ftail

ftail is a log tailing library, configurable with yaml, symfony/expression-language, and php.

It allows you to tail a log file in the format that you like. It also allows you to exclude certain lines you don't want to see, and/or to replace content for a specific purpose.

⚠️ At the moment, you need logs formatted in json. Check out troubleshooting for more information.

Requirements

• php 8+
• composer
• tail

Installation

• Install dependencies:

composer install

• You might want to add the binary path to your ~/.bashrc or ~./zshrc:

echo 'export PATH="/path/to/ftail/bin:$PATH"' >> ~/.zshrc

source ~/.zshrc

Usage

• Assuming you added the ftail binary path to your $PATH:

ftail path/to/file.log
ftail path/to/file.log -c plain   # select a configuration from the ./config directory
ftail path/to/file.log -l warning # set the minimum log level to `warning`
ftail path/to/file.log -cn event  # restrict log entries to the `event` channel
ftail path/to/file.log --help     # for help

• The default configuration is config/library/colored.yaml
• ftail is also shipped with a non-colored version config/library/plain.yaml:

Custom configuration

One of the main interest of ftail is to be able to create a custom configuration for each project or use case that you have, so that you can read your logs comfortably.

• Copy the config.dist.yaml to ./config/my_config.yaml
• Then you can use it like this:

ftail -c my_config path/to/file.log

---

Each configuration allows you to customize your own:

• line reader: how do you read a line from the log file (tail is the default and only one at the moment)
• line decoder: how do you decode a single line (json is the default and only one at the moment)
• line formatter: how do you display a single log line
• exclusions: exclude certain lines using Symfony Expression Language.
• replacements: replace anything within a log line message

Check out config.dist.yaml and ColoredFormatter and PlainFormatter for more information on how to create your configurations.

Also check the Symfony Expression Language syntax.

Troubleshooting

I'm using Symfony with Monolog in a project, but it does not have json logs, and I don't want to alter the configuration for everyone.

A solution would be to create a folder inside your packages, with your configuration:

└── packages
    ├── ftail
    │   ├── .gitignore   # just add a * in the file and the directory won't be tracked
    │   └── monolog.yaml # your configuration with json logs
    └── monolog.yaml     # project configuration

How do I configure monolog to output json within a Symfony project?

Like this:

monolog:
  handlers:
    main:
      type: stream
      path: "%kernel.logs_dir%/%kernel.environment%.log"
      formatter: 'monolog.formatter.json' # add this line

Contributing

Feel free to create your own readers, decoders & formatters. Add them to this repository if you think they might be useful to others.