wait-for/README.md

# wait-for

[![Build Status](https://img.shields.io/drone/build/thegeeklab/wait-for?logo=drone)](https://cloud.drone.io/thegeeklab/wait-for)
[![GitHub contributors](https://img.shields.io/github/contributors/thegeeklab/wait-for)](https://github.com/thegeeklab/wait-for/graphs/contributors)
[![License: MIT](https://img.shields.io/github/license/thegeeklab/wait-for)](https://github.com/thegeeklab/wait-for/blob/master/LICENSE)

wait-for is a script designed to synchronize services like docker containers. It is [sh](https://en.wikipedia.org/wiki/Bourne_shell) and [alpine](https://alpinelinux.org/) compatible. It was inspired by [vishnubob/wait-for-it](https://github.com/vishnubob/wait-for-it), but the core has been rewritten at [Eficode](http://eficode.com/) by [dsuni](https://github.com/dsuni) and [mrako](https://github.com/mrako).

When using this tool, you only need to pick the `wait-for` file as part of your project.

## Usage

```Shell
$ wait-for --help
usage: wait-for host:port [-t timeout] [-- command args]

Synchronize services like docker containers and wait for readiness.

optional arguments:
  -q | --quiet                              Do not output any status messages
  -t WAITFOR_TIMEOUT | --timeout=timeout    Timeout in seconds, zero for no timeout
  -- COMMAND ARGS                           Execute command with args after the test finishes
```

## Dependencies

* Installed Netcat

## Examples

To check if [eficode.com](https://eficode.com) is available:

```Shell
$ ./wait-for www.eficode.com:80 -- echo "Eficode site is up"

Eficode site is up
```

To wait for database container to become available:

```Yaml
version: '2'

services:
  db:
    image: postgres:9.4

  backend:
    build: backend
    command: sh -c './wait-for db:5432 -- npm start'
    depends_on:
      - db
```

## Contributors

Special thanks goes to all [contributors](https://github.com/thegeeklab/wait-for/graphs/contributors).

## License

This project is licensed under the MIT License - see the [LICENSE](https://github.com/thegeeklab/wait-for/blob/master/LICENSE) file for details.