Initial commit

.editorconfig

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+root = true
+
+[Makefile]
+indent_style = tab
+
+[*.py]
+charset = utf-8
+indent_style = space
+indent_size = 4

.gitignore

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+# Byte-compiled / optimized / DLL files
+__pycache__/
+*.py[cod]
+*$py.class
+
+# C extensions
+*.so
+
+# Distribution / packaging
+.Python
+build/
+develop-eggs/
+dist/
+downloads/
+eggs/
+.eggs/
+lib/
+lib64/
+parts/
+sdist/
+var/
+wheels/
+pip-wheel-metadata/
+share/python-wheels/
+*.egg-info/
+.installed.cfg
+*.egg
+MANIFEST
+
+# 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/
+.nox/
+.coverage
+.coverage.*
+.cache
+nosetests.xml
+coverage.xml
+*.cover
+.hypothesis/
+.pytest_cache/
+
+# Translations
+*.mo
+*.pot
+
+# Django stuff:
+*.log
+local_settings.py
+db.sqlite3
+
+# Flask stuff:
+instance/
+.webassets-cache
+
+# Scrapy stuff:
+.scrapy
+
+# Sphinx documentation
+docs/_build/
+
+# PyBuilder
+target/
+
+# Jupyter Notebook
+.ipynb_checkpoints
+
+# IPython
+profile_default/
+ipython_config.py
+
+# pyenv
+.python-version
+
+# celery beat schedule file
+celerybeat-schedule
+
+# SageMath parsed files
+*.sage.py
+
+# Environments
+.env
+.venv
+env/
+venv/
+ENV/
+env.bak/
+venv.bak/
+
+# Spyder project settings
+.spyderproject
+.spyproject
+
+# Rope project settings
+.ropeproject
+
+# mkdocs documentation
+/site
+
+# mypy
+.mypy_cache/
+.dmypy.json
+dmypy.json
+
+# Pyre type checker
+.pyre/
+
+# JetBrains IDE
+.idea
+
+# MacOS
+.DS_Store

LICENSE

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+MIT License
+
+Copyright (c) 2019 Andrey Maslov
+
+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.

README.md

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+python-logging-loki
+===================
+
+[![PyPI version](https://img.shields.io/pypi/v/python-logging-loki.svg)](https://pypi.org/project/python-logging-loki/)
+[![Python version](https://img.shields.io/badge/python-3.5%20%7C%203.6%20%7C%203.7-blue.svg)](https://www.python.org/)
+[![License](https://img.shields.io/pypi/l/python-logging-loki.svg)](https://opensource.org/licenses/MIT)
+
+Python logging handler for Loki.  
+https://grafana.com/loki
+
+Installation
+============
+```bash
+pip install python-logging-loki
+```
+
+Usage
+=====
+
+```python
+import logging
+import logging_loki
+
+
+handler = logging_loki.LokiHandler(
+    url="https://my-loki-instnace/api/prom/push", 
+    tags={"application": "my-app"},
+    auth=("username", "password"),    
+)
+
+logger = logging.getLogger("my-logger")
+logger.addHandler(handler)
+logger.error(
+    "Something happened", 
+    extra={"tags": {"service": "my-service"}},
+)
+```
+
+Example above will send `Something happened` message along with these labels:
+- Default labels from handler
+- Message level as `serverity`
+- Logger's name as `logger` 
+- Labels from `tags` item of `extra` dict
+
+The given example is blocking (i.e. each call will wait for the message to be sent).  
+But you can use the built-in `QueueHandler` and` QueueListener` to send messages in a separate thread.  
+
+```python
+import logging.handlers
+import logging_loki
+from queue import Queue
+
+
+queue = Queue(-1)
+handler = logging.handlers.QueueHandler(queue)
+handler_loki = logging_loki.LokiHandler(
+    url="https://my-loki-instnace/api/prom/push", 
+    tags={"application": "my-app"},
+    auth=("username", "password"),    
+)
+logging.handlers.QueueListener(queue, handler_loki)
+
+logger = logging.getLogger("my-logger")
+logger.addHandler(handler)
+logger.error(...)
+```
+
+Or you can use `LokiQueueHandler` shortcut, which will automatically create listener and handler.
+
+```python
+import logging.handlers
+import logging_loki
+from queue import Queue
+
+
+handler = logging_loki.LokiQueueHandler(
+    Queue(-1),
+    url="https://my-loki-instnace/api/prom/push", 
+    tags={"application": "my-app"},
+    auth=("username", "password"),
+)
+
+logger = logging.getLogger("my-logger")
+logger.addHandler(handler)
+logger.error(...)
+```

logging_loki/__init__.py

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+from .handlers import LokiHandler, LokiQueueHandler
+
+__all__ = ["LokiHandler", "LokiQueueHandler"]
+__version__ = "0.1.0"
+name = "logging_loki"

logging_loki/handlers.py

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+import logging
+from logging.handlers import QueueHandler, QueueListener
+from queue import Queue
+from typing import Optional, Tuple, Dict, Any
+
+import requests
+import rfc3339
+
+BasicAuth = Optional[Tuple[str, str]]
+
+
+class LokiQueueHandler(QueueHandler):
+    """
+    This handler automatically creates listener and `LokiHandler` to handle logs queue.
+    """
+
+    def __init__(self, queue: Queue, url: str, tags: Optional[dict] = None, auth: BasicAuth = None):
+        super().__init__(queue)
+        self.handler = LokiHandler(url, tags, auth)
+        self.listener = QueueListener(self.queue, self.handler)
+        self.listener.start()
+
+
+class LokiHandler(logging.Handler):
+    """
+    This handler sends log records to Loki via HTTP API.
+    https://github.com/grafana/loki/blob/master/docs/api.md
+    """
+
+    level_tag: str = "severity"
+    logger_tag: str = "logger"
+
+    def __init__(self, url: str, tags: Optional[dict] = None, auth: BasicAuth = None):
+        super().__init__()
+
+        # Tags that will be added to all records handled by this handler.
+        self.tags = tags or {}
+
+        # Loki HTTP API endpoint (e.g `http://127.0.0.1/api/prom/push`)
+        self.url = url
+
+        # Optional tuple with username and password for basic authentication
+        self.auth = auth
+
+        self._session: requests.Session = None
+
+    @property
+    def session(self) -> requests.Session:
+        if self._session is None:
+            self._session = requests.Session()
+            self._session.auth = self.auth or None
+        return self._session
+
+    def handleError(self, record):
+        super().handleError(record)
+        if self._session is not None:
+            self._session.close()
+            self._session = None
+
+    def emit(self, record: logging.LogRecord):
+        """
+        Send log record to Loki.
+        """
+        # noinspection PyBroadException
+        try:
+            labels = self.build_labels(record)
+            ts = rfc3339.format(record.created)
+            line = self.format(record)
+            payload = {"streams": [{"labels": labels, "entries": [{"ts": ts, "line": line}]}]}
+            resp = self.session.post(self.url, json=payload)
+            if resp.status_code != 204:
+                raise ValueError("Unexpected Loki API response status code: %s" % resp.status_code)
+        except Exception:
+            self.handleError(record)
+
+    def build_labels(self, record: logging.LogRecord) -> str:
+        """
+        Return Loki labels string.
+        """
+        tags = self.build_tags(record)
+        labels = ",".join(['%s="%s"' % (k, str(v).replace('"', '\\"')) for k, v in tags.items()])
+        return "{%s}" % labels
+
+    def build_tags(self, record: logging.LogRecord) -> Dict[str, Any]:
+        """
+        Return tags that must be send to Loki with a log record.
+        """
+        tags = self.tags.copy()
+        tags[self.level_tag] = record.levelname.lower()
+        tags[self.logger_tag] = record.name
+
+        extra_tags = getattr(record, "tags", {})
+        if isinstance(extra_tags, dict):
+            tags.update(extra_tags)
+
+        return tags

pyproject.toml

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+[tool.black]
+line-length = 120
+py36 = true
+exclude = '''
+/(
+  \.git
+)/
+'''

setup.py

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+import setuptools
+
+with open("README.md", "r") as fh:
+    long_description = fh.read()
+
+setuptools.setup(
+    name="python-logging-loki",
+    version="0.1.0",
+    description="Python logging handler for Grafana Loki.",
+    long_description=long_description,
+    long_description_content_type="text/markdown",
+    license="MIT",
+    author="Andrey Maslov",
+    author_email="greyzmeem@gmail.com",
+    url="https://github.com/greyzmeem/python-logging-loki",
+    packages=setuptools.find_packages(),
+    python_requires=">=3.5",
+    install_requires=["rfc3339", "requests"],
+    classifiers=[
+        "Development Status :: 4 - Beta",
+        "Intended Audience :: Developers",
+        "License :: OSI Approved :: MIT License",
+        "Operating System :: OS Independent",
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
+        "Topic :: Software Development :: Libraries :: Python Modules",
+        "Topic :: System :: Logging",
+        "Topic :: Internet :: WWW/HTTP",
+    ],
+)