@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)
- granules (string [stringified array of objects])
- parentArn (string)
- stackName (string)
- version (string)
- asyncOperationId (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({ [asyncOperationId], [executions], [granules], [parentArn], [sender], [stackName], [version] })
asyncOperationId
Type: string
An optional async operation id associated with a workflow.
executions
Type: string
An optional description of the executions.
granules
type: string
An optional granules string. Generally a stringified array of granule objects.
parentArn
type: string
An optional stepfunction ARN of the parent workflow that triggered the current execution.
sender
Type: string
The sender of the log event. Typically a Lambda Function Name or ECS Task Name. Defaults to "unknown".
stackName
type: string
Cumulus stack name.
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().
About Cumulus
Cumulus is a cloud-based data ingest, archive, distribution and management prototype for NASA's future Earth science data streams.
Contributing
To make a contribution, please see our contributing guidelines.