wait-for-it.php

wait-for-it.php is a PHP implementation of the wait-for-it.sh script by Gilles Hall.

It can be both run as a standalone executable or included in PHP and used by calling the wait_for_it() function. As standalone script it can be used as a drop-in replacement for wait-for-it.sh.

Usage

From the command line

   wait-for-it.php <host>[:<port> | -p <port>] [options] [--] [command [args]]
   wait-for-it.php -h <host> -p <port> [options] [--] [command [args]]
   
   
  -h <host>, --host=<host>  Host or IP under test
  -p <port>, --port=<port>  TCP port under test. Alternatively, you specify the
                            host and port as host:port
  -s, --strict              Only execute subcommand if the test succeeds
  -q, --quiet               Don't output any status messages
  -t <timeout>, --timeout=<timeout>
                            Timeout in seconds, zero for no timeout
  -- command args             Execute command with args after the test finishes

From PHP:

function wait_for_it(string $address, int $timeout = 15, float &$time_waited = null): bool {}

Installation

As Composer package

You can install it globally to use it as a stand-alone command:

composer global require yogarine/wait-for-it

You can also install wait-for-it.php as a dependency of your project:

composer require yogarine/wait-for-it

This will allow you to use the wait_for_it() function.

Docker

wait-for-it.php is also available as a Docker image:

docker run yogarine/wait-for-it www.google.com:80 -- echo "google is up"

You can also easily copy the script in your own Dockerfiles:

# Copy wait-for-it.php from it's official Docker image.
COPY --from=yogarine/wait-for-it /usr/local/bin/wait-for-it /usr/local/bin/

Just keep in mind you'll need to have the pcntl extension installed.

Usage in PHP code

When installed as composer package wait-for-it.php is automatically included as helper file, and declares the wait_for_it() function.

It will wait and return true if the host came up, and false otherwise.

Examples

For example, let's test to see if we can access port 80 on www.google.com, and if it is available, echo the message google is up.

$ vendor/bin/wait-for-it -t 0 www.google.com:80 -- echo "google is up" www.google.com:80 -- echo "google is up"
wait-for-it: waiting 15 seconds for www.google.com:80
wait-for-it: www.google.com:80 is available after 0 seconds
google is up

You can set your own timeout with the -t or --timeout= option. Setting the timeout value to 0 will disable the timeout:

$ vendor/bin/wait-for-it -t 0 www.google.com:80 -- echo "google is up"
wait-for-it: waiting for www.google.com:80 without a timeout
wait-for-it: www.google.com:80 is available after 0 seconds
google is up

The subcommand will be executed regardless if the service is up or not. If you wish to execute the subcommand only if the service is up, add the --strict argument. In this example, we will test port 81 on www.google.com which will fail:

$ vendor/bin/wait-for-it www.google.com:81 --timeout=1 --strict -- echo "google is up"
wait-for-it: waiting 1 seconds for www.google.com:81
wait-for-it: timeout occurred after waiting 1 seconds for www.google.com:81
wait-for-it: strict mode, refusing to execute subprocess

If you don't want to execute a subcommand, leave off the -- argument. This way, you can test the exit condition of wait-for-it.php in your own scripts, and determine how to proceed:

$ vendor/bin/wait-for-it www.google.com:80
wait-for-it: waiting 15 seconds for www.google.com:80
wait-for-it: www.google.com:80 is available after 0 seconds
$ echo $?
0
$ vendor/bin/wait-for-it www.google.com:81
wait-for-it: waiting 15 seconds for www.google.com:81
wait-for-it: timeout occurred after waiting 15 seconds for www.google.com:81
$ echo $?
124