Pretty Log

Displaying tool for JSON structured logs in compatible format to humans.

Installation

curl https://github.com/globocom/prettylog/raw/master/install.sh | sh

Assuming that the folder $GOPATH/bin is inside the user's actual PATH, the application will be available after the installation.

Running

Prettylog processes logs containing an arbitrary number of fields, and creates a friendly output in the following format:

<TIMESTAMP> <LOGGER> <CALLER> <LEVEL> <MESSAGE> <FIELD1>=<VALUE> <FIELD2>=<VALUE> ...

If a specific field does not exist in the log, it will be ignored on the output.

NOTE: Nowadays, only logs on JSON format are supported. Logs in another format, or without one, will be printed without any modification

Utilization

The tool was designed to read directly the stdout from an application that produces logs in a structured format:

app | prettylog

If the application writes logs on sterr instead of stdout, a redirect is required so the tool can work properly:

app 2>&1 | prettylog

Settings

The tool can be configured through the .prettylog.yml file, which can be found either locally(on the folder that the tool runs) or globally (in the folder $HOME). The file structure is as follows:

timestamp: key: visible: color:

logger:
  key:     <string>
  visible: <bool>
  padding: <int>
  color:   <list of int>

caller:
  key:     <string>
  visible: <bool>
  padding: <int>
  color:   <list of int>

level:
  key:     <string>
  visible: <bool>
  padding: <int>
  colors:
    debug: <list of int>
    info:  <list of int>
    warn:  <list of int>
    error: <list of int>
    fatal: <list of int>

message:
  key:     <string>
  padding: <int>
  color:   <list of int>

Each key configures the format of the field in the log, and the meaning of each property is described bellow:

key: Name of the field that will be extracted from the log of the application.
visible: Flag indicating whether the field will be displayed by the tool or not.
padding: Amount of blank spaces that will be added to the right of the field text.
color/colors: Color attributes used for coloring the field text. Up to 3 values can be entered (foreground, background e effects) according to ASCII colors chart.

Utilization with other command line tools

Prettylog can be used with other processing output tools like grep. However, for the formatting of the output to be done correctly, it is necessary to turn off any non-line buffer. For example, with grep just use the --line-buffered option:

app | grep --line-buffered -v debug | prettylog