Logging¶

By default, logs are only sent to STDOUT. Optionally logs may be sent to one or more log files or syslog servers.

Logs to each defined target can be filtered - you may want to log certain health check events to a log file and other events to a remote syslog server. You may also define different log levels per log target.

Configuration Keys¶

Logging is configured as an array of LogMethods objects. The following top level configuration keys are available for each object and apply to both file and syslog targets:

Key	Type	Default
`method`	String	`info`
`level`	String	`info`
`formatter`	Optional String	undef
`events`	String	`["announce", "error", "info", "withdraw"]`
`subsystems`	List[String]	`["announcer", "configuration", "executor", "healthcheck", "logging", "master", "notification", "utility", "worker"]`
`checks`	Optional List[String]	undef

Method¶

These log methods are supported:

file: Log to a file.
syslog: Log to a remote syslog server with UDP or TCP.

Warning

You MUST add the method specific configuration noted below otherwise the configuration will be invalid.

Method Specific Configuration¶

The file and syslog methods require specific configuration. Check the relevant page depending on the log method:

Level¶

The level of messages to send to the logging target. Available options are:

error
warning
info
success
debug
trace

Formatter¶

A custom log format string can be provided if you need to change the formatting. As an example, the default log format for STDERR logs is:

<green>{time:YYYY-MM-DD HH:mm:ss.SSS}</green> | <level>{level: <8}</level> | <light-blue>PID {process: <8}</light-blue> | <magenta>{file.path}:{line} {function}()</magenta> | <cyan>{extra[check_name]}</cyan> | <green>{extra[subsystem]}/{extra[event]}</green> | <level>{message}</level>

Events¶

The list of events that may be logged for this target. The following events are supported:

announce: Route announcements
withdraw: Route withdrawals
error: Error logs
info: General information
debug: Verbose debugging information
datadump: Dumps of various data for debugging

Subsystems¶

Filtering may be applied by subsystem (the part of ExaCheck that is generating the log). The list of subsystems available are:

announcer: The route announcement/withdrawal manager
configuration: Configuration manager
executor: The check executor
healthcheck: Messages from health checks themselves
logging: Messages from the logging manager
master: Messages from the master process
notification: Messages generated from notifications
utility: Various utilities that do not fit elsewhere
worker: Worker related messages

Checks¶

A list of health checks may be provided; events will only be sent to the logging target if they are generated by the defined health checks.

Examples¶

To configure both syslog and file based logging:

---

logging:

  # Basic file logger
  - method: file
    destination: /tmp/exacheck.log

  # Send logs for announce/withdraw events using TCP to 192.0.2.100 port 514
  - method: syslog
    destination: 192.0.2.100
    protocol: tcp
    events:
      - announce
      - withdraw

# The list of health checks
checks:
    - ...

For more complete examples, check the relevant method page.