javascript appender

Create appender for log4js-node to enable RELP usage from node.js applications.

User Story: As a developer I would like to use jsa_01 to push log messages over relp to a compatible relp-server with syslog envelope

== Specs

^^^^^ Requirements Backlog [options="header,footer"] |======================= |# |Title |User Story |Importance |Status |1 |Rebind |Rebind of the rlp_02 connection must be done after configureable amount of messages | OPTIONAL |Open |2 |Syslog |Wrap messages in syslog envelope |Must Have |WIP |3 |RELP |Use rlp_02 library |Must Have |Done |4 |Lossless|Retry indefinitely and do not lose messages |Must Have |Open |5 |Robust|Processing must not hang indefinitely due to techinical issues but rather retry new connection |Must Have |Open |6 |Source Data |Must include origin data in syslog structure-data within source-metadata | Must Have |WIP |7 |Originator |Must include hostname within new syslog structured-data (SD) so utilization systems can utilize it |Must Have |Done |8 |app-name |Syslog app-name must be configureable |Must Have |Done |9 |hostname|syslog hostname must be configureable |Must Have |Done |10 |server port|Server ports need to be configureable |Must Have |Done |11 |Server address |server address needs to be configureable | Must Have |Done |12 |Expose error SyslogMessage |Erros(expecptions) must not be hidden |Must Have |Open |13 |Extra libraries |Do not use extra libraries |Must Have |Open |14 |Variable checking|Check variables provided via configuration to be valid and raise errors if not in initilization |Must Have |Done |15 |Debug flags|Allow passing debulg flags via configuration |OPTIONAL |Open

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== High-level Architecture

image::https://github.com/teragrep/jsa_01/blob/base-feat/images/JSA_01.png[]

== Implementation

The jsAppender to push log messages over relp to a compatible relp-server with syslog envelope. For the RELP connection - rlp_02 + Generate the Syslog message - rlo_08 + RELP compatible server - Java-relp-server-demo (tested on)

• asynchronus behaviour completely controlled by the Jasmine async works.

[source,node]

npm install

• Module usage:

• The appender uses the rlo_08 for handling formatting log messages and rlp_02 to send the log event message to the RELP Server. [source,javascript]

const { SyslogMessage, Facility, SDElement, SDParam, Severity } = require('@teragrep/rlo_08') const { RelpConnection, RelpBatch } = require('@teragrep/rlp_02')

• Build

[source,java]

mvn clean package

• OPTIONAL TIPS

async waterfall method also possible for run in the node engine (need to adjust the code).

== Configuration

• *_type_* - *_jsAppender_*
• *_hostname_* - *_string_* (defaults to os.hostname()) - origin of the log messages
• *_appname_* - *_string_*
• *_serverAddress_* - *_string_*
• *_serverPort_* - *_integer_* (defaults to 1601) - Port of the relp server is listening in

== Example (default config) [source,javascript]

log4js.configure( { appenders: {jsa: { type: jsAppender, appName: 'teragrep' }, console: { type: 'console' }, }, categories: { jsa: { appenders: ['jsa'], level: 'error' }, default: { appenders: ['jsa'], level: 'trace' }, }, })

This configuration will send the log event messages to the RELP Server.