Why do you ask?

So I can frame the question better, and because I can't really think of any other purpose for the hook :)

I think you'll find https://metacpan.org/pod/Plack::Handler::Apache2#STARTUP-FILE interesting, as well as https://metacpan.org/pod/Plack::Component#OBJECT-LIFECYCLE and especially https://metacpan.org/pod/Plack::Builder#INLINE-MIDDLEWARE

So you can create your own init_hook as an anonymous inline Plack::Middleware 

builder {
  ...
  enable \&child_init_phase;
  $app;
};
...
sub child_init_phase {
    my( $app ) = @_;
    ...   ## your init stuff here
    $app; ## return app unmodified
}

[download]
Thats your PlackChildInitHandler

In reply to Re^3: Plack and apache child init phase (PlackChildInitHandler) by Anonymous Monk
in thread Plack and apache child init phase by ysth

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.