golog

golog is a simple and efficient log parsing and formatting tool. It allows you to define templates to extract and present log data in a structured and readable way.

🚀 Getting Started

Installation

Binary Installation (Recommended)

# Install the latest version
go install github.com/gitKashish/golog@latest

This will install the golog binary to your $GOPATH/bin directory (or $GOBIN if set). Make sure this directory is in your PATH.

Building from Source

# Clone repository
git clone https://github.com/gitKashish/golog.git

# Build binary
cd golog
go build

This will create a golog executable in your current directory.

Creating template.yaml

golog relies on a template.yaml file to define how logs should be parsed and formatted. Create this file in the same directory as the golog binary.

📄 Template Format

The template.yaml file defines two key templates: sourceTemplate and targetTemplate.

1. sourceTemplate

The sourceTemplate describes the structure of your incoming log lines. It uses a specific format for defining fields:

@fieldName-fieldType@

• fieldName: The name of the field (must be unique, alphanumeric characters and underscores only).
• fieldType: The data type of the field.

Supported Field Types:

Type	Symbol	Description
Raw	raw	Value is returned as is (no formatting).
Number	number	Value is treated as a number.
String	string	Value is treated as a string.
JSON	json	Value is parsed as a JSON string and pretty-printed.
Timestamp	timestamp	Value is parsed as a timestamp and formatted into RFC822Z format.
Default	N/A	Used internally when the log doesn't match the sourceTemplate.

2. targetTemplate

The targetTemplate defines how the output should be formatted. It uses the field names defined in the sourceTemplate:

@fieldName@

A field name can be used multiple times in the targetTemplate.

✨ Example

Log Input:

5|3022  | -->2025-01-24 07:29:52.954 :----: users :=: updateJobStatus :=: {"EVENT":"deleteNotificationTaskFromScheduler","ERROR":{"errno":-110,"code":"ETIMEDOUT","syscall":"connect","address":"52.41.75.101","port":3013}}

template.yaml:

sourceTemplate: "@server-number@|@instance-number@  | -->@time-timestamp@ :----: @module-string@ :=: @api-string@ :=: @details-json@"
targetTemplate: |
  ---------------------------
  Server: @server@
  Instance: @instance@
  Timestamp: @time@
  API: @api@
  Module : @module@
  Details: @details@
  ---------------------------

🔎 Usage

golog write

Formats log and writes to a specified file.

golog write -i <input_file> -o <output_file> [-s]

• -i, --input string: Path to the input log file (required).
• -o, --output string: Path to the output file (required).
• -s, --show: Also print the output to the console.

golog show

Formats log and prints the output to the console.

golog show -i <input_file>

• -i, --input string: Path to the input log file (required).

⚙️ Development

Go v1.20 or later is recommended.

🤝 Contributing

Contributions are welcome! Please open an issue or submit a pull request.

📄 License

This project is licensed under the GNU Lesser General Public License v3.0. See the LICENSE file for details.