https://github.com/joaodrp/gelf-pretty
CLI to pretty-print GELF log lines
https://github.com/joaodrp/gelf-pretty
cli gelf graylog log logging pretty-print
Last synced: 11 months ago
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CLI to pretty-print GELF log lines
- Host: GitHub
- URL: https://github.com/joaodrp/gelf-pretty
- Owner: joaodrp
- License: mit
- Created: 2019-03-30T12:01:10.000Z (about 7 years ago)
- Default Branch: master
- Last Pushed: 2023-02-25T02:49:34.000Z (over 3 years ago)
- Last Synced: 2025-04-05T05:03:19.844Z (about 1 year ago)
- Topics: cli, gelf, graylog, log, logging, pretty-print
- Language: Go
- Homepage:
- Size: 50.8 KB
- Stars: 6
- Watchers: 2
- Forks: 0
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Contributing: CONTRIBUTING.md
- License: LICENSE
- Code of conduct: CODE_OF_CONDUCT.md
Awesome Lists containing this project
README
gelf-pretty
CLI to pretty-print GELF log lines
---
## Introduction
CLI tool to read Graylog
Extended Log Format (GELF) log lines from `stdin`, such as:
```text
{"version":"1.1","host":"my-server","short_message":"Starting server","timestamp":1555690413.839,"level":6,"_app":"my-app","_logger":"api","_port":"3000"}
{"version":"1.1","host":"my-server","short_message":"Listening for requests","timestamp":1555690413.903,"level":6,"_app":"my-app","_logger":"api","_endpoint":"locahost:3000/v1"}
{"version":"1.1","host":"my-server","short_message":"Request received","timestamp":155569049.540,"level":6,"_app":"my-app","_logger":"api","_method":"GET","_path":"/todos/1","_request_id":"0c4c165d"}
{"version":"1.1","host":"my-server","short_message":"Response","full_message":"{\n\t\"user_id\": 1,\n\t\"id\": 1,\n\t\"title\": \"fix /users/:id/todos route\",\n\t\"completed\": false\n}","timestamp":155569049.584,"level":7,"_app":"my-app","_logger":"api","_request_id":"0c4c165d","_status":200}
{"version":"1.1","host":"my-server","short_message":"Request received","timestamp":155569349.236,"level":6,"_app":"my-app","_logger":"api","_method":"GET","_path":"/users/1/todos","_request_id":"0c4c165d"}
{"version":"1.1","host":"my-server","short_message":"Unexpected error","full_message":"runtime error: index out of range\ngoroutine 1 [running]:\nmain.main()\n\t/app/api/main.go: 9 +0x20","timestamp":155569349.563,"level":3,"_app":"my-app","_logger":"api","_request_id":"0c4c165d"}
{"version":"1.1","host":"my-server","short_message":"Server shutting down","timestamp":155569349.571,"level":4,"_app":"my-app","_logger":"api"}
```
And pretty-print them to `stdout` like:
## Installation
You can install `gelf-pretty` using one of the following options:
- Pre-built packages for macOS and Linux (easiest);
- Pre-compiled binaries for macOS, Linux and Windows;
- From source.
### Pre-built packages
#### macOS
Install via [Homebrew](https://brew.sh/):
```bash
$ brew install joaodrp/tap/gelf-pretty
```
#### Linux
Install via [Snapcraft](https://snapcraft.io/gelf-pretty):
```bash
$ snap install gelf-pretty
```
You can also download `.deb` or `.rpm` packages from the [releases
page](https://github.com/joaodrp/gelf-pretty/releases) and install with `dpkg
-i` or `rpm -i` respectively.
### Pre-compiled binaries
Download the correct archive for your platform from the [releases
page](https://github.com/joaodrp/gelf-pretty/releases) and extract the
`gelf-pretty` binary to a directory included in your `$PATH`/`Path`.
### From source
```bash
$ go get -u github.com/joaodrp/gelf-pretty
```
Make sure that the `$GOPATH/bin` folder is in your `$PATH`.
## Output Format
GELF messages are pretty-printed in the following format:
```text
[] : <_app>/<_logger> on : <_*>=\n
```
### Description
- `` is the value of the standard GELF unix `timestamp` field,
formatted as `2006-01-02 15:04:05.000`;
- `` is the value of the standard GELF log `level` field, formatted in a
human-readable form (e.g. `DEBUG` instead of `7`);
- `<_app>` is an optional *reserved* additional field. It can be used to
identify the name of the application emitting the logs. If not provided, the
forward slash that follows it is omitted;
- `<_logger>` is an optional *reserved* additional field. It can be used to
identify the specific application module or logger instance that is emitting a
given log line;
- `` is the value of the standard GELF `host` field;
- `` is the value of the standard GELF `short_message` field;
- `<_*>=` is any number of GELF additional fields (`_*`), formatted as
`key=value` pairs separated by a whitespace. The keys leading underscore is
omitted for readability;
- `` is the value of the standard GELF `full_message` field
(usually used for exception backtraces). It is preceded by a new line and
indented with four spaces.
### Colors
`gelf-pretty` automatically detects if the output stream is a `TTY` or not. If
(and only if) it is, the output will be formatted by default with ANSI colors
for improved readability.
## Usage
To pretty-print GELF logs from your application simply pipe its output to
`gelf-pretty`:
```bash
$ app | gelf-pretty
```
Run `gelf-pretty --help` for a list of available options:
```bash
$ gelf-pretty --help
Usage of gelf-pretty:
--no-color
Disable color output
--version
Show version information
```
### Capture stderr
If your application writes to the `stderr` stream you will need to pipe it along
with `stdout`:
```bash
$ app 2>&1 | gelf-pretty
```
### Disable colors
To disable colored output (even if the output stream is a `TTY`) use the
`--no-color` option:
```bash
$ app | gelf-pretty --no-color
```
## FAQ
### My logs are not formatted, why?
`gelf-pretty` validates each input line. If a line (delimited by `\n`) is not a
valid JSON string or is invalid according to the [GELF
specification](http://docs.graylog.org/en/latest/pages/gelf.html#gelf-payload-specification),
`gelf-pretty` will simply echo it back to the `stdout` without any modification
(silently, with no error messages).
If you believe that your log messages are valid, please [open a new
issue](https://github.com/joaodrp/gelf-pretty/issues/new) and let us know.
## Contributions
This project adheres to the Contributor Covenant [code of
conduct](CODE_OF_CONDUCT.md). By participating, you are expected to uphold this
code. Please refer to our [contributing guide](CONTRIBUTING.md) for further
information.