tailchart

A smarter way to follow files and logs.

Install

npm install -g tailchart

Usage

tailchart

Make the assumption that you have a config.json file in the current directory.

You can specific the path of the configuration file by using the tailchart --config mypath/conf.json

Once running, press "r" to reset the value in the different widgets.

Configuration

At this point in time, tailchart require a configuration file to starts.

When running, tailchart display info of the full surface of the terminal window. You position and size the different widgets by using a grid system.

Below is an example of a valid configuration (comments are automatically stripped out):

{
  // Required, only one value for now
  "version": "1.0",

  // Required. Path to the fail we will tail
  "source": "/var/log/system.log",

  // Required. Must be an array of objects
  "widgets": [
    // Raw Log Widget
    // Display all log lines
    {
      "type": "raw",      // required
      "name": "Raw Logs", // Required, must unique accross all widgets
      "col": 0,     // required, integer
      "colspan": 1, // required, integer
      "row": 0,     // required, integer
      "rowspan": 1, // required, integer
      
      "prefixTrimIndex": 0, // optional, integer. Remove the N first character of the line
      "highlights": {
        "lines": [ // optional, array. Each line match will be printed in the specified color
          {
            "color": "red",   // required, string
            "match": "error" // required, string that compile to a valid regular expression
          }
        ]        
      }
    },
    
    // Filter Log Widget
    // Display only the log lines that match a regular expression. 
    // + all functionnality of raw
    {
      "type": "filter",   // required
      "name": "Raw Logs", // Required, must unique accross all widgets
      "col": 0,     // required, integer
      "colspan": 1, // required, integer
      "row": 0,     // required, integer
      "rowspan": 1, // required, integer
      
      // Specific options
      "match": "error|warning", // required, string compiling to regular expression. Define what is capture by widget
      
      // Options inherited from RawLog
      "prefixTrimIndex": 0, // optional, integer. Remove the N first character of the line
      "highlights": {
        "lines": [ // optional, array. Each line match will be printed in the specified color
          {
            "color": "red",   // required, string
            "match": "error"  // required, string that compile to a valid regular expression
          }
        ]        
      }
    },

    // Split Counter Widget
    {
      "type": "splitCounter",         // required 
      "name": "Sonos App Error type", // Required, must unique accross all widgets
      "col": 3,     // required, integer
      "colspan": 1, // required, integer
      "row": 0,     // required, integer
      "rowspan": 1, // required, integer
      
      // Specific options
      "match": "<Error> ([a-z]+)" // require, string compiling to regular expression.
                                  // must have 1 capturing group
    }
  ]
}

Widgets

RawLog

Display all the logs line. Optionally:

• trim the N first character of the line (perfect to remove useless prefix)
• display in a specific color lines matching a regular expression

{
  "type": "raw", // required
  "name": "Raw Logs", // Required, must unique accross all widgets
  "col": 0, // required, integer
  "colspan": 3, // required, integer
  "row": 0, // required, integer
  "rowspan": 3, // required, integer
  "prefixTrimIndex": 0, // optional, integer. Remove the N first character of the line
  "highlights": {
    // optional, objecct
    "lines": [
      {
        "color": "red",
        "match": "error"
      },
      {
        "color": "yellow",
        "match": "warning"
      }
    ]
  }
}

FilterLog

Same functionality as RawLog with the twist that it display only the lines that are matching a regular expression.

{
  "type": "filter",
  "name": "Errors and Warnings",
  "col": 0, // required, integer
  "colspan": 3, // required, integer
  "row": 3, // required, integer
  "rowspan": 1, // required, integer

  "match": "error|warning",

  "prefixTrimIndex": 0, // optional, integer. Remove the N first character of the line
  "highlights": {
    // optional, objecct
    "lines": [
      {
        "color": "red",
        "match": "error"
      },
      {
        "color": "yellow",
        "match": "warning"
      }
    ]
  }
}

Counter

Count how many times something happen, and its frequency compare to other match. Perfect to visualize the distribution of error, type of queries, status code, etc

{
      "type": "counter",
      "name": "Sonos App Error type",
      "match": "<Error> ([a-z]+)",
      "col": 3,
      "colspan": 1,
      "row": 0,
      "rowspan": 2
    }

Dreamlist

• Read from stdin to allow piping
• Zero config start
• In program UI to add/modify/remove widgets
• Config import (like blue print in Factorio)
• Save / Load config
• Replay logs