Execute a task only on first node from a pull

[alinalexandru]

Q	A
Issue Type	Feature Request
Deployer Version	N/A
Local Machine OS	N/A
Remote Machine OS	N/A

Description

For example you have to execute a command only once. I don't like a idea of hardcode o server name when defining a task.

Instead of doing

task('only:once', function (){
....
})->onHosts('frist.node')

I propose to have a method onFirstHost for example, that will limit the task execution to the first node from available.

task('only:once', function (){
....
})->onFirstHost()

If you consider that is an good idea, I can propose a PR with the implementation.

[richsage]

+1, I've used some variation of this before:

task('only:once', function () {
    static $runOnce = false;
    if ($runOnce) {
        return;
    }

    $runOnce = true;
    // ...
});

but would be good to make this a bit cleaner.

[antonmedv]

But I think good naming required here. Maybe once?

task('only:once', function () {
....
})->once()

[alinalexandru]

@antonmedv what do you think about this PR.
I am open to any feedback

[antonmedv]

Merged!