commonlog (Python)

A unified logging and alerting library for Python, supporting Slack and Lark integrations via WebClient and Webhook. Features configurable providers, alert levels, and file attachment support.

Installation

Install via pip:

pip install commonlog

Or copy the python/ directory to your project.

Usage

from python import commonlog, Config, SendMethod, AlertLevel, Attachment, LarkToken

# Configure logger
config = Config(
    provider="lark", # or "slack"
    send_method=SendMethod.WEBCLIENT,
    token="app_id++app_secret", # for Lark, use "app_id++app_secret" format
    slack_token="xoxb-your-slack-token", # dedicated Slack token
    lark_token=LarkToken(app_id="your-app-id", app_secret="your-app-secret"), # dedicated Lark token
    channel="your_lark_channel_id",
    redis_host="localhost", # required for Lark
    redis_port="6379",      # required for Lark
)
logger = commonlog(config)

# Send error with attachment
try:
    logger.send(AlertLevel.ERROR, "System error occurred", Attachment(url="https://example.com/log.txt"))
except Exception as e:
    print(f"Failed to send alert: {e}")

 # Send info (logs only)
logger.send(AlertLevel.INFO, "Info message")

# Send to a specific channel
try:
    logger.send_to_channel(AlertLevel.ERROR, "Send to another channel", channel="another-channel-id")
except Exception as e:
    print(f"Failed to send alert: {e}")

# Send to a different provider dynamically
try:
    logger.custom_send("slack", AlertLevel.ERROR, "Message via Slack", channel="slack-channel")
except Exception as e:
    print(f"Failed to send alert: {e}")

Send Methods

commonlog supports two send methods: WebClient (API-based) and Webhook (simple HTTP POST).

WebClient Usage

WebClient uses the full API with authentication tokens:

config = Config(
    provider="lark",
    send_method=SendMethod.WEBCLIENT,
    token="app_id++app_secret",  # for Lark
    slack_token="xoxb-your-slack-token",  # for Slack
    lark_token=LarkToken(app_id="your-app-id", app_secret="your-app-secret"),
    channel="your_channel",
    redis_host="localhost",  # required for Lark
    redis_port="6379",
)

Webhook Usage

Webhook is simpler and requires only a webhook URL:

config = Config(
    provider="slack",
    send_method=SendMethod.WEBHOOK,
    token="https://hooks.slack.com/services/YOUR/WEBHOOK/URL",
    channel="optional-channel-override",  # optional
)

Lark Token Caching

When using Lark, the tenant_access_token is cached in Redis. The expiry is set dynamically from the API response minus 10 minutes. You must set redis_host and redis_port in your config.

Channel Mapping

You can configure different channels for different alert levels using a channel resolver:

from commonlog import commonlog, Config, SendMethod, AlertLevel, DefaultChannelResolver

# Create a channel resolver
resolver = DefaultChannelResolver(
    channel_map={
        AlertLevel.INFO: "#general",
        AlertLevel.WARN: "#warnings",
        AlertLevel.ERROR: "#alerts",
    },
    default_channel="#general"
)

# Create config with channel resolver
config = Config(
    provider="slack",
    send_method=SendMethod.WEBCLIENT,
    token="xoxb-your-slack-bot-token",
    channel_resolver=resolver,
    service_name="user-service",
    environment="production"
)

logger = commonlog(config)

# These will go to different channels based on level
logger.send(AlertLevel.INFO, "Info message")    # goes to #general
logger.send(AlertLevel.WARN, "Warning message") # goes to #warnings
logger.send(AlertLevel.ERROR, "Error message")  # goes to #alerts

Custom Channel Resolver

You can implement custom channel resolution logic:

class CustomResolver(ChannelResolver):
    def resolve_channel(self, level):
        if level == AlertLevel.ERROR:
            return "#critical-alerts"
        elif level == AlertLevel.WARN:
            return "#monitoring"
        else:
            return "#general"

Configuration Options

Common Settings

• provider: "slack" or "lark"
• send_method: "webclient" (token-based authentication)
• channel: Target channel or chat ID (used if no resolver)
• channel_resolver: Optional resolver for dynamic channel mapping
• service_name: Name of the service sending alerts
• environment: Environment (dev, staging, production)
• debug: True to enable detailed debug logging of all internal processes

Provider-Specific

• token: API token for WebClient authentication (required)

Alert Levels

• INFO: Logs locally only
• WARN: Logs + sends alert
• ERROR: Always sends alert

File Attachments

Provide a public URL. The library appends it to the message for simplicity.

attachment = Attachment(url="https://example.com/log.txt")
logger.send(AlertLevel.ERROR, "Error with log", attachment)

Trace Log Section

When include_trace is set to True, you can pass trace information as the fourth parameter to send():

trace = """Traceback (most recent call last):
  File "app.py", line 10, in main
    raise ValueError("Something went wrong")
ValueError: Something went wrong"""

logger.send(AlertLevel.ERROR, "System error occurred", None, trace)

This will format the trace as a code block in the alert message.

Testing

cd python
PYTHONPATH=.. python -m unittest test_commonlog.py

API Reference

Classes

• Config: Configuration class
• Attachment: File attachment class
• Provider: Abstract base class for alert providers
• commonlog: Main logger class

Constants

• SendMethod.WEBCLIENT: Send method (token-based authentication)
• AlertLevel.INFO, AlertLevel.WARN, AlertLevel.ERROR: Alert levels

Methods

• commonlog(config): Create a new logger
• commonlog.send(level, message, attachment=None, trace=""): Send alert with optional trace