rtail(1) - Terminal output to the browser in seconds, using UNIX pipes.
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README.md

rtail(1)

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Terminal output to the browser in seconds, using UNIX pipes.

rtail is a command line utility that grabs every line in stdin and broadcasts it over UDP. That's it. Nothing fancy. Nothing complicated. Tail log files, app output, or whatever you wish, using rtail broadcasting to an rtail-server – See multiple streams in the browser, in realtime.

Installation

$ npm install -g rtail

Web app

Rationale

Whether you deploy your code on remote servers using multiple environments or simply have multiple projects, you must ssh to each machine running your code, in order to monitor the logs in realtime.

There are many log aggregation tools out there, but few of them are realtime. Most other tools require you to change your application source code to support their logging protocol/transport.

rtail is meant to be a replacement of logio, which isn't actively maintained anymore, doesn't support node v0.12., and uses TCP. (TCP requires strict client / server handshaking, is resource-hungry, and very difficult to scale.)

The rtail approach is very simple:

  • pipe something into rtail using UNIX I/O redirection [2]
  • broadcast every line using UDP
  • rtail-server, if listening, will dispatch the stream into your browser, using socket.io.

rtail is a realtime debugging and monitoring tool, which can display multiple aggregate streams via a modern web interface. There is no persistent layer, nor does the tool store any data. If you need a persistent layer, use something like loggly.

Examples

In your app init script:

$ node server.js 2>&1 | rtail --id "api.myproject.com"

$ mycommand | rtail > server.log

$ node server.js 2>&1 | rtail --mute

Supports JSON5 lines:

$ while true; do echo [1, 2, 3, "hello"]; sleep 1; done | rtail
$ echo { "foo": "bar" } | rtail
$ echo { format: 'JSON5' } | rtail

Using log files (log rotate safe!):

$ node server.js 2>&1 > log.txt
$ tail -F log.txt | rtail

For fun and debugging:

$ cat ~/myfile.txt | rtail
$ echo "Server rebooted!" | rtail --id `hostname`

Params

$ rtail --help
Usage: cmd | rtail [OPTIONS]

Options:
  --host, -h     The server host                 [string] [default: "127.0.0.1"]
  --port, -p     The server port                        [string] [default: 9999]
  --id, --name   The log stream id                 [string] [default: (moniker)]
  --mute, -m     Don't pipe stdin with stdout                          [boolean]
  --tty          Keeps ansi colors                     [boolean] [default: true]
  --parse-date   Looks for dates to use as timestamp   [boolean] [default: true]
  --help         Show help                                             [boolean]
  --version, -v  Show version number                                   [boolean]

Examples:
  server | rtail > server.log         localhost + file
  server | rtail --id api.domain.com  Name the log stream
  server | rtail --host example.com   Sends to example.com
  server | rtail --port 43567         Uses custom port
  server | rtail --mute               No stdout
  server | rtail --no-tty             Strips ansi colors
  server | rtail --no-date-parse      Disable date parsing/stripping

rtail-server(1)

rtail-server receives all messages broadcast from every rtail client, displaying all incoming log streams in a realtime web view. Under the hood, the server uses socket.io to pipe every incoming UDP message to the browser.

There is little to no configuration – The default UDP/HTTP ports can be changed, but that's it.

Examples

Use default values:

$ rtail-server

Always use latest, stable webapp:

$ rtail-server --web-version stable

Use custom ports:

$ rtail-server --web-port 8080 --udp-port 9090

Set debugging on:

$ DEBUG=rtail:* rtail-server

Open your browser and start tailing logs!

Params

$ rtail-server --help
Usage: rtail-server [OPTIONS]

Options:
--udp-host, --uh  The listening UDP hostname            [default: "127.0.0.1"]
--udp-port, --up  The listening UDP port                       [default: 9999]
--web-host, --wh  The listening HTTP hostname           [default: "127.0.0.1"]
--web-port, --wp  The listening HTTP port                      [default: 8888]
--web-version     Define web app version to serve                     [string]
--help, -h        Show help                                          [boolean]
--version, -v     Show version number                                [boolean]

Examples:
rtail-server --web-port 8080         Use custom HTTP port
rtail-server --udp-port 8080         Use custom UDP port
rtail-server --web-version stable    Always uses latest stable webapp
rtail-server --web-version unstable  Always uses latest develop webapp
rtail-server --web-version 0.1.3     Use webapp v0.1.3

UDP Broadcasting

To scale and broadcast on multiple servers, instruct the rtail client to stream to the broadcast address. Every message will then be delivered to all servers in your subnet.

Authentication layer

For the time being, the webapp doesn't have an authentication layer; it assumes that you will run it behind a VPN or reverse proxy, with a simple Authorization header check.

How to contribute

This project follows the awesome Vincent Driessen branching model.

  • You must add a new feature on its own branch
  • You must contribute to hot-fixing, directly into the master branch (and pull-request to it)

This project uses JSCS to enforce a consistent code style. Your contribution must be pass jscs validation.

The test suite is written on top of mochajs/mocha. Use the tests to check if your contribution breaks some part of the library and be sure to add new tests for each new feature.

$ npm test

Contributors

Roadmap (aka where you can help)

  • Write a rock solid test suite
  • Allow use of DTLS (waiting for node to support this https://github.com/joyent/node/pull/6704)
  • Add GitHub OAuth and basic auth for teams (join proposal convo here: https://github.com/kilianc/rtail/issues/44)
  • Implement infinite-scroll like behavior in the webapp to support bigger backlogs and make it future proof.
  • Publish base rtail docker image to DockerHub
  • Create a catch all docker logs image
  • Rewrite webapp using ng2

Sponsors

❤ rTail? Consider sponsoring this project to keep it alive and free for the community.

  • Lukibear (domain)
  • ? (wildcard TLS cert)
  • ? (.io domain)

PayPal donate button

Professional support or ad-hoc is also available.

License

This software is released under the MIT license cited below.

Copyright (c) 2014 Kilian Ciuffolo, me@nailik.org. All Rights Reserved.

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the 'Software'), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.