

* moved all external plugins outside plugins.d

* updated codacy, codeclimate, lgtm

* updated README

* updated url

* updated readme

* updated readme

* updated readme

* updated readme

* moved api and web into webserver

* web/api web/gui web/server

* modularized webserver

* removed web/gui/version.txt

89 files changed, 24364 insertions, 0 deletions

diff --git a/collectors/python.d.plugin/python_modules/__init__.py b/collectors/python.d.plugin/python_modules/__init__.py
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/collectors/python.d.plugin/python_modules/__init__.py
diff --git a/collectors/python.d.plugin/python_modules/bases/FrameworkServices/ExecutableService.py b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/ExecutableService.py
new file mode 100644
index 0000000000..72f9ff714f
--- /dev/null
+++ b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/ExecutableService.py
@@ -0,0 +1,89 @@
+# -*- coding: utf-8 -*-
+# Description:
+# Author: Pawel Krupa (paulfantom)
+# Author: Ilya Mashchenko (l2isbad)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+import os
+
+from subprocess import Popen, PIPE
+
+from bases.FrameworkServices.SimpleService import SimpleService
+from bases.collection import find_binary
+
+
+class ExecutableService(SimpleService):
+    def __init__(self, configuration=None, name=None):
+        SimpleService.__init__(self, configuration=configuration, name=name)
+        self.command = None
+
+    def _get_raw_data(self, stderr=False, command=None):
+        """
+        Get raw data from executed command
+        :return: <list>
+        """
+        try:
+            p = Popen(command if command else self.command, stdout=PIPE, stderr=PIPE)
+        except Exception as error:
+            self.error('Executing command {command} resulted in error: {error}'.format(command=command or self.command,
+                                                                                       error=error))
+            return None
+        data = list()
+        std = p.stderr if stderr else p.stdout
+        for line in std:
+            try:
+                data.append(line.decode('utf-8'))
+            except TypeError:
+                continue
+
+        return data
+
+    def check(self):
+        """
+        Parse basic configuration, check if command is whitelisted and is returning values
+        :return: <boolean>
+        """
+        # Preference: 1. "command" from configuration file 2. "command" from plugin (if specified)
+        if 'command' in self.configuration:
+            self.command = self.configuration['command']
+
+        # "command" must be: 1.not None 2. type <str>
+        if not (self.command and isinstance(self.command, str)):
+            self.error('Command is not defined or command type is not <str>')
+            return False
+
+        # Split "command" into: 1. command <str> 2. options <list>
+        command, opts = self.command.split()[0], self.command.split()[1:]
+
+        # Check for "bad" symbols in options. No pipes, redirects etc.
+        opts_list = ['&', '|', ';', '>', '<']
+        bad_opts = set(''.join(opts)) & set(opts_list)
+        if bad_opts:
+            self.error("Bad command argument(s): {opts}".format(opts=bad_opts))
+            return False
+
+        # Find absolute path ('echo' => '/bin/echo')
+        if '/' not in command:
+            command = find_binary(command)
+            if not command:
+                self.error('Can\'t locate "{command}" binary'.format(command=self.command))
+                return False
+        # Check if binary exist and executable
+        else:
+            if not os.access(command, os.X_OK):
+                self.error('"{binary}" is not executable'.format(binary=command))
+                return False
+
+        self.command = [command] + opts if opts else [command]
+
+        try:
+            data = self._get_data()
+        except Exception as error:
+            self.error('_get_data() failed. Command: {command}. Error: {error}'.format(command=self.command,
+                                                                                       error=error))
+            return False
+
+        if isinstance(data, dict) and data:
+            return True
+        self.error('Command "{command}" returned no data'.format(command=self.command))
+        return False
diff --git a/collectors/python.d.plugin/python_modules/bases/FrameworkServices/LogService.py b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/LogService.py
new file mode 100644
index 0000000000..5acfd73f8e
--- /dev/null
+++ b/collectors/python.d.plugin/python_modules/bases/FrameworkServices/LogService.py
@@ -0,0 +1,80 @@
+# -*- coding: utf-8 -*-
+# Description:
+# Author: Pawel Krupa (paulfantom)
+# Author: Ilya Mashchenko (l2isbad)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from glob import glob
+import os
+
+from bases.FrameworkServices.SimpleService import SimpleService
+
+
+class LogService(SimpleService):
+    def __init__(self, configuration=None, name=None):
+        SimpleService.__init__(self, configuration=configuration, name=name)
+        self.log_path = self.configuration.get('path')
+        self.__glob_path = self.log_path
+        self._last_position = 0
+        self.__re_find = dict(current=0, run=0, maximum=60)
+
+    def _get_raw_data(self):
+        """
+        Get log lines since last poll
+        :return: list
+        """
+        lines = list()
+        try:
+            if self.__re_find['current'] == self.__re_find['run']:
+                self._find_recent_log_file()
+            size = os.path.getsize(self.log_path)
+            if size == self._last_position:
+                self.__re_find['current'] += 1
+                return list()  # return empty list if nothing has changed
+            elif size < self._last_position:
+                self._last_position = 0  # read from beginning if file has shrunk
+
+            with open(self.log_path) as fp:
+                fp.seek(self._last_position)
+                for line in fp:
+                    lines.append(line)
+                self._last_position = fp.tell()
+                self.__re_find['current'] = 0
+        except (OSError, IOError) as error:
+            self.__re_find['current'] += 1
+            self.error(str(error))
+
+        return lines or None
+
+    def _find_recent_log_file(self):
+        """
+        :return:
+        """
+        self.__re_find['run'] = self.__re_find['maximum']
+        self.__re_find['current'] = 0
+        self.__glob_path = self.__glob_path or self.log_path  # workaround for modules w/o config files
+        path_list = glob