@cumulus/logger
A logging library for use on the Cumulus project.
The @cumulus/logger
library exports a Logger
class, which generates
JSON-formated log events.
Log events always have the following keys:
- level (string) - the priority level of the message
- message (string) - the message itself
- sender (string) - the resource that created the message
- timestamp (string) - an ISO-8601 timestamp
Log events may have the following options keys:
- executions (string)
- version (string)
Log events may also contain user-specified keys.
Example log event:
{
"level": "info",
"message": "hello world",
"sender": "greetingFunction",
"timestamp": "2018-10-19T19:12:47.501Z"
}
Install
$ npm install @cumulus/logger
Usage
const Logger = require('@cumulus/logger');
const log = new Logger({ sender: 'example' });
log.info('hello, world');
API
new Logger({ [sender], [executions], [version] })
sender
Type: string
The sender of the log event. Typically a Lambda Function Name or ECS Task Name.
Defaults to "unknown".
executions
Type: string
An optional description of the executions.
version
Type: string
An optional version.
log.debug([...messageArgs])
Writes a log event to stdout with level set to "debug".
args
Type: ...any
See console.log().
log.error([...messageArgs][, error])
Writes a log event to stderr with level set to "error".
args
Type: ...any
See console.log().
error
Type: Error
If the last argument is an Error then the following additional properties will be set on the log event:
- error (Object)
- name (string)
- message (string)
- stack (Array<string>) - the lines of the stack trace
log.fatal([...messageArgs])
Writes a log event to stdout with level set to "fatal".
args
Type: ...any
See console.log().
log.info([...messageArgs])
Writes a log event to stdout with level set to "info".
args
Type: ...any
See console.log().
log.infoWithAdditionalKeys(additionalKeys, ...messageArgs)
Writes a log event to stdout with level set to "info". In addition to the
standard keys, additional keys will be added to the event. If an additional key
is specified with the same name as a standard key, the value standard key will
be displayed.
additionalKeys
Type: Object
Additional key/value pairs to be added to the event.
args
Type: ...any
See console.log().
log.trace([...messageArgs])
Writes a log event to stdout with level set to "trace".
args
Type: ...any
See console.log().
log.warn([...messageArgs])
Writes a log event to stdout with level set to "debug".
args
Type: ...any
See console.log().
What is Cumulus?
Cumulus is a cloud-based data ingest, archive, distribution and management
prototype for NASA's future Earth science data streams.
Cumulus Documentation
Contributing
See Cumulus README