Powerful terminal based viewer for JSON logs using ncurses.

json-log-viewer is a feature intensive viewer and analyze tool for JSON logs created by libraries like https://github.com/winstonjs/winston.

Features:

• completely operated by hotkeys
• powerful command line arguments
• sort by timestamp, level or message
• filter by any field or metadata
• search

Hotkeys:

• arrows and page up/down to move
• / to search
• n to search again
• s to sort
• f to filter
• l to filter by level
• g to go to line
• 0 to go to first line
• $ to go to last line
• q to quit

npm install --global json-log-viewer

jv application.log.2017-01-01 --sort -timestamp

The default expected log format include fields timestamp, level and message. If your log file doesn't include these fields, you can override the default configuration by creating a .json-log-viewer file in either your HOME path or current working directory. It's worth noting that if you create a config.json file in your current working directory, it will take precedence over any file located in your HOME path."

For example, if your log lines look like this:

{
  "message":
    "Matched route \"**_heartbeat_check\" (parameters: \"_controller\": \"**\\Controller\\**Controller::heartbeatCheckAction\", \"_route\": \"**_heartbeat_check\")",
  "context": [],
  "level": 200,
  "level_name": "INFO",
  "channel": "request",
  "datetime": {
    "date": "2017-12-06 09:23:42.253060",
    "timezone_type": 3,
    "timezone": "Europe/Berlin"
  },
  "extra": []
}

You can create a mapping configuration like this:

[transform]
level=level_name
timestamp=datetime.date
message=message
extra=$

This way the messages will properly be displayed. The $ has a special meaning: it tells the the old object should be included on the extra key on the resulting JSON. The result will look like this:

Details view

Filters

Log level selection

MIT