log4js-knex

This is a node log4js appender that uses knex as a database connection interface.

You can use it with a standard configuration as follows:

var log4js = require('log4js');
log4js.configure({
    appenders: {
        database: {
            "type": "log4js-knex",
            "table": "log",
            "knex": {
                "client": "sqlite",
                "connection": {
                    "filename": "./log.sqlite3"
                },
                "useNullAsDefault": true
            },
            "additionalFields": {
                "serverName": "www.google.ca"
            }
        }
    },
    categories: { default: { appenders: ['database'], level: 'debug' } }
})

var logger = log4js.getLogger();
logger.debug("Added debug");

The default table name is log, although that can be overridden by passing the table option as shown above. The appender does not attempt to create this table. This is a change from previous versions, but it's more sensible for security reasons to limit permissions to those needed to manage data insertion only. If you're using Knex.js, one extra migration is simple anyway. In Knex.js, a schema change like this can be used:

return knex.schema.createTable(tableName, function (table) {
  table.increments();
  table.bigInteger('time').notNullable();
  table.string('data', 4096).notNullable();
  table.integer('rank').notNullable();
  table.string('level', 12).notNullable();
  table.string('category', 64).notNullable();
  table.index('time');
});

The additionalFields property allows you to set some fields that get merged into every log record as additional columns. They're handy in tracing sources. Normally you are unlikely to need these, however.

Note that the time is written as a big integer, rather than as a string. This is because we need fine grained times, and timestamps don't usually provide them. If you need better timing, you can process that later, even in SQL you can usually handle that through a function.

Author

Stuart Watt

License

The MIT License (MIT)

Copyright (c) 2014-2018 Stuart Watt

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.