implemented metrics and agent fsm

.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+env/
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+
+# PyInstaller
+#  Usually these files are written by a python script from a template
+#  before PyInstaller builds the exe, so as to inject date/other infos into it.
+*.manifest
+*.spec
+
+# Installer logs
+pip-log.txt
+pip-delete-this-directory.txt
+
+# Unit test / coverage reports
+htmlcov/
+.tox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*,cover
+.hypothesis/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# dotenv
+.env
+
+# virtualenv
+.venv/
+venv/
+ENV/
+
+# Spyder project settings
+.spyderproject
+
+# Rope project settings
+.ropeproject
+

LICENSE

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+MIT License
+
+Copyright (c) 2016 Instana
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

MANIFEST.in

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+include LICENSE
+include README.md
+include requirements.txt

example/simple.py

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+import sys
+import instana.sensor as s
+import instana.options as o
+import logging as l
+
+def main(argv):
+    sensor = s.Sensor(o.Options(service='python-simple',
+                                log_level=l.DEBUG))
+
+if __name__ == "__main__":
+    main(sys.argv)

instana/__init__.py

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+"""
+Instana sensor and tracer. It consists of two modules that can be used as entry points:
+
+- sensor: activates the meter to collect and transmit all kind of built-in metrics
+- tracer: OpenTracing tracer implementation. It implicitly activates the meter
+"""
+
+__author__ = 'Instana Inc.'
+__copyright__ = 'Copyright 2016 Instana Inc.'
+__credits__ = ['Pavlo Baron']
+__license__ = 'MIT'
+__version__ = '0.0.1'
+__maintainer__ = 'Pavlo Baron'
+__email__ = '[email protected]'
+
+__all__ = ['sensor', 'tracer']

instana/agent.py

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+import json
+import thread
+import urllib2
+import instana.log as l
+import instana.fsm as f
+
+class From(object):
+    pid = ""
+    hostId = ""
+    def __init__(self, **kwds):
+        self.__dict__.update(kwds)
+
+class Head(urllib2.Request):
+    def get_method(self):
+        return "HEAD"
+
+class Put(urllib2.Request):
+    def get_method(self):
+        return "PUT"
+
+class Agent(object):
+    AGENT_DISCOVERY_URL = "/com.instana.plugin.python.discovery"
+    AGENT_TRACES_URL    = "/com.instana.plugin.python/traces."
+    AGENT_DATA_URL      = "/com.instana.plugin.python."
+    AGENT_DEFAULT_HOST  = "localhost"
+    AGENT_DEFAULT_PORT  = 42699
+    AGENT_HEADER        = "Instana Agent"
+
+    sensor = None
+    host = AGENT_DEFAULT_HOST
+    fsm = None
+    from_ = None
+
+    def __init__(self, sensor):
+        l.debug("initializing agent")
+
+        self.sensor = sensor
+        self.fsm = f.Fsm(self)
+        self.reset()
+
+    def to_json(self, o):
+        return json.dumps(o, default=lambda o: o.__dict__, sort_keys=False, indent=4)
+
+    def can_send(self):
+        return self.fsm.fsm.current == "ready"
+
+    def head(self, url):
+        return self.request(url, "HEAD", None)
+
+    def request(self, url, method, o):
+        return self.full_request_response(url, method, o, False, "")
+
+    def request_response(self, url, method, o):
+        return self.full_request_response(url, method, o, True, "")
+
+    def request_header(self, url, method, header):
+        return self.full_request_response(url, method, None, False, header)
+
+    def full_request_response(self, url, method, o, body, header):
+        b = None
+        h = None
+        try:
+            if method == "HEAD":
+                request = Head(url)
+            elif method == "GET":
+                request = urllib2.Request(url)
+            elif method == "PUT":
+                request = Put(url, self.to_json(o))
+                request.add_header("Content-Type", "application/json")
+            else:
+                request = urllib2.Request(url, self.to_json(o))
+                request.add_header("Content-Type", "application/json")
+
+            response = urllib2.urlopen(request, timeout=2)
+
+            if not response:
+                self.reset()
+            else:
+                if response.getcode() < 200 or response.getcode() >= 300:
+                    l.error("Request returned erroneous code", response.getcode())
+                    if self.can_send():
+                        self.reset()
+                else:
+                    if body:
+                        b = response.read()
+
+                    if header:
+                        h = response.info().getheader(header)
+
+                    if method == "HEAD":
+                        b = True
+        except Exception as e:
+            l.error(str(e))
+
+        return (b, h)
+
+    def make_url(self, prefix):
+        return self.make_host_url(self.host, prefix)
+
+    def make_host_url(self, host, prefix):
+        port = self.sensor.options.agent_port
+    	if port == 0:
+    		port = self.AGENT_DEFAULT_PORT
+
+    	return self.make_full_url(host, port, prefix)
+
+    def make_full_url(self, host, port, prefix):
+        s = "http://%s:%s%s" % (host, str(port), prefix)
+        if self.from_.pid != 0:
+            s = "%s%s" % (s, self.from_.pid)
+
+        return s
+
+    def reset(self):
+        self.from_ = From()
+        self.fsm.reset()
+
+    def set_host(self, host):
+        self.host = host
+
+    def set_from(self, from_):
+        self.from_ = From(**json.loads(from_))

instana/fsm.py

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+import subprocess
+import os
+import sys
+import threading as t
+import fysom as f
+import instana.log as l
+
+class Discovery(object):
+    pid = 0
+    name = None
+    args = None
+    def __init__(self, **kwds):
+        self.__dict__.update(kwds)
+
+class Fsm(object):
+    E_START     = "start"
+    E_LOOKUP   = "lookup"
+    E_ANNOUNCE = "announce"
+    E_TEST     = "test"
+
+    RETRY_PERIOD = 5#30
+
+    agent = None
+    fsm = None
+
+    def __init__(self, agent):
+        l.debug("initializing fsm")
+
+        self.agent = agent
+        self.fsm = f.Fysom({
+    		"initial": "none",
+    		"events": [
+    			{"name": self.E_START, "src": ["none", "unannounced", "announced", "ready"], "dst": "init"},
+    			{"name": self.E_LOOKUP, "src": "init", "dst": "unannounced"},
+    			{"name": self.E_ANNOUNCE, "src": "unannounced", "dst": "announced"},
+    			{"name": self.E_TEST, "src": "announced", "dst": "ready"}],
+    		"callbacks": {
+    			"onstart": self.lookup_agent_host,
+    			"onenterunannounced": self.announce_sensor,
+    			"onenterannounced": self.test_agent}})
+
+    def reset(self):
+        self.fsm.start()
+
+    def lookup_agent_host(self, e):
+        if self.agent.sensor.options.agent_host != "":
+            host = self.agent.sensor.options.agent_host
+        else:
+            host = self.agent.AGENT_DEFAULT_HOST
+
+        h = self.check_host(host)
+        if h == self.agent.AGENT_HEADER:
+            self.agent.set_host(host)
+            self.fsm.lookup()
+        else:
+            self.check_host(self.get_default_gateway())
+            if h == self.agent.AGENT_HEADER:
+                self.agent.set_host(host)
+                self.fsm.lookup()
+
+    def get_default_gateway(self):
+        l.debug("checking default gateway")
+        proc = subprocess.Popen("/sbin/ip route | awk '/default/ { print $3 }'", stdout=subprocess.PIPE)
+
+        return proc.stdout.read()
+
+    def check_host(self, host):
+        l.debug("checking host", host)
+
+        (b, h) = self.agent.request_header(self.agent.make_host_url(host, "/"), "GET", "Server")
+
+        return h
+
+    def announce_sensor(self, e):
+        l.debug("announcing sensor to the agent")
+
+        d = Discovery(pid=os.getpid(),
+                      name=sys.executable,
+                      args=sys.argv[0:])
+
+        (b, h) = self.agent.request_response(self.agent.make_url(self.agent.AGENT_DISCOVERY_URL), "PUT", d)
+        if not b:
+            l.error("Cannot announce sensor. Scheduling retry.")
+            self.schedule_retry(self.announce_sensor, e)
+        else:
+            self.agent.set_from(b)
+            self.fsm.announce()
+
+    def schedule_retry(self, f, e):
+        t.Timer(self.RETRY_PERIOD, f, [e]).start()
+
+    def test_agent(self, e):
+        l.debug("testing communication with the agent")
+
+        (b, h) = self.agent.head(self.agent.make_url(self.agent.AGENT_DATA_URL))
+
+        if not b:
+            self.schedule_retry(self.test_agent, e)
+        else:
+            self.fsm.test()

instana/log.py

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+import logging as l
+
+logger = l.getLogger('instana')
+
+def init(level):
+    ch = l.StreamHandler()
+    f = l.Formatter('%(asctime)s: %(levelname)s: %(name)s: %(message)s')
+    ch.setFormatter(f)
+    logger.addHandler(ch)
+    logger.setLevel(level)
+
+def debug(s, *args):
+    logger.debug("%s %s" % (s, ' '.join(args)))
+
+def info(s, *args):
+    logger.info("%s %s" % (s, ' '.join(args)))
+
+def warn(s, *args):
+    logger.warn("%s %s" % (s, ' '.join(args)))
+
+def error(s, *args):
+    logger.error("%s %s" % (s, ' '.join(args)))